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Giant taro and its relatives: A phylogeny of the large genus Alocasia (Araceae) sheds light on Miocene floristic exchange in the Malesian region
Abstract
Alocasia comprises over 113 species of rainforest understorey plants in Southeast Asia, the Malesian region, and Australia. Several species, including giant taro, Alocasia macrorrhizos, and Chinese taro, Alocasia cucullata, are important food plants or ornamentals. We investigated the biogeography of this genus using plastid and nuclear DNA sequences (5200 nucleotides) from 78 accessions representing 71 species, plus 25 species representing 16 genera of the Pistia clade to which Alocasia belongs. Divergence times were inferred under strict and relaxed clock models, and ancestral areas with Bayesian and maximum likelihood approaches. Alocasia is monophyletic and sister to Colocasiagigantea from the SE Asian mainland, whereas the type species of Colocasia groups with Steudnera and Remusatia, requiring taxonomic realignments. Nuclear and plastid trees show topological conflict, with the nuclear tree reflecting morphological similarities, the plastid tree species' geographic proximity, suggesting chloroplast capture. The ancestor of Alocasia diverged from its mainland sister group c. 24 million years ago, and Borneo then played a central role in the expansion of Alocasia: 11-13 of 18-19 inferred dispersal events originated on Borneo. The Philippines were reached from Borneo 4-5 times in the Late Miocene and Early Pliocene, and the Asian mainland 6-7 times in the Pliocene. Domesticated giant taro originated on the Philippines, Chinese taro on the Asian mainland.
... As a part of the Malesia region, Indonesia has a humid tropic climate and complex physiography which supports its rich biota [1]. One of them is Alocasia genus, whose main center of geographic expansion, diversity, and endemism is in Borneo [2,3], and the second is New Guinea/Australia [2]. Therefore, the two provinces of Indonesia (Kalimantan and Papua) are two regions of Alocasia diversity centers. ...
... Therefore, the two provinces of Indonesia (Kalimantan and Papua) are two regions of Alocasia diversity centers. Alocasia is distributed in the tropic and subtropic of mainland Asia, the Malesia region, to Oceania and Australia [3]. This genus is estimated to contain 121 species, of which 78 species have been described [4]. ...
... According to a phylogenetic tree constructed from chloroplast and mitochondrial DNA, Alocasia is a Pistia clade member, including the genera Arisaema, Colocasia, Pinellia, Steudnera, and Typhonium [9]. A molecular study was conducted and used the genus in the Pistia clade [3], where the Colocasia species were more numerous. This study discovered that Colocasia gigantea did not belong to the same clade as other Colocasia species, but instead formed a clade with Alocasia. ...
Phylogenetic analysis is beneficial to plant conservation prioritization. Conservation does not only deal with species but also their evolutionary potential. A phylogenetic tree is usually reconstructed by using the alignment of DNA sequences. However, with the availability of megatrees, subsetting with a list of species of concern is possible. Here we reconstructed a list of 53 Alocasia spp. (Araceae) from Indonesia and adjacent regions using available megatrees and publicly available DNA sequences in the GenBank. The result showed placed and unplaced Alocasia spp. on the terminal nodes of reconstructed phylogenetic trees. The unplaced species show that publicly available DNA sequences are not yet available, therefore should be prioritized for sequencing. The placed species in the phylogeny could be used for conservation prioritization of these Alocasia spp. Keywords: Alocasia, Indonesia, Megatree, Phylogeny, Plant conservation
... The Araceae family consists of 107 genera with over 3,700 species distributed worldwide (Erlinawati, 2010). The largest genera in the family are the Alocasia, which currently comprises 113 species with 27 species are still awaiting descriptions (Nauheimer et al., 2012). Of the total 96 accepted names of Alocasia species (GBIF, 2019), 79 species are reported as native to tropical and subtropical Asia, which extend from the subtropical eastern Himalayas throughout India, China, Japan, and across the Malay Archipelago until Oceania (Nauheimer et al., 2012;Ngoc-Sâm et al., 2017;Das, 2018;Ma et al., 2020). ...
... The largest genera in the family are the Alocasia, which currently comprises 113 species with 27 species are still awaiting descriptions (Nauheimer et al., 2012). Of the total 96 accepted names of Alocasia species (GBIF, 2019), 79 species are reported as native to tropical and subtropical Asia, which extend from the subtropical eastern Himalayas throughout India, China, Japan, and across the Malay Archipelago until Oceania (Nauheimer et al., 2012;Ngoc-Sâm et al., 2017;Das, 2018;Ma et al., 2020). The genus Alocasia features tropical plants with large, often showy leaves, which are generally referred to as Elephant's ear (Ongpoy, 2015;Yuliana & Fatmawati, 2018). ...
... G. Don (Chinese taro), an Asian plant of ethnobotanical importance and A. macrorrhizos (Lour.) G. Don (Giant taro), a tropical ornamental plant cultivated for its tubers and leaves, which is also used as animal fodder (Nauheimer et al., 2012). Besides being an ornamental plant, the genus Alocasia is traditionally used to treat several diseases including diarrhoea, constipation, diabetes, and cancer. ...
The genus Alocasia (Schott) G. Don consists of 113 species distributed across Asia, Southeast Asia, and Australia. Alocasia plants grow in tropical and subtropical forests with humid lowlands. Featuring their large green heart-shaped or arrow-shaped ear leaves and occasionally red-orange fruit, they are very popular ornamental plants and are widely used as traditional medicines to treat various diseases such as jaundice, snake bite, boils, and diabetes. This manuscript critically analysed the distribution, traditional uses, and phytochemical contents of 96 species of Alocasia. The numerous biological activities of Alocasia species were also presented, which include anti-cancer, antidiabetic and antihyperglycaemic, antioxidant, antidiarrhoea, antimicrobial and antifungal, antiparasitic (antiprotozoal and anthelminthic), antinociceptive and anti-inflammatory, brine shrimp lethality, hepatoprotective, anti-hemagglutinin, anti-constipation and diuretic, and radioprotective activities as well as acute toxicity studies. Research articles were acquired by the accessing three scientific databases comprising PubMed, Scopus, and Google Scholar. For this review, specific information was obtained using the general search term “Alocasia”, followed by the “plant species names” and “phytochemical” or “bioactivity” or “pharmacological activity”. The accepted authority of the plant species was referred from theplantlist.org. Scientific studies have revealed that the genus is mainly scattered throughout Asia. It has broad traditional benefits, which have been associated with various biological properties such as cytotoxic, antihyperglycaemic, antimicrobial, and anti-inflammatory. Alocasia species exhibit diverse biological activities that are very useful for medical treatment. The genus Alocasia was reported to be able to produce a strong and high-quality anti-cancer compound, namely alocasgenoside B, although information on this compound is currently limited. Therefore, it is strongly recommended to further explore the relevant use of natural compounds present in the genus Alocasia, particularly as an anti-cancer agent. With only a few Alocasia species that have been scientifically studied so far, more attention and effort is required to establish the link between traditional uses, active compounds, and pharmacological activities of various species of this genus.
... The quarternary cycles of glacial and interglacial events together with related changes in the climate affected the sea levels, island connectivity, species occurrences, and contractions and expansions in vegetation ranges (Woodruff, 2010;Cannon, 2012;Morley, 2012). Several phylogenetic and biogeographical studies of Malesian plant taxa assumed the three main biogeographic origins of Malesian lineages: (i) Eurasia, with colonization via continental Southeast Asia, for example, numerous taxa of boreotropical origin (Morley, 2003;Li et al., 2017;Zhou et al., 2019;Atkins et al., 2020;Yu & van Welzen, 2020), or via the mountain ranges of Taiwan Island and the Philippines (van Steenis, 1964); (ii) Gondwanan origin via the rafting Indian fragment into continental Southeast Asia (Nauheimer et al., 2012;Thomas et al., 2012) or via migration along the Arabian and south Asian coasts (Sirichamorn et al., 2014;Chen et al., 2019); (iii) Australia, with colonization from the Australian continent (Morley, 2003;Barker et al., 2007). ...
... Each taxon was assigned presence in one or more biogeographical area(s) based on its extant distribution in nine geographic regions, based on a combination of geological information of Southeast Asia (Hall, 2002(Hall, , 2012, previous biogeographical studies (Nauheimer et al., 2012;Yu & Van Welzen, 2020;Atkins et al., 2020;Yu & Van Welzen, 2020), and current knowledge of species distributions and relationships in the Dissochaeteae (Maxwell, 1984;Kartonegoro & Veldkamp, 2013;Kartonegoro et al., 2018Kartonegoro et al., , 2019. The nine biogeographical areas are as follows: A = East Bhutan, Northeast India, and Northwest Myanmar; B = Indochina (incl. ...
... The most probably common migration route from Sundaland across Wallace's line is through Sulawesi or the Philippines to eastern Wallacea/New Guinea (Su & Saunders, 2009;Thomas et al., 2012a;Nauheimer et al., 2012, Buerki et al., 2016Chen et al., 2019;Atkins et al., 2020;Yu & van Welzen, 2020). Our biogeographical reconstructions of Dissochaeteae (Fig. 3) identified four dispersal events across Wallace's line from West Malesia to Wallacea and East Malesia. ...
The region of Tropical Southeast Asia and the Malay Archipelago is a very appealing area for research because of its outstanding biodiversity, being one of the most species‐rich areas in the world with high levels of endemism, and because of its complex geological history. The high number of species in tribe Dissochaeteae (Melastomataceae) and their tendency to narrow endemism makes the tribe an ideal group for examining biogeographic patterns. We sampled 58 accessions spread over 42 accepted and two undescribed species of the Dissochaeteae. Two nuclear (ETS, ITS) and four chloroplast regions (ndhF, psbK‐psbL, rbcL, rpl16) were used for divergence time estimation and ancestral area reconstruction. Results from the molecular dating analysis suggest that the diversity of Dissochaeteae in the Southeast Asian region resulted from a South American ancestor in the late Eocene. The ancestor of the Dissochaeteae might have migrated from South America to Southeast Asia via North America and then entered Eurasia over the North Atlantic land bridge during the Eocene. The origin and early diversification of the Dissochaeteae in Southeast Asia dates back to the middle Oligocene, and most of the genera originated during the Miocene. Indochina and Borneo are most likely the area of origin for the most recent common ancestor of the Dissochaeteae and for many of the early diverging clades of some genera within Southeast Asia.
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... Hay 2000, Boyce 2007, Kurniawan et al. 2011, Nguyen et al. 2013, Wong et al. 2016, Van et al. 2017, Hamzah et al. 2017). This genus is mainly distributed in subtropical and tropical Asia, with extensions north to the Pan-Himalayas and south to northern Melanesia-Australasia (Nauheimer et al. 2012a). Systematic revisions on the genus Alocasia have been achieved much progress in Australasia (Hay & Wise 1991, Hay 1994, west Malesia and Sulawesi (Hay 1998, Yuzammi & Hay 1998, the Philippines (Hay 1999), Borneo (Hay 2000, Boyce 2007, Kurniawan & Boyce 2011, Lesser Sunda Islands (Kurniawan et al. 2013), Thailand (Boyce 2008) and Peninsular Malaysia (Zulhazman et al. 2017). ...
... Hitherto, eight Alocasia species have been reported for China (Li et al. 2010), though A. hypnosa J.T. Yin, Y.H.Wang & Z.F.Xu in Wang et al. (2005: 42) was split off as the monotypic genus Englerarum Nauheimer & Boyce (2013: 713) (Nauheimer et al. 2012a(Nauheimer et al. , 2012b(Nauheimer et al. , 2013, and the latest described A. lihengiae Long & Fang in Fang et al. (2020: 98) is rather dubious that would possibly be a synonym of E. hypnosum (J.T.Yin, Y.H.Wang & Z.F.Xu) Nauheimer & Boyce (2013: 713). Besides, morphological and molecular phylogenetic studies implied that the Chinese-distributed A. longiloba Miquel (1855: 207) complex needs to be further revised after comprehensive sampling in continental Asia including China to reach on better understanding on this species complex (Hay 1998, Nauheimer et al. 2012a). ...
... Hitherto, eight Alocasia species have been reported for China (Li et al. 2010), though A. hypnosa J.T. Yin, Y.H.Wang & Z.F.Xu in Wang et al. (2005: 42) was split off as the monotypic genus Englerarum Nauheimer & Boyce (2013: 713) (Nauheimer et al. 2012a(Nauheimer et al. , 2012b(Nauheimer et al. , 2013, and the latest described A. lihengiae Long & Fang in Fang et al. (2020: 98) is rather dubious that would possibly be a synonym of E. hypnosum (J.T.Yin, Y.H.Wang & Z.F.Xu) Nauheimer & Boyce (2013: 713). Besides, morphological and molecular phylogenetic studies implied that the Chinese-distributed A. longiloba Miquel (1855: 207) complex needs to be further revised after comprehensive sampling in continental Asia including China to reach on better understanding on this species complex (Hay 1998, Nauheimer et al. 2012a). ...
A new Alocasia species, Alocasia yunqiana, is described and compared with its morphologically related taxa. The novelty is characterized by an oblong-naviculiform-shaped spathe-limb that is strongly hooded and slightly glaucous to glossy during its entire anthesis, a spadix with a sterile interstice and an appendix that are much shorter and thinner than the staminate zone, as well as the dimorphic synandroidia. Detailed information containing description, colored plates and illustration are provided herein.
... Relatively few studies have attempted to reveal the exact migration route for plants across Wallace's line. The most common route between western and eastern Malesia is via the Philippines [Nauheimer, Boyce & Renner, 2012;Denduangboripant, Mendum & Cronk, 2001;Thomas et al., 2012;Jønsson et al., 2010 (birds)], but other routes have also been found, e.g. via Borneo and Sulawesi [Grudinski et al., 2014;Thomas et al., 2012;Evans et al., 2003 (frogs)] or between Java and the Lesser Sunda Islands (e.g. the route proposed by Su & Saunders, 2009, fig. ...
... Similar dispersals have been recorded in several case studies [e.g. Nauheimer et al., 2012, Thomas et al., 2012, Su & Saunders, 2009, Sheldon et al., 2012], but these mostly occurred < 12 Mya. Our results indicate that the exchange was already possible in an earlier time, probably up to the Early Miocene, when the Sulu Archipelago and Tawi-Tawi islands were already in place (Hall, 2009). ...
... The probably most commonly used migration route across Wallace's line is through the Philippines to eastern Wallacea/New Guinea (Nauheimer et al., 2012, Denduangboripant et al., 2001 or vice versa [e.g. Thomas et al., 2012, Su & Saunders, 2009, Jønsson et al., 2010]. ...
Trigonostemon and Dimorphocalyx are two morphologically similar genera in tropical Asia. We estimated their divergence times through a Bayesian clock analysis and reconstructed the historical biogeography using a likelihood analysis under the dispersal-extinction-cladogenesis (DEC) model and a statistical dispersal-vicariance analysis (S-DIVA). We have found that the two genera differ in their historical biogeography: Trigonostemon originated on the South-East Asian mainland, but one section dispersed to the Malay Peninsula and Borneo, where rapid speciation events occurred during the Pleistocene, whereas Dimorphocalyx originated on and extended to its current distribution from Borneo. The dispersal routes of both genera are well supported by the tectonic history and are comparable to the conclusions in previous case studies. Long-distance dispersals across Wallace’s line are of particular interest in biogeography. We compared the patterns of historical distribution and dispersal of our taxa and other comparable taxa in this area. Our data support the hypothesis that the Philippines is the most common stepping stone for crossing Wallace’s line. Furthermore, we consider that the frequent change of sea levels during the Pleistocene propelled the diversification of Trigonostemon section Trigonostemon in Borneo and the Malay Peninsula.
... The genus Colocasia comprises about 20 species distributed throughout Southeast Asia, six of which occur in China (Li et al. 2010). Recent studies suggest that Colocasia might be polyphyletic (Nauheimer et al. 2012b). According to molecular studies of Nauheimer et al. (2012b), Colocasia affinis is more closely related to Steudnera than to the species of Colocasia. ...
... Recent studies suggest that Colocasia might be polyphyletic (Nauheimer et al. 2012b). According to molecular studies of Nauheimer et al. (2012b), Colocasia affinis is more closely related to Steudnera than to the species of Colocasia. This close relationship is supported by different facts: (1) S. colocasiifolia and C. affinis share the same pollinator, (2) the epicuticular wax layer on the adaxial spathe blade in C. affinis resembles that of Steudnera spp., (3) C. affinis differs from other species of Colocasia through the absence of papillate epidermal cells and the temporary closure of the spathe during anthesis ). ...
... is plicate Ulrich, unpublished data) conforms the hypothesis by Nauheimer et al. (2012b). In this case the pollen characters are also useful for delimiting C. affinis from the other species of Colocasia. ...
This PhD-thesis gives insight into pollen morphology and ultrastructure of selected Araceae-species. New examples are provided for the significance of pollen characters in systematics as well as for the spathe as an osmophore. The present thesis demonstrates that the application of different preparation and staining methods as well as a combined analysis with light microscopy, scanning- and transmission electron microscopy are essential for the interpretation of pollen characters as well as for the study of floral organs related to pollination. Furthermore, this work shows that morphological studies of pollen grains are indispensable for the understanding of evolutionary processes and systematics. Four published studies are included and discussed. Six congress as well as seminar contributions are added as supplements. The thesis deals with the following three main topics:
1. Pollen morphology and ultrastructure of selected Araceae-species. — The genera of Araceae, also known as aroids, display a high morphological diversity, which extends to pollen wall morphology and exine sculpturing. In contrast to all other subfamilies of Araceae the pollen wall of Aroideae pollen lacks the common sporopollenin tectate-columellate exine. Instead, the outermost pollen wall layer consists of polysaccharides, which is a unique feature of some Aroideae pollen. The aim of this thesis is to give new insights into the pollen morphology and ultrastructure of selected Araceae species and to clarify contradicting literature reports. For this purpose, a total of 136 species (including 120 Aroideae) out of 69 genera (including 58 Aroideae) were investigated. The results of the investigated genus Amorphophllus and the schismatoglottid genera Apoballis and Schismattoglottis show that the pollen wall is exclusively made of polysaccharides. Moreover an additional thin surface layer, either polysaccharide or cuticula-like was detected. The investigation of Calla palustris tetrads in different developmental stages revealed that pollen is basically disulcate or with a ring-like aperture. Calla pollen is therefore extraordinary within the entire Araceae.
2. The significance of pollen characters in Araceae systematics. — One of the most important characters is the pollen wall, with its structural and ornamental features. In comparative pollen morphology and plant systematics pollen characters are at least as important as any other morphological character. The pollen characters of the investigated genera Apoballis, Schismattoglottis and Calla accord well with recent DNA-based phylogenies. Pollen characters, especially the aperture condition of Calla combined with other morphological and anatomical characters gives direction for a good placement of the controversial genus Calla within the Araceae.The results show that they are an excellent example for the significance of pollen characters in Araceae systematics.
3. Ultrastructure of osmophoric epidermal cells. — Many Araceae have floral traps to catch their pollinators. Several organs of the aroid inflorescence are involved in trapping. To attract pollinators, epidermal cells of the spathe or even of anthers are known to produce nectar or wax. To test the hypothesis of the spathe as an osmophore also the ultrastructure of secretory epidermal cells of different Colocasia species was investigated. Osmophoric epidermal cells in spathes are indicated by the prescence of numerous mitochondria, smooth endoplamatic reticulum, ribosomes, polyribosomes and vesicles that are transported through the cuticle. To proof the hypothesis, adaxial and abaxial parts of the spathe were investigated by transmissionelectronmicroscopy to find ultrastructural evidence for the synthesis of odors.The ultrastructural results as well as the morpho-anatomical results of the spathe epidermis indicate that it is an elaborate osmophore and serves for the emission of odours only.
... The genus Colocasia comprises about 20 species distributed throughout Southeast Asia, six of which occur in China (Li et al. 2010). Recent studies suggest that Colocasia might be polyphyletic (Nauheimer et al. 2012b). According to molecular studies of Nauheimer et al. (2012b), Colocasia affinis is more closely related to Steudnera than to the species of Colocasia. ...
... Recent studies suggest that Colocasia might be polyphyletic (Nauheimer et al. 2012b). According to molecular studies of Nauheimer et al. (2012b), Colocasia affinis is more closely related to Steudnera than to the species of Colocasia. This close relationship is supported by different facts: (1) S. colocasiifolia and C. affinis share the same pollinator, (2) the epicuticular wax layer on the adaxial spathe blade in C. affinis resembles that of Steudnera spp., (3) C. affinis differs from other species of Colocasia through the absence of papillate epidermal cells and the temporary closure of the spathe during anthesis ). ...
... is plicate Ulrich, unpublished data) conforms the hypothesis by Nauheimer et al. (2012b). In this case the pollen characters are also useful for delimiting C. affinis from the other species of Colocasia. ...
Pollen morphology and ultrastructure of selected Araceae species New examples for the significance of pollen characters in systematics and for the spathe as an osmophore verfasst von / submitted by Mag. Silvia Ulrich angestrebter akademischer Grad / in partial fulfilment of the requirements for the degree of Doktorin der Naturwissenschaften (Dr.rer.nat.) Wien, 2015 / Vienna 2015 Studienkennzahl lt. Studienblatt / degree programme code as it appears on the student record sheet: A 091 438
... The Alocasia-Colocasia clade comprises about 110 species diminutive geophytes to massive pachycaularborescent terrestrial or epilithic mesophytes, rather rarely helophytes, distributed from the subtropical eastern Himalayas throughout subtropical and tropical parts of Asia into the western pacific and eastern Australia. The most recent phylogenetic analyses of Araceae (Cusimano et al. 2011, Nauheimer et al. 2012a revealed Colocasieae (sensu Mayo et al. 1997) as a polyphyletic assemblage with Leucocasia gigantea (Blume 1823: 103) Schott (1857: 34) forming a well-supported separate clade along with Alocasia (Schott 1832: 18) G.Don in Sweet (1839: 631). Consequently the rank Colocasieae can no longer be used for the Alocasia-Colocasia clade since it lacks phylogenetic support. ...
... While Alocasiinae formally exists (Schott, 1856: 43) its rank is inappropriate and in any case its historical usage is incongruent with the retrieved phylogeny. Therefore we opt to use rankless Alocasia-Colocasia clade which includes the Colocasia clade (Cusimano et al. 2011, Nauheimer et al. 2012a with Alocasia and Leucocasia Schott (1857: 34) in the Alocasia clade. The Alocasia-Colocasia clade includes Alocasia, Ariopsis Nimmo in Graham (1839: 252), Colocasia, Englerarum Nauheimer & Boyce (2014: 713, epublished 2013, Leucocasia, Steudnera Koch (1862: 114), Remusatia Schott (1832: 18), and Vietnamocasia from this study. ...
... Although confident that these plants represented an undescribed species it remained unclear to which, if any, existing genus they should be assigned. To establish the generic position sequences were generated from three chloroplast loci, the trnL-F intergenic spacer, the rpl20-rps12 intergenic spacer, and the trnK/matK region, and one nuclear gene, phytochrome C (phyC), and analysed along with representative sequences of all genera of the Alocasia-Colocasia clade sensu Nauheimer et al. (2012a). The result of these analyses revealed that the plant represented a new genus as well as a new species of the Alocasia-Colocasia clade, here described as Vietnamocasia dauae N.S.Lý, S.Y.Wong, T.Haevermans & D.V.Nguyen. ...
Vietnamocasia, a new monotypic aroid genus in the Alocasia-Colocasia clade, is described with the type species, Vietnamo-casia dauae. Vietnamocasia is distinguished by possessing free individual staminate flowers, lacking expanded syncon-nectives, and having nodding inflorescences. Vegetatively Vietnamocasia is reminiscent of species of the distantly closely related Alocasia Cuprea Group, although Vietnamocasia is so far only known from the type locality in Central Vietnam, over 1200 km NE from the nearest representative of the Alocasia Cuprea Group. The phylogenetic analyses of Vietnamocasia da-uae together with representative taxa from all genera of the Alocasia-Colocasia clade recovered Vietnamocasia as a strongly supported clade sister to Alocasia, together nested in a clade to which Leucocasia is a sister taxon. Vietnamocasia dauae is illustrated from living plants and with a line drawing. A key to all genera of Alocasia-Colocasia clade is included.
... The Alocasia-Colocasia clade comprises about 110 species diminutive geophytes to massive pachycaularborescent terrestrial or epilithic mesophytes, rather rarely helophytes, distributed from the subtropical eastern Himalayas throughout subtropical and tropical parts of Asia into the western pacific and eastern Australia. The most recent phylogenetic analyses of Araceae (Cusimano et al. 2011, Nauheimer et al. 2012a revealed Colocasieae (sensu Mayo et al. 1997) as a polyphyletic assemblage with Leucocasia gigantea (Blume 1823: 103) Schott (1857: 34) forming a well-supported separate clade along with Alocasia (Schott 1832: 18) G.Don in Sweet (1839: 631). Consequently the rank Colocasieae can no longer be used for the Alocasia-Colocasia clade since it lacks phylogenetic support. ...
... While Alocasiinae formally exists (Schott, 1856: 43) its rank is inappropriate and in any case its historical usage is incongruent with the retrieved phylogeny. Therefore we opt to use rankless Alocasia-Colocasia clade which includes the Colocasia clade (Cusimano et al. 2011, Nauheimer et al. 2012a with Alocasia and Leucocasia Schott (1857: 34) in the Alocasia clade. The Alocasia-Colocasia clade includes Alocasia, Ariopsis Nimmo in Graham (1839: 252), Colocasia, Englerarum Nauheimer & Boyce (2014: 713, epublished 2013, Leucocasia, Steudnera Koch (1862: 114), Remusatia Schott (1832: 18), and Vietnamocasia from this study. ...
... Although confident that these plants represented an undescribed species it remained unclear to which, if any, existing genus they should be assigned. To establish the generic position sequences were generated from three chloroplast loci, the trnL-F intergenic spacer, the rpl20-rps12 intergenic spacer, and the trnK/matK region, and one nuclear gene, phytochrome C (phyC), and analysed along with representative sequences of all genera of the Alocasia-Colocasia clade sensu Nauheimer et al. (2012a). The result of these analyses revealed that the plant represented a new genus as well as a new species of the Alocasia-Colocasia clade, here described as Vietnamocasia dauae N.S.Lý, S.Y.Wong, T.Haevermans & D.V.Nguyen. ...
Vietnamocasia, a new monotypic aroid genus in the Alocasia-Colocasia clade, is described with the type species, Vietnamo-casia dauae. Vietnamocasia is distinguished by possessing free individual staminate flowers, lacking expanded syncon-nectives, and having nodding inflorescences. Vegetatively Vietnamocasia is reminiscent of species of the distantly closely related Alocasia Cuprea Group, although Vietnamocasia is so far only known from the type locality in Central Vietnam, over 1200 km NE from the nearest representative of the Alocasia Cuprea Group. The phylogenetic analyses of Vietnamocasia da-uae together with representative taxa from all genera of the Alocasia-Colocasia clade recovered Vietnamocasia as a strongly supported clade sister to Alocasia, together nested in a clade to which Leucocasia is a sister taxon. Vietnamocasia dauae is illustrated from living plants and with a line drawing. A key to all genera of Alocasia-Colocasia clade is included.
... The genus Alocasia (Schott) G. Don belongs to the family Araceae, and constitutes of over 113 species [21] of herbaceous, laticiferous, diminutive to gigantic, usually robust herbs. The genus is distributed from the subtropical eastern Himalayas throughout subtropical and tropical Asia into the tropical western pacific and eastern Australia [15,21]. ...
... The genus Alocasia (Schott) G. Don belongs to the family Araceae, and constitutes of over 113 species [21] of herbaceous, laticiferous, diminutive to gigantic, usually robust herbs. The genus is distributed from the subtropical eastern Himalayas throughout subtropical and tropical Asia into the tropical western pacific and eastern Australia [15,21]. Ten species of Alocasia are reported to be occurring in Thailand [4]. ...
Karyomorphological details of three species of the genus Alocasia native to Thailand are presented. The somatic number and karyotypic details of the three species are: Alocasia cucullata, 2n (28) = 22m + 6sm; A. longiloba, 2n (58) = 38m + 18sm + 2a; and A. macrorrhizos, 2n (28) = 20m + 8sm. The karyotype of A. longiloba and A. macrorrhizos are first record of these species. Satellite was observed only in karyotype of A. cucullatais reported.
... The genus Alocasia (Schott) G. Don belongs to the family Araceae, and constitutes of over 113 species [21] of herbaceous, laticiferous, diminutive to gigantic, usually robust herbs. The genus is distributed from the subtropical eastern Himalayas throughout subtropical and tropical Asia into the tropical western pacific and eastern Australia [15,21]. ...
... The genus Alocasia (Schott) G. Don belongs to the family Araceae, and constitutes of over 113 species [21] of herbaceous, laticiferous, diminutive to gigantic, usually robust herbs. The genus is distributed from the subtropical eastern Himalayas throughout subtropical and tropical Asia into the tropical western pacific and eastern Australia [15,21]. Ten species of Alocasia are reported to be occurring in Thailand [4]. ...
Karyomorphological details of three species of the genus Alocasia native to Thailand are presented. The somatic number and karyotypic details of the three species are: Alocasia cucullata, 2n (28) = 22m + 6sm; A. longiloba, 2n (58) = 38m + 18sm + 2a; and A. macrorrhizos, 2n (28) = 20m + 8sm. The karyotype of A. longiloba and A. macrorrhizos are first record of these spe-cies. Satellite was observed only in karyotype of A. cucullatais reported.
... Within Southeast Asia, certain regions may have higher rates of endemism and diversification. For example, de Bruyn et al. (2014) recently identified Borneo and Indochina as 'evolutionary hotspots' in a phylogenetic meta-analysis of both flora and fauna, and several studies cite Borneo as the centre of diversification for multiple taxa (Nauheimer et al., 2012;Webb and Ree, 2012). ...
... While the barrier to crossing Wallace's line has proved to be a hindrance for the dispersal in many faunal groups, it is less so among plants (Van Welzen et al., 2011). Other examples of an inferred origin of flora in Borneo and subsequent dispersal across Wallace's line during the Miocene include Rhododendronsection Vireya (Ericaceae) (Brown et al., 2006;Webb and Ree, 2012), Alocasia (Araceae) (Nauheimer et al., 2012) and Begonia (Thomas et al., 2012). Finally, the dispersal of two taxa native to the Western Ghats of India may be the result of overland or overwater dispersal. ...
Background and aims:
The breadfruit genus ( Artocarpus , Moraceae) includes valuable underutilized fruit tree crops with a centre of diversity in Southeast Asia. It belongs to the monophyletic tribe Artocarpeae, whose only other members include two small neotropical genera. This study aimed to reconstruct the phylogeny, estimate divergence dates and infer ancestral ranges of Artocarpeae, especially Artocarpus , to better understand spatial and temporal evolutionary relationships and dispersal patterns in a geologically complex region.
Methods:
To investigate the phylogeny and biogeography of Artocarpeae, this study used Bayesian and maximum likelihood approaches to analyze DNA sequences from six plastid and two nuclear regions from 75% of Artocarpus species, both neotropical Artocarpeae genera, and members of all other Moraceae tribes. Six fossil-based calibrations within the Moraceae family were used to infer divergence times. Ancestral areas and estimated dispersal events were also inferred.
Key results:
Artocarpeae, Artocarpus and four monophyletic Artocarpus subgenera were well supported. A late Cretaceous origin of the Artocarpeae tribe in the Americas is inferred, followed by Eocene radiation of Artocarpus in Asia, with the greatest diversification occurring during the Miocene. Borneo is reconstructed as the ancestral range of Artocarpus , with dozens of independent in situ diversification events inferred there, as well as dispersal events to other regions of Southeast Asia. Dispersal pathways of Artocarpus and its ancestors are proposed.
Conclusions:
Borneo was central in the diversification of the genus Artocarpus and probably served as the centre from which species dispersed and diversified in several directions. The greatest amount of diversification is inferred to have occurred during the Miocene, when sea levels fluctuated and land connections frequently existed between Borneo, mainland Asia, Sumatra and Java. Many species found in these areas have extant overlapping ranges, suggesting that sympatric speciation may have occurred. By contrast, Artocarpus diversity east of Borneo (where many of the islands have no historical connections to the landmasses of the Sunda and Sahul shelves) is unique and probably the product of over water long-distance dispersal events and subsequent diversification in allopatry. This work represents the most comprehensive Artocarpus phylogeny and biogeography study to date and supports Borneo as an evolutionary biodiversity hotspot.
... Alocasia comprises about 100 species of mainly understory herbs from humid evergreen tropical and subtropical forest in Asia and Australia (Boyce 2007(Boyce , 2008Hay 1998Hay , 1999Hay , 2000Hay & Wise 1991;Kurniawan & Boyce 2011;Medecilo et al. 2007;Nauheimer et al. 2012). The latest monograph for Alocasia of West Malesia and Sulawesi is Hay (1998), since when several additional species have been described from Borneo (Hay 2000;Boyce 2007Boyce , 2008Kurniawan & Boyce 2011). ...
... The latest monograph for Alocasia of West Malesia and Sulawesi is Hay (1998), since when several additional species have been described from Borneo (Hay 2000;Boyce 2007Boyce , 2008Kurniawan & Boyce 2011). A recent phylogeny of Alocasia by Nauheimer et al. (2012) suggested several dispersal events leading to speciation in Malesia, and revealed that Alocasia and Leucocasia (formerly Colocasia) gigantea (Blume) Schott formed a lineage separate from the rest of the Colocasieae sensu Mayo et al. (1997). Hay (1998) records only one Alocasia species for the Lesser Sunda Islands, the widespread cultivated/feral and certainly non-indigenous A. macrorrhizos (L.) G.Don. ...
Alocasia alba Schott is a new record for the islands of Bali and Lombok, in the Indonesian Lesser Sunda Islands. An expanded description is given, and the species illustrated from living plants. A key to species of Alocasia for the Lesser Sunda Islands is provided.
... Colocasia yunnanensis is another new species differentiated from C. bicolor due to a sterile zone with white hairs in the inflorescence and a spadix without an appendix (Xiuzhen et al. 2006) which is a highly variable trait among C. esculenta cultivars. Although C. gigantea was thought to be closely related to C. esculenta, chloroplastic DNA analyses have shown that it is in fact closer to Alocasia (Nauheimer et al. 2012;Ahmed et al. 2013). It is difficult to consider C. formosana as a different species but, since C. esculenta is poorly defined, it is difficult to reject it. ...
Despite its essential role for food security, vast geographical distribution, high nutritional value, and considerable trade, very few improved genotypes of taro (Colocasia esculenta (L.) Schott) are available to farmers. This review present an update on taro’s origin, wild relatives, domestication, diversity, preservation of germplasm, breeding history, objectives, methods and breeding strategies. Poor flowering of cultivars is the main factor limiting hybridization. For decades, it was thought that cultivars were sterile and could not produce seeds due to high ploidy or mutations inhibiting their sexuality. Taro diversity has been explored with different molecular markers, with no congruence between morphological and molecular groupings. Poor correlations between traits measured in seminal and first clonal generation, as well as heterogeneity of planting material, affect accurate phenotyping and slow down breeding cycles. Most efforts have been oriented towards taro leaf blight tolerance. The high diversity found within the pathogen (Phytophtora colocasiae Raciborski) favours the development of horizontal resistance. Breeding programs achievements have been constrained by: (i) Limited project funds oriented towards the development of expensive molecular tools rather than breeding activities, (ii) Absence of long-term commitments from research institutions, and (iii) Poor international cooperation. Encouraging results have been obtained through the exchange of germplasm and will pave the way to future breeding developments, long overdue to farmers, especially in Africa. Future directions to assist breeders are outlined and discussed.
... Colocasia is a genus of flowering plants in the family Araceae, native to southeastern Asia and Indian subcontinent [1]. It grows best in the sandy loam or alluvial soil with abundant organic matter and moisture holding capacity. ...
Colocasia Esculenta leaves are well known for water repellency and antifog features. Present invention deals with development of a water repellant surface coat over the selective substrates using the Colocasia Esculenta leaf slurry. Slurry of leaf alone and its combination with a water-based paint was used as a surface applicant. Specific qualitative tests (adhesion and abrasion resistivity) and essential supportive tests (density, pH and microbial growth) were conducted on the coated surface alongside for the additive added to the surface applicant. In the present study an efficient surface applicant with enhanced adhesion, abrasion resistance and effective water repellency was developed successfully.
... Despite the absence of volcanoes, Borneo has a lot of substrate variations which are important in biodiversity evolution (de Bruyn et al. 2014;Yu et al. 2021). Borneo was considered by several studies as the center of diversification for multiple taxa (Nauheimer et al. 2012;Webb and Ree 2012) including the genus Artocarpus, making it an evolutionary biodiversity hotspot (Williams et al. 2017). Southeast Asian forests can be characterized by the ubiquity of Dipterocarpaceae (Aoyagi et al. 2012;Heckenhauer et al. 2018;Raes et al. 2014). ...
Setiawan AW, Tjiu A, Meididit A, Iswinanto, Ginanjar A, Atut Y, Agusti R. 2021. Plant diversity in logged over forest in Mahakam Ulu, East Kalimantan, Indonesia. Biodiversitas 22: 4829-4838. A study of flora was conducted in the Ratah Timber concession area. The objectives of this study were to calculate the Importance Value Index (IVI) and identify species diversity in Mahakam Ulu, East Kalimantan. A survey was carried out in 128 plots within 13 transects placed purposively. Vegetation sampling was conducted using line-transect and a quadrat method. As many as 530 species belonging to 79 families were found. Of these species, 420 species were found in observation plots with 374 of the species being trees. The most dominant tree species were Endertia spectabilis, Shorea pinanga and Shorea leprosula with IVI of 10.24%, 8.25%, and 6.96%, respectively. In total, 114 species or 21.5% are endemic species of Borneo. The Shannon-Wiener diversity index at tree level was 5.51 and at seedling level was 4.95. The highest Similarity Index was found between transects 23 and 21, meanwhile the lowest was between transects 05 and 15. This study found 61 species that are classified on the International Union for Conservation of Nature (IUCN) Red List (2020-1) as critically endangered (16), endangered (11), and vulnerable (34) species.
... The early and middle Miocene epoch was wet and warm, with rainforest across Sundaland [20]. Southward migration from continental Asia to Sundaland during the Miocene period has been documented for many plant species, e.g., Lithocarpus (Fagaceae) [21], Pseuduvaria (Annonaceae) [22], Begonia (Begoniaceae) [23], and Alocasia (Araceae) [24]. A decline in the sea level enabled a periodic exchange of organisms between regions that were otherwise isolated. ...
The phylogeny of the genus Paphiopedilum based on the plastome is consistent with morphological analysis. However, to date, none of the analyzed nuclear markers has confirmed this. Topology incongruence among the trees of different nuclear markers concerns entire sections of the subgenus Paphiopedilum. The low-copy nuclear protein-coding gene PHYC was obtained for 22 species representing all sections and subgenera of Paphiopedilum. The nuclear-based phylogeny is supported by morphological characteristics and plastid data analysis. We assumed that an incongruence in nuclear gene trees is caused by ancestral homoploid hybridization. We present a model for inferring the phylogeny of the species despite the incongruence of the different tree topologies. Our analysis, based on six low-copy nuclear genes, is congruent with plastome phylogeny and has been confirmed by phylogenetic network analysis.
... As a result, the uplift of the QTP has created young endemic 'plant cradles' in the Hengduan Mountains, which act as an 'evolutionary front' in China (Lopez-Pujol et al., 2011). However, the origin and evolution of many montane species (e.g., Incarvillea spp.) and the biogeographical patterns (e.g., dispersal routes) between the mountainous hotspots of Central Asia have yet to be fully studied; therefore, understanding the causes and consequences of these patterns remains a challenge (e.g., Nauheimer et al., 2012). ...
The complex orogeny of the Himalaya and the Qinghai-Tibet Plateau (QTP) fosters habitat fragmentation that drives morphological differentiation of mountain plant species. Consequently, determining phylogenetic relationships between plant subgenera using morphological characters is unreliable. Therefore, we used both molecular phylogeny and historical biogeographic analysis to infer the ancestral states of several vegetative and reproductive characters of the montane genus Incarvillea. We determined the taxonomic position of the genus Incarvillea within its family and inferred the biogeographical origin of taxa through Bayesian inference (BI), maximum likelihood (ML) and maximum parsimony (MP) analyses of three molecular data sets (trnL-trnF sequences, ITS sequences, and a data set of combined sequences) derived from 81% of the total species of the genus Incarvillea. Within the genus-level phylogenetic framework, we examined the character evolution of 10 key morphological characters, and inferred the ancestral area and biogeographical history of the genus. Our analyses revealed that the genus Incarvillea is monophyletic and originated in Central Asia during mid-Oligocene ca. 29.42 Ma. The earliest diverging lineages were subsequently split into the Western Himalaya and Sino-Himalaya during the early Miocene ca. 21.12 Ma. These lineages resulted in five re-circumscribed subgenera (Amphicome, Olgaea, Niedzwedzkia, Incarvillea, and Pteroscleris). Moreover, character mapping revealed the ancestral character states of the genus Incarvillea (e.g., suffruticose habit, cylindrical capsule shape, subligneous capsule texture, absence of capsule wing, and loculicidal capsule dehiscence) that are retained at the earliest diverging ancestral nodes across the genus. Our phylogenetic tree of the genus Incarvillea differs from previously proposed phylogenies; we recommend placing the subgenus Niedzwedzkia close to subgenus Incarvillea and maintaining two main divergent lineages.
... The geography of these six evolutionary hotspots was the most complex area in tectonic history, formed by the interaction of Indian, Eurasian, Australian and Pacific Plates (Hall and Spakman 2015). Therefore, the highly fragmented islands and limestone landscapes in Southeast Asia probably facilitated speciation of the Asian Gesneriaceae, similar pattern found in Begonia (Chung et al. 2014) and Alocasia (Nauheimer et al. 2012). Burtt (1998) proposed that Gesneriaceae is of southern hemisphere (Gondwana) origin, with the Gondwana broken down and dispersed all over the world. ...
Based on an updated taxonomy of Gesneriaceae, the biogeography and evolution of the Asian Gesneriaceae are outlined and discussed. Most of the Asian Gesneriaceae belongs to Didymocarpoideae, except Titanotrichum was recently moved into Gesnerioideae. Most basal taxa of the Asian Gesneriaceae are found in the Indian subcontinent and Indo-China Peninsula, suggesting Didymocarpoideae might originate in these regions. Four species diversification centers were recognized, i.e. Sino-Vietnam regions, Malay Peninsula, North Borneo and Northwest Yunnan (Hengduan Mountains). The first three regions are dominated by limestone landscapes, while the Northwest Yunnan is well-known for its numerous deep gorges and high mountains. The places with at least 25% species are neoendemics (newly evolved and narrowly endemic) which were determined as evolutionary hotspots, including Hengduan Mountains, boundary areas of Yunnan-Guizhou-Guangxi in Southwest China, North Borneo, Pahang and Terengganu in Malay Peninsula, and mountainous areas in North Thailand, North Sulawesi Island. Finally, the underlying mechanisms for biogeographical patterns and species diversification of the Asian Gesneriaceae are discussed.
... Hence, Borneo is a suitable natural laboratory for tropical evolutionary biology studies. Most of the studies of Borneo taxa have shown that Borneo was already a major evolutionary hotspot and centre of divergence in the pre-Miocene (see review by De Bruyn et al. (2014)) or pre-Pliocene (Nauheimer, Boyce & Renner, 2012;Klaus et al., 2013;De Bruyn et al., 2014;Grismer et al., 2016;Williams et al., 2017;Chua et al., 2017;Chen et al., 2018). In addition, previous studies suggest that contemporary biodiversity richness and distribution patterns have been affected by climatic fluctuations in the Pleistocene (Barkman & Simpson, 2001;Quek et al., 2007;Jalil et al., 2008;Patou et al., 2010;Lim et al., 2010;Lim & Sheldon, 2011;Ueda et al., 2010). ...
Borneo has gone through dramatic changes in geology and topography from the early Eocene until the early Pliocene and experienced climatic cycling during the Pleistocene. However, how these changes have shaped the present-day patterns of high diversity and complex distribution are still poorly understood. In this study, we use integrative approaches by estimating phylogenetic relationships, divergence time, and current and past niche suitability for the Bornean endemic land snail genus Everettia to provide additional insight into the evolutionary history of this genus in northern Borneo in the light of the geological vicariance events and climatic fluctuations in the Pleistocene. Our results show that northern Borneo Everettia species belong to two deeply divergent lineages: one contains the species that inhabit high elevation at the central mountain range, while the other contains lowland species. Species diversification in these lineages has taken place before the Pliocene. Climate changes during the Pleistocene did not play a significant role in species diversification but could have shaped contemporary species distribution patterns. Our results also show that the species-rich highland habitats have acted as interglacial refugia for highland species. This study of a relatively sedentary invertebrate supports and enhances the growing understanding of the evolutionary history of Borneo. Species diversification in Everettia is caused by geological vicariance events between the early Miocene and the Pliocene, and the distribution patterns were subsequently determined by climatic fluctuations in the Pleistocene.
... Alocasia (Schott in Schott & Endlicher 1832: 18), as one of the largest genera in the family Araceae, is mainly distributed in tropical and subtropical Asia, with a natural range that extends from the subtropical eastern Himalayas throughout India, China, Japan, to the Malay Archipelago and Oceania (Nauheimer et al. 2012). It is a genus of herbaceous, laticiferous, diminutive geophytes to massive pachycaul arborescent terrestrial or epilithic mesophytes, rather rarely helophytes (Ly et al. 2017), usually robust herbs (Boyce 2008). ...
Alocasia, a new species of Araceae from Jinuo Mountains, Yunnan, China is described and illustrated. The new species is similar to A. odora and A. hypnosa but differs from A. odora by purple-pink spathe and seasonally dormant habit, while differs from A. hypnosa by leaf blade with upwards basal lobes, milky yellow spadix and persistent purple-black stigma. The new species is terrestrial and grows in open roadside karst area.
... Distribución: Género con alrededor de 113 especies distribuidas en el sudeste de Asia, la región de Malasia y Australia (Nauheimer, Boyce y Renner, 2012). En Colombia se introdujo la especie Alocasia macrorrhizos (L.) G. Don (Zuluaga, Jácome y Croat, 2015), la cual ha sido registrada en Bogotá y se encuentra presente en las colecciones vivas del Jardín Botánico de Bogotá. ...
A través de los años el Jardín Botánico de Bogotá ha realizado numerosos esfuerzos para la publicación de guías de campo tratando algunos grupos de plantas, colecciones o áreas específicas de las colecciones vivas del Jardín. Entre estas, solo para mencionar algunas, se elaboró la Guía ilustrativa de las colecciones especializadas para la
conservación (CEPAC) (Santos, Fernández y Sarmiento, 2009), la Guía de las especies amenazadas presentes en las colecciones vivas del Jardín, las Criptógamas del Jardín Botánico José Celestino Mutis, musgos, helechos y plantas afines, la Guía de plantas acuáticas del Jardín de humedales y Las Orquídeas del Jardín Botánico José Celestino Mutis. El Jardín también ha publicado algunas guías destinadas a ayudar al público a recorrer sus colecciones, tales como la guía para el visitante
(Jardín Botánico de Bogotá, 2009) y la Guía didáctica del Jardín
introductorio o glosológico. Bajo este escenario, la Guía de géneros de angiospermas y gimnospermas del Jardín Botánico de Bogotá se enriqueció con los trabajos previos y se concibió como un producto que
pudiera articular y complementar dichos esfuerzos. La presente guía trata las plantas espermatófitas, es decir aquellas que producen semilla, incluyendo gimnospermas y angiospermas, las cuales no habían sido abordadas de forma general con anterioridad y que paradójicamente representan el grueso de las plantas existentes en las colecciones vivas del Jardín.
La guía está enfocada a nivel de género. Las plantas vivas del Jardín ascienden a cerca de 51.204 individuos pertenecientes a 1027 especies, 626 géneros y 179 familias; 75 de las especies en el Jardín presentan alguna categoría de amenaza, 31 en categoría vulnerable, 30 en peligro y 14 en peligro crítico. En un escenario ideal se esperaría tener representadas en la guía todos los géneros y especies que crecen en el Jardín, pero este sería un trabajo monumental, muy extenso para un
solo abordaje; sin embargo, esta tarea queda abierta a ser completada en posteriores esfuerzos.
En la presente guía se optó por tomar una muestra representativa de la gran diversidad de plantas existentes en el Jardín y por ello fueron seleccionados 200 géneros de los más abundantes y llamativos de las colecciones vivas. Se incluyeron tanto géneros nativos del área de Bogotá como también aquellos de presencia común en jardines y zonas
verdes, en su mayoría de origen exótico. Algunas plantas de interés evolutivo o por considerarse rarezas también fueron incluidas, varias de ellas solo pueden ser observadas en Bogotá en las colecciones vivas del Jardín, tal es el caso de los géneros Ginkgo y Banksia. También se incluyeron algunos géneros importantes para conservación ex situ y para los cuales algunas de sus especies se encuentran en riesgo de extinción,
tal fue el caso de Quercus, Colombobalanus, Cedrela, Polylepis y Ceroxylon. Como un valor agregado muchas de las especies fotografiadas para la guía fueron colectadas, identificadas e
ingresadas al herbario JBB. Los especímenes de herbario pueden ser consultados en físico en las instalaciones del Jardín u online en su plataforma web.
La guía se encuentra organizada en cuatro partes: un corto capítulo introductorio, donde se hace una reseña sobre la organización de las colecciones vivas y se incluye un mapa general del Jardín para ayudar con la ubicación de las plantas Maloca Área infantil (Foto: John Bernal)
en las colecciones. Luego se presenta información básica sobre la morfología de las gimnospermas y las angiospermas, para posteriormente explicar cómo debe ser usada la guía y cómo se estructura cada una de las fichas de géneros incluidas. La segunda parte incluye el cuerpo principal de la guía donde se incluyen claves para ayudar en la identificación de los géneros y se relacionan las fichas de los 200 géneros, organizadas en orden alfabético por familias, y dentro de cada una, en orden alfabético por géneros. Posteriormente se presenta una bibliografía minuciosa para quien quiera ahondar más en alguno de los géneros tratados y finalmente se presenta un glosario ilustrado en el que se encuentra un compendio de los términos botánicos que consideramos podrían requerir una definición explícita para el lector.
... Discordance between plastid and nuclear phylogenies has been found to have been caused by hybridisation and subsequent chloroplast capture in angiosperms (e.g. Rieseberg and Soltis 1991;Pelser et al. 2010;Nauheimer et al. 2012;Guo et al. 2018). Although reticulation is common in plants, multiple evolutionary scenarios can lead to incongruences between gene trees, including gene duplication, horizontal gene transfer and incomplete lineage sorting (Degnan and Rosenberg 2009). ...
Nepenthes is a genus of carnivorous plants consisting of ~160 species that are distributed in the paleotropics. Molecular systematics has so far not been able to resolve evolutionary relationships of most species because of the limited genetic divergence in previous studies. In the present study, we used a genome-skimming approach to infer phylogenetic relationships on the basis of 81 plastid genes and the highly repetitive rRNA (external transcribed spacer (ETS)–26S) for 39 accessions representing 34 species from eight sections. Maximum-likelihood analysis and Bayesian inference were performed separately for the nuclear and the plastid datasets. Divergence-time estimations were conducted on the basis of a relaxed molecular-clock model, using secondary calibration points. The phylogenetic analyses of the nuclear and plastid datasets yielded well resolved and supported phylogenies. Incongruences between the two datasets were detected, suggesting multiple hybridisation events or incomplete lineage sorting in the deeper and more recent evolutionary history of the genus. The inclusion of several known and suspected hybrids in the phylogenetic analysis provided insights into their parentage. Divergence-time estimations placed the crown diversification of Nepenthes in the early Miocene, c. 20 million years ago. This study showed that genome skimming provides well resolved nuclear and plastid phylogenies that provide valuable insights into the complex evolutionary relationships of Nepenthes.
... Yet another interesting aspect of our phylogeny is the topological conflicts between the nuclear and plastid phylogenies even after the addition of several new species (see Jaramillo et al., 2008 for previous results). Several studies in angiosperm lineages have established this pattern where a nuclear tree is in agreement with the morphology based grouping where the chloroplast topologies is in accordance with its geographical distribution (Nauheimer et al., 2012;Rieseberg and Soltis 1991). Our analyses also support this view to a great extent; our nuclear phylogeny recovered the morphological and geographical grouping proposed in Piper, while the analysis of plastid data alone reflects a geographical structure (Fig. S2.3). ...
The evolution of Peninsular Indian biodiversity has been a fascinating topic of research due to historical connections of this region to the ancient Gondwanaland. We investigated the phylogeny and historical biogeography of nearly all extant species of the genus Piper reported from the region to assess the biogeographical origins and test mechanisms of lineage diversification (dispersal, vicariance and in situ radiation) of this highly diverse genus of angiosperms commonly found in the understory of evergreen forests. The phylogeny of 21 species of Piper reported from Peninsular India was reconstructed for the first time, which included three new putative species from the Western Ghats. We used BEAST for the divergence time estimations (using three constraints), and ancestral range estimations were performed with the dated phylogenetic tree using BIOGEOBEARS. Divergence dating analysis revealed that the genus Piper originated during lower Cretaceous around 110Ma [95% highest posterior density (HPD): 116-105 Ma] and colonized Peninsular India five times independently, from Southeast Asia starting from the Oligocene. The two major dispersals into India occurred during the periods of 27.3Ma (95% HPD: 35.8 - 19.9.) and 15.5Ma (95% HPD: 24.9 - 7.11). This was followed by rapid radiations in some lineages with subsequent back dispersals to Southeast Asia. Our study indicates that dispersals from Southeast Asia led to the arrival of Piper to Indian subcontinent following the Indo-Eurasian collision. Members of Piper have colonized and diversified within the climatically stable habitats of Peninsular India. Furthermore, the present study provides evidence for the Miocene overland dispersal of Piper species to Africa from South Asia.
... Alocasia commonly known as Elephant's Ears, is one of the most morphologically diverse genera of about 113 species in the aroid or Araceae family. It is distributed from Sri Lanka through Indochina to China, southern Japan, the Malesian region, Oceania and Australia (Nauheimer et al., 2012). This rhizomatous or bulbous perennial is a genus of major horticultural importance and agricultural significance in tropical and subtropical Asia due to its beautiful foliage, patterns of leaf variegation and texture (Medecilo & Madulid, 2013;Bhatt et al. 2013). ...
... Image of the Alocassia macrorhiza plant[28] ...
In this work, we reported preparation of the silver nanoparticles (Ag NPs) supported on natural diatomite surface as a cheap support using Alocasia macrorrhiza leaf extract. The existing phytochemicals in the A. macrorrhiza leaf extract converts the silver ions to Ag NPs on diatomite as a natural support. The green synthesized Ag/diatomite nanocomposite was characterized by using various analytical techniques such as FT-IR, XRD, FESEM, TEM, EDS. The synthesized Ag NPs were identified using FT-IR and UV–visible spectrophotometry. The Ag/diatomite nanocomposite was used as an effective nanocatalyst for the reduction of 4-nitrophenol (4-NP), 2,4-dinitrophenylhydrazine (2,4-DNPH), methyl orange (MO), Congo red (CR) and Nigrosin (NS) using sodium borohydride at ambient temperature. Furthermore, the Ag/diatomite nanocomposite can be recovered and reused five times without marked loss of its catalytic activity.
... Examples from several angiosperm lineages (e.g. Araceae 39 , Asteraceae 70 , Saxifragaceae 71 ) have long revealed conflicting patterns, in which the nuclear phylogeny is in accordance with morphology, whereas the plastid relationships correlate to geographical distributions. The nuclear-morphological and plastid-geographical phylogenetic relationship patterns recovered in Cycnoches follow this phenomenon, which might be associated to the genetic exchange promoted by seeds vs pollen. ...
The Andean uplift is one of the major orographic events in the New World and has impacted considerably the diversification of numerous Neotropical lineages. Despite its importance for biogeography, the specific role of mountain ranges as a dispersal barrier between South and Central American lowland plant lineages is still poorly understood. The swan orchids (Cycnoches) comprise ca 34 epiphytic species distributed in lowland and pre-montane forests of Central and South America. Here, we study the historical biogeography of Cycnoches to better understand the impact of the Andean uplift on the diversification of Neotropical lowland plant lineages. Using novel molecular sequences (five nuclear and plastid regions) and twelve biogeographic models, we infer that the most recent common ancestor of Cycnoches originated in Amazonia ca 5 Mya. The first colonization of Central America occurred from a direct migration event from Amazonia, and multiple bidirectional trans-Andean migrations between Amazonia and Central America took place subsequently. Notably, these rare biological exchanges occurred well after major mountain building periods. The Andes have limited plant migration, yet it has seldom allowed episodic gene exchange of lowland epiphyte lineages such as orchids with great potential for effortless dispersal because of the very light, anemochorous seeds. Neotropical landscape and biodiversity have long drawn the attention of naturalists 1, 2. The tropical Andes are of particular interest as the world's premier biodiversity hotspot, with both an extraordinary species richness and a remarkable level of endemism 3–5. The combination of molecular phylogenies with species distributions and the fossil record has uncovered different biotic and abiotic factors that fostered diversification in the Neotropics 6–10. Biogeographical studies applying modern phylogenetic methods on Neotropical plant clades (e.g. Begonia 11 ,
... In this study, we will confront the current understanding of leaf water isotopes patterns to high density maps of Colocasia esculenta leaves. This species is a monocot native to South East Asian tropical forests (Nauheimer et al. 2012) but has been cultivated across the world for many centuries under the common name of taro. Its leaves can easily reach a size of up to c. 80 cm in length and c. 60 cm in width (Ivancic & Lebot, 1999), making it a good candidate for high density sampling. ...
Spatial patterns of leaf water isotopes are challenging to predict because of the intricate link between vein and lamina water. Many models have attempted to predict these patterns, but to date most have focused on monocots with parallel veins. These provide a simple system to study, but do not represent the majority of plant species. Here, a new protocol is developed using a Picarro induction module coupled to a cavity ringdown spectrometer to obtain maps of the leaf water isotopes ((18) O and (2) H). The technique is applied to Colocasia esculenta leaves. The results are compared to isotope ratio mass spectrometry. In C. esculenta, a large enrichment in the radial direction is observed, but not in the longitudinal direction. The string-of-lakes model fails to predict the observed patterns, while the Farquhar-Gan model is more successful, especially when enrichment is accounted for along the radial direction. Our results show that reticulate veined leaves experience a larger enrichment along the axis of the secondary veins than along the midrib. We hypothesize that this is due to the lower major/minor vein ratio that leads to longer pathways between major veins and sites of evaporation.
... In contrast to traditional classifi cations, the most recent phylogenetic analyses of Araceae (Cusimano et al. 2011, Nauheimer et al. 2012a reveal Alocasia G. Don as not closely related to genera such as Colocasia Schott, but instead forming a well-supported separate clade with Leucocasia gigantea (Blume) Schott. Consequently Colocasieae (sensu Mayo et al. 1997) can no longer be used for the Colocasia -Alocasia alliance because it lacks phylogenetic support. ...
Alocasia farisii Zulhazman, Norzielawati & P. C. Boyce is described and illustrated from Karst limestone in Kelantan as the first recorded Peninsular Malaysian species of the hitherto wholly Bornean Alocasia princeps complex, within which A. farisii most closely resembles the southwest Sarawak limestone-obligated Alocasia reversa N. E. Br.
... The "west-to-east" dispersal was inferred from other plant taxa of different families, e.g., Pseuduvaria Miq. (Annonaceae) [72], Alocasia (Schott) G. Don (Araceae) [75], Begonia L. (Begoniaceae) [76] and tribe Millettieae (Fabaceae) [77]. This west-to-eastward dispersal is consistent with the geologic history of the region. ...
Aphananthe is a small genus of five species showing an intriguing amphi-Pacific distribution in eastern, southern and southeastern Asia, Australia, and Mexico, also with one species in Madagascar. The phylogenetic relationships of Aphananthe were reconstructed with two nuclear (ITS & ETS) and two plastid (psbA-trnH & trnL-trnF) regions. Clade divergence times were estimated with a Bayesian approach, and the ancestral areas were inferred using the dispersal-extinction-cladogenesis and Bayesian Binary MCMC analyses. Aphananthe was supported to be monophyletic, with the eastern Asian A. aspera resolved as sister to a clade of the remaining four species. Aphananthe was inferred to have originated in the Late Cretaceous (71.5 mya, with 95% HPD: 66.6–81.3 mya), and the crown age of the genus was dated to be in the early Miocene (19.1 mya, with 95% HPD: 12.4–28.9 mya). The fossil record indicates that Aphananthe was present in the high latitude thermophilic forests in the early Tertiary, and experienced extinctions from the middle Tertiary onwards. Aphananthe originated in Europe based on the inference that included fossil and extant species, but eastern Asia was estimated to be the ancestral area of the clade of the extant species of Aphananthe. Both the West Gondwanan vicariance hypothesis and the boreotropics hypothesis could be excluded as explanation for its amphi-Pacific distribution. Long-distance dispersals out of eastern Asia into North America, southern and southeastern Asia and Australia, and Madagascar during the Miocene account for its wide intercontinental disjunct distribution.
... Second, we used the GTR + G + I substitution model based on the result of AIC from Modeltest v.2.3 (Nylander, 2004) and an uncorrelated lognormal relaxed molecular clock model selected in BEAST v.1.7.5 (Drummond and Rambaut, 2007). We used six calibration points obtained from the literature: Alismatales crown node 128 Ma; Cymodoceae crown node 61 Ma, Zosteraceae crown node 17 Ma, Hydrocharitaceae crown node 75 Ma, and Tofieldiaceae crown node 100 Ma (Janssen and Bremer, 2004); and Alocasia crown node 19.28 Ma (Nauheimer et al., 2012). We then ran two replicates of the MCMC analyses in BEAST, each for 100 million generations, sampling every 1000 generations. ...
While our knowledge of species distributions and diversity in the terrestrial biosphere has increased sharply over the last decades, we lack equivalent knowledge of the marine world. Here, we use the phylogenetic tree of seagrasses along with their global distributions and a metric of phylogenetic beta diversity to generate a phylo-genetically-based delimitation of marine phytoregions (phyloregions). We then evaluate their evolutionary affinities and explore environmental correlates of phylogenetic turnover between them. We identified 11 phyloregions based on the clustering of phylogenetic beta diversity values. Most phyloregions can be classified as either temperate or tropical, and even geographically disjunct temperate regions can harbor closely related species assemblages. Geographic differences in sea surface temperatures account for more phylogenetic turnover than either water salinity or bathymetry. We also found a strong temperate-tropical gradient in evolutionary dis-tinctiveness, with temperate phyloregions being the most evolutionarily unique. Our results highlight differences between the marine and terrestrial worlds, and suggest that the interplay between long-distance dispersal and phylogenetic niche conservatism played a central role in determining the contemporary distributions of seagrasses worldwide.
Southeast Asia has seen strong climatic oscillations and fluctuations in sea levels during the Quaternary. The impact of past climate changes on the evolution and distribution of local flora in Southeast Asia is still poorly understood. Here we aim to infer how the Quaternary climate change affects the evolutionary process and range shifts in two pine species. We investigated the population genetic structure and diversity using cytoplasmic DNA markers, and performed ecological niche modeling to reconstruct the species past distribution and to project range shift under future climates. We found substantial gene flow across the continuous distribution of the subtropical Pinus yunnanensis. In contrast, the tropical Pinus kesiya showed strong population structure in accordance with its disjunct distribution across montane islands in Indochina and the Philippines. A broad hybrid zone of the two species occurs in southern Yunnan. Asymmetric introgression from the two species was detected in this zone with dominant mitochondrial gene flow from P. yunnanensis and chloroplast gene flow from P. kesiya. The observed population structure suggests a typical post‐glaciation expansion in P. yunnanensis, and a glacial expansion and interglacial contraction in P. kesiya. Ecological niche modeling supports the inferred demographic history and predicts a decrease in range size for P. kesiya under future climates. Our results suggest that tropical pine species in Southeast Asia have undergone evolutionary trajectories different from high latitude species related to their Quaternary climate histories. We also illustrate the need for urgent conservation actions in this fragmented landscape. This article is protected by copyright. All rights reserved.
This datasheet on Alocasia cucullata covers Identity, Overview, Distribution, Dispersal, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Further Information.
Biotectonics is an approach to historical biogeography based on the analysis of independently derived biological and tectonic data, which we demonstrate using the island of Sulawesi as an example. We describe the tectonic development of Sulawesi and discuss the relationship between tectonic models and phylogenetic hypotheses. We outline the problem of interpreting areagrams based on single phylogenies and stress the importance of combining all available data into a general areagram. We analysed the distributions of Sulawesi area of endemism endemics (AEEs) using 30 published phylogenies, which were converted into paralogy-free taxon-area cladograms using the programme LisBeth (Zaragüeta-Bagalis et al. 2012) from which Adam’s consensus trees were constructed using PAUP (Swofford 2002). The results of our analyses show that the relationship between the areas of endemism is congruent with the terrane history of the island. A further 79 phylogenies of Sulawesi species with extralimital distributions were analysed to determine area relationships of Sulawesi within the broader Indo-Pacific region. We demonstrate the utility of data partitioning when dealing with areas that are geologically and biologically composite by showing that analysing Asian and Australasian elements of the Sulawesi biota separately produced general areagrams that avoid artifice and are interpretable in the light of current tectonic models.
Despite discoveries of new species of Metapocyrtus Heller, 1912 (Coleoptera: Curculionidae), in Mindanao Island, Philippines, over the past few years, there are still many unknown species inhabiting unprotected and unexplored forest and mountain ecosystems. A recent survey of Mount Hamiguitan Range Wildlife Sanctuary revealed two new species of the genus. These two species, Metapocyrtus villalobosae, new species, and M. gapudi, new species, from Mount Kabunulan, Hamiguitan Range, Surop, Governor Generoso, Davao Oriental, Philippines, are described. An updated checklist, list of host plants, and brief descriptions of the natural habitat and ecology are also provided.
As an ancient clonal root and leaf crop, taro (Colocasia esculenta, Araceae) is highly polymorphic with uncertain genetic and geographic origins. We explored chloroplast DNA diversity in cultivated and wild taros, and closely related wild taxa, and found cultivated taro to be polyphyletic, with tropical and temperate clades that appear to originate in Southeast Asia sensu lato. A third clade was found exclusively in wild populations from Southeast Asia to Australia and Papua New Guinea. Our findings do not support the hypothesis of taro domestication in Papua New Guinea, despite archaeological evidence for early use or cultivation there, and the presence of appar- ently natural wild populations in the region (Australia and Papua New Guinea). (DOI: 10.1002/ece3.6958) (open access)
As an ancient clonal root and leaf crop, taro (Colocasia esculenta, Araceae) is highly polymorphic with uncertain genetic and geographic origins. We explored chloroplast DNA diversity in cultivated and wild taros, and closely related wild taxa, and found cultivated taro to be polyphyletic, with tropical and temperate clades that appear to originate in Southeast Asia sensu lato. A third clade was found exclusively in wild populations from Southeast Asia to Australia and Papua New Guinea. Our findings do not support the hypothesis of taro domestication in Papua New Guinea, despite archaeological evidence for early use or cultivation there, and the presence of apparently natural wild populations in the region (Australia and Papua New Guinea).
The large, tropical island of Borneo has some of the world’s richest habitats for plant
life, but faces increasing pressures from anthropogenic activities that threaten its biodiversity.
With a good portion of the Bornean flora not critically studied, a comprehensive
documentation of the numerous endemic taxa expected for the island is not yet
complete. It is not known what the relative significance of endemic genera is compared
to Bornean centres of endemism documented or predicted through modelling, and if
they can inform current conservation plans. As a first step, we here present a synopsis
of the endemic genera of Borneo, based on a comprehensive study of literature, herbarium
specimens and distributional data, and an investigation of whether the genera
have been included in molecular phylogenetic studies that confirm their monophyly.
Such a review is timely since many generic delimitations have been shaped by molecular
evidence used to test morphology-based taxonomy, while botanical collection and
revisionary efforts continue. Our findings suggest that 65 vascular plant genera from
25 families may be considered endemic to Borneo. More than two-thirds (48) of these
genera have had at least one species included in molecular phylogenetic studies, but
of these, only 39 have been sufficiently sampled to be considered monophyletic with
high confidence, or they are monotypic. Slightly over half (38) of the endemic genera
are herbaceous. A majority of the genera have fruits or seeds specialised for dispersal by
abiotic vectors, or unspecialised seeds. Almost two-thirds (42) of the endemic genera
are monotypic, and some of these could represent relict lineages. We expect the current
list of endemic genera to be relatively stable and aligned with recent taxonomic concepts,
and that it serves to illuminate an interesting aspect of Borneo’s unique assemblage
of endemic species.
Araceae atau keladi – keladian merupakan tumbuhan yang cukup familiar
bagi masyarakat Bali. Selain sebagai tanaman hias, beberapa jenis juga digunakan
sebagai obat, bahan upacara agama, pangan ataupun makanan ternak. Tujuan
penelitian ini adalah untuk mengetahui keragaman dan potensi Araceae Bali.
Metode penelitian yang digunakan adalah studi pustaka dan observasi. Berdasarkan
data yang diperoleh, Bali diperkirakan memiliki 13 marga yang terdiri dari 21 jenis
Araceae dan dua diantaranya merupakan tanaman introduksi. Sekian jenis Araceae
tersebut memiliki potensi yang beragam bagi masyarakat Bali dan disajikan dalam
bentuk tabel. Potensi tersebut diantaranya sebagai bahan pangan, upacara,
tanaman hias, pakan ternak dan obat. Beberapa negara di luar Indonesia juga telah
banyak menggunakan beberapa jenis Araceae tersebut dan disajikan dalam bentuk
narasi.
The islands of Southeast Asia comprise one of the most geologically and biogeographically complex areas in the world and are a centre of exceptional floristic diversity, harbouring 45,000 species of flowering plants. Cyrtandra, with over 800 species of herbs and shrubs, is the largest genus in the family Gesneriaceae and is one of the most emblematic and species-rich genera of the Malesian rainforest understorey. The high number of species and tendency to narrow endemism make Cyrtandra an ideal genus for examining biogeographic patterns. We sampled 128 Cyrtandra taxa from key localities across Southeast Asia to evaluate the geo-temporal patterns and evolutionary dynamics of this clade. One nuclear and four chloroplast regions were used for phylogenetic reconstruction, molecular dating, and ancestral range estimation. Results from the dating analysis suggest that the great diversity of Cyrtandra seen in the Malesian region results from a recent radiation, with most speciation taking place in the last five million years. Borneo was recovered as the most likely ancestral range of the genus, with the current distribution of species resulting from a west to east migration across Malesia that corresponds with island emergence and mountain building. Lastly, our investigation into the biogeographic history of the genus indicates high levels of floristic exchange between the islands on the Sunda shelf and the important role of the Philippines as a stepping stone to Wallacea and New Guinea. These patterns underlie much of the plant diversity in the region and form an emerging paradigm in Southeast Asian plant biogeography.
New Dacrycarpus megafossils from southern China provide solid evidence for long-distance dispersals from Australia to Asia during the Miocene. This trans-equatorial migration route long post-dates the India-Asia suture and seems to have resulted from the collision of the Australian Plate and Asian Plate after the late Oligocene. Dacrycarpus
is unlikely to have been the only taxon entering Asia via this way, suggesting that this event probably facilitated other biotic exchanges across the equator and contributed significantly to Neogene plant diversity in southern Asia, namely the Dacrycarpus pattern.
Este proyecto se desarrolla para evaluar el efecto de diferentes niveles de inclusión de harina de hoja de bore (A. macrorrhiza) en la dieta de pollos de engorde durante la etapa de finalización y su efecto sobre el desempeño productivo y la sobrevivencia. Se aplica una investigación de tipo experimental con enfoque cuantitativo, para manipular intencionalmente una variable y analizar los resultados. La población corresponde a 200 pollos de engorde de la línea ROSS-308, provenientes de la avícola San Marino Bucaramanga que fueron manejadas en la unidad avícola de la finca San Pablo. Para la muestra se seleccionaron 120 pollos de engorde (60hembras y 60 machos) de la línea ROSS-308 de 30 días de edad. En los resultados se presentan los diferentes niveles de harina de hoja de bore (0, 2, 4, y 8 %) sobre los parámetros productivos de sobrevivencia, consumo de alimento, ganancia de peso, conversión alimenticia, índice de productividad, eficiencia productiva, rendimiento en canal y peso de menudencias, aplicados durante la etapa de finalización. Por último, se determinó la tasa de conversión económica para cada una de las dietas con niveles de inclusión de 0, 2, 4, y 8 % de harina de hoja de bore en la alimentación de estas aves de engorde.
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In this chapter, I present a first consideration of the TNG expansion as an instance of Farming/Language dispersal. In particular, I use historical, ethnobotanical and linguistic data to argue that sugarcane (Saccharum officinarum) and bananas (Musa spp.) are likely to have had a central place in any proto-Trans-New Guinea (PTNG) agricultural package. Sugarcane and banana are well suited to fueling rapid population expansions in that they often have broad altitudinal ranges, don’t require intensive gardening including the irrigation or drainage that taro requires, and can be grown in almost any soil type. The social depth of sugarcane and banana use in New Guinea also attests their historical importance in Melanesian lifestyles. I will consider reconstructions of sugarcane and bananas across the full expanse of the TNG family and show that similar forms are recurrent, particularly at the extremes of the family’s geographical spread. This, I will suggest, indicates that sugarcane and banana must have been part of any agricultural package possessed by early TNG populations.
Taro is an ancient crop native to Asia that is now found in all tropical and warm temperate regions of the world. Its present distribution is the result of a long history of use and of transoceanic translocation. While in the Pacific region much effort has been made to understand the role this plant played in prehistory, in Africa it has not received the same
attention, even though it is a staple crop in some West African countries. Recently, the retrieval of macroremains of desiccated taro at the Islamic port of Quseir al-Qadim in Egypt (Van der Veen & Morales 2011) has revitalised the debate on the history of taro in Africa, and genetic research has been initiated to reconstruct its introduction into the continent.
Fieldwork and a genetic survey of taro in Africa were carried out as part of a project led by Nicole Boivin (University of Oxford) and Robin G. Allaby (University of Warwick). Although analysis of the genetic survey results is ongoing, a geographical and cultural appraisal of taro has now been completed and is presented here.
The nearly cosmopolitan tribe Desmodieae (Fabaceae) includes many important genera for medicine and forage. However, the phylogenetic relationships among the infratribal groups circumscribed using morphological traits are still poorly known. In this study, we used chloroplast (rbcL, psbA-trnH) and nuclear (ITS-1) DNA sequences to investigate the molecular phylogeny and historical biogeography of Desmodieae, and infer ancestral states for several vegetative and reproductive traits. Three groups, corresponding to the Desmodium, Lespedeza, and Phyllodium groups sensu Ohashi were retrieved in the phylogenetic analyses. Conflicts in the topologies inferred from the chloroplast and nuclear datasets were detected. For instance, the Lespedeza clade was sister to the groups Phyllodium+Desmodium based on chloroplast DNA, but nested within the Desmodium group based on ITS-1. Moreover, the New Caledonian endemic genera Arthroclianthus and Nephrodesmus were not monophyletic but together formed a clade, which also included Hanslia and Ohwia based on chloroplast DNA. The hypothetical common ancestor of Desmodieae was dated to the Middle Oligocene (ca. 28.3 Ma) and was likely an Asian shrub or tree producing indehiscent loments. Several colonization events towards Oceania, America, and Africa occurred (all less than ca. 17.5 Ma), most probably through long distance dispersal. The fruits of Desmodieae repeatedly evolved from indehiscence to dehiscence. We also showed that indehiscent loments allow for more variability in the number of seeds per fruit than indehiscent legumes. Modularity seems here to allow variability in the number of ovules produced in a single ovary.
Most population of the Indian Subcontinent is predominantly vegetarian. The local tribes and communities have domesticated a large amount of plant species as vegetables and/or use them as alternative food, involving several genera, such as Cucumis, Coccinia, Luffa, Momordica, Trichosanthes, Solanum, Abelmoschus, Amorphophallus, etc. Additionally, wild species diversity of certain exotic crops has either been extended or introduced to the subcontinent, such as Amaranthus, Dioscorea, etc. Predominant wild species diversity in the Indian Subcontinent occurs for tropical cucurbitaceous, solanaceous, and leguminous vegetable crops and some others, like okra. In addition, wild species diversity is also found in several leafy and rooty, tuberous, and bulbous vegetable crop species, many of whom are directly harvested from the natural habitat by local tribal communities. The complexity of species diversity using different plant parts as vegetables justifies the classification of vegetable crops into three groups, fruity vegetable, leafy vegetable, and root and tuber crops.
A recent exploration for aroids has been conducted in the ever-wet southern part of Mount Lawu, Central Java, Indonesia. Six species belonging to six genera have been recorded. The geographical distribution of Leucocasia gigantea in Central Java is expanded to the southern part. Keys, descriptions and figures are given for all species.
Monocot pollen has traditionally been viewed as monosulcate, dull and boring when compared with pollen of other seed plants. This apparent lack of diversity can at least partially be explained by the fact that monocot pollen does not acetolyse well and has therefore been neglected in studies of comparative pollen morphology, though some notable studies were carried out, for example, Radulescu (1970, 1973), Argue (1974, 1976) and Zavada (1983). However, advances in monocot phylogenetics during the late twentieth and early twenty-first centuries (e.g. Chase et al., 1995, 2000, 2006; Stevenson and Laconte, 1995; Davis et al., 2004) have led to a renaissance in the study of monocot pollen and monocots are now probably the palynologically best-known major angiosperm clade. Detailed studies of exine ontogeny, fossil pollen and the pollen morphology of some large, taxonomically difficult monocot genera have provided useful systematic data (e.g. Le Thomas et al., 2001; Schols et al., 2001, 2003, 2005a, 2005b; Hesse and Zetter, 2007; Smith et al., 2009). Pollen and anther characters including microsporogenesis, pollen apertures and tapetum type have been shown to be of value in monocot systematics, particularly in the lilioid orders Asparagales, Liliales and Dioscoreales, and also in some commelinids such as Arecaceae and Cyperaceae (Rudall et al., 1997, 2000; Caddick et al., 1998; Harley and Baker, 2001; Simpson et al., 2003). Thus it is reasonable to assume that pollen could help to elucidate the problematic systematics of Alismatales. Reciprocally, improved phylogenies of early-divergent monocots (Chen et al., 2004; Chase et al., 2006) could help to shed light on pollen evolution within this group.
What is the link between morphogenesis and phylogeny? This question was addressed by Haeckel, in the nineteenth century, when he formulated his controversial biogenetic law, stating that ontogeny is a short and rapid recapitulation of phylogeny (Haeckel, 1866). Since that time, many zoological and botanical studies discussing the idea of the usefulness of ontogeny in determining phylogeny have been published (e.g. Gould, 1977; Nelson, 1978). Ontogenetic features have been used, for example, to determine the phylogenetic relationships of Saururaceae and Piperaceae (Tucker et al., 1993). On the other hand, Mishler (1986) considered that an independent phylogeny should be established to adequately interpret the evolution of ontogenetic characters. In the present chapter, I will address this general question by using the floral morphogenesis of Araceae as a case study. The Araceae family comprises 117 genera and nearly 3300 species (Haigh et al., 2010). In recent phylogenies, Araceae belong to the Alismatales and are positioned as a sister group of the rest of the order (Stevens, 2001). The family includes eight subfamilies: Gymnostachydoideae, Orontioideae, Lemnoideae, Pothoideae, Monsteroideae, Lasioideae, Zamioculcadoideae and Aroideae, if we accept the recently proposed Zamioculcadoideae (Bogner and Hesse, 2005, Cusimano et al., 2011).
Background and aims:
Anthosachne Steudel is a group of allopolyploid species that was derived from hexaploidization between the Asian StY genome Roegneria entity and the Australasia W genome Australopyrum species. Polyploidization and apomixis contribute to taxonomic complexity in Anthosachne Here, a study is presented on the phylogeny and evolutionary history of Anthosachne australasica The aims are to demonstrate the process of polyploidization events and to explore the differentiation patterns of the St genome following geographic isolation.
Methods:
Chloroplast rbcL and trnH-psbA and nuclear Acc1 gene sequences of 60 Anthosachne taxa and nine Roegneria species were analysed with those of 33 diploid taxa representing 20 basic genomes in Triticeae. The phylogenetic relationships were reconstructed. A time-calibrated phylogeny was generated to estimate the evolutionary history of A. australasica Nucleotide diversity patterns were used to assess the divergence within A. australasica and between Anthosachne and its putative progenitors.
Key results:
Three homoeologous copies of the Acc1 sequences from Anthosachne were grouped with the Acc1 sequences from Roegneria, Pseudoroegneria, Australopyrum, Dasypyrum and Peridictyon The chloroplast sequences of Anthosachne were clustered with those from Roegneria and Pseudoroegneria Divergence time for Anthosachne was dated to 4·66 million years ago (MYA). The level of nucleotide diversity in Australasian Anthosachne was higher than that in continental Roegneria A low level of genetic differentiation within the A. australasica complex was found.
Conclusions:
Anthosachne originated from historical hybridization between Australopyrum species and a Roegneria entity colonized from Asia to Australasia via South-east Asia during the late Miocene. The St lineage served as the maternal donor during the speciation of Anthosachne A contrasting pattern of population genetic structure exists in the A. australasica complex. Greater diversity in island Anthosachne compared with continental Roegneria might be associated with mutation, polyploidization, apomixis and expansion. It is reasonable to consider that A. australasica var. scabra and A. australasica var. plurinervisa should be included in the A. australasica complex.
The genus Alocasia (Schott) G.Don (Araceae) is revised for the Philippines. Fourteen species are recognised, of which four are new to science. A key to the species is provided. All except Alocasia macrorrhizos (L.) G.Don are endemic. Alocasia wenzelii Merr. is placed in the synonymy of A. zebrina Schott ex van Houtte. Alocasia manilensis Engl. and A. warburgii Engl. are synonyms of A. heterophylla (Presl) Merr. Alocasia reversa N.E.Brown is Bornean, not Philippine as originally attributed. The new species (A. boyceana A.Hay, A. clypeolata A.Hay, A. scalprum A.Hay and A. ramosii A.Hay), the frequently misinterpreted Alocasia heterophylla and the very rare A. atropurpurea Engl. are illustrated. Brief notes are made on horticultural value, conservation status, local endemicity and relationships of Philippines Alocasia. Where possible, cultivars recognised by the international horticultural community are ascribed to species.
The excavation of Kilu Cave and the discovery of a Pleistocene prehistory for the Solomon Islands have already been reported in ANTIQUITY by Wickler & Spriggs (62: 703–6). Residue analysis of stone artefacts from the site now provides the earliest direct evidence for the prehistoric use of root vegetables, in the form of starch grains and crystalline raphides identifiable to genus. The direct microscopic identification of starch grains opens new avenues for the study of the plant component of human diets in the distant past.
The flora and fauna of Southeast Asia are exceptionally diverse. The region includes several terrestrial biodiversity hotspots and is the principal global hotspot for marine diversity, but it also faces the most intense challenges of the current global biodiversity crisis. Providing reviews, syntheses and results of the latest research into Southeast Asian earth and organismal history, this book investigates the history, present and future of the fauna and flora of this bio- and geodiverse region. Leading authorities in the field explore key topics including palaeogeography, palaeoclimatology, biogeography, population genetics and conservation biology, illustrating research approaches and themes with spatially, taxonomically and methodologically focused case studies. The volume also presents methodological advances in population genetics and historical biogeography. Exploring the fascinating environmental and biotic histories of Southeast Asia, this is an ideal resource for graduate students and researchers as well as environmental NGOs.
~ Leading researchers provide reviews, syntheses and results of the latest research into Southeast Asian earth and organismal history
~ Covers a wide range of key topics, including palaeogeography, palaeoclimatology, biogeography, population genetics, botany, zoology, conservation biology and evolution
~ Features new methodological developments in population genetics and historical biogeography, offering insight into the latest advances in the field
Geological evidence for plant dispersals in SE Asia is re-viewed by reference to both published, and previously un-published, evidence from the time of first appearance of angiosperms until the Quaternary. It is concluded that angiosperms did not originate in the SE Asian region, but dispersed into the area from West Gondwanaland. Many African plant species dispersed into India as the Indian plate drifted past Madagascar in the Cenomanian/Turonian, and many of their descendants subsequently dispersed into SE Asia following the collision of the Indian plate with Asia in the middle Eocene. Prior to this time, the SE Asian flora appears to have developed in some degree of isolation. There is no palynological evidence for dispersals from the Australian plate in the Cretaceous, and minimal evidence for such dispersals in the Paleocene/Eocene. The Sundanian Eocene flora stretched as far east as the South arm of Sulawesi, and subsequent to the opening of the Makassar Straits in the late Eocene, a part of this flora became stranded to the east of Wallaces Line, and probably formed a major source for other areas to the east of Wallaces Line of taxa of Sundanian and Asiatic affinity, as islands rose above sea level during the Miocene, negating the need for wholesale Miocene dispersal eastward. A small number of plant taxa have dispersed westward across Wallaces Line since the beginning of the Miocene, at 17, 14, 9.5, 3.5 and about 1 Ma. All of the taxa involved were well adapted to dispersal, and emphasise that Wallaces Line has been a substantial barrier to plant dispersal from the Oligocene onward. Since the Eocene, plant dispersals to and from the Sunda region have largely been controlled by climate. The Oligocene and earliest Miocene were moisture deficient over much of the region, with ever-wet rain forest climates first becoming widespread at about 20 Ma in the early Miocene, subsequent to which they have repeatedly ex-panded and contracted. The greatest latitudinal expansion of tropical rain forests occurred at the beginning of the mid-dle Miocene, at which time they extended northward as far as Japan. Fluctuations between wetter and drier climates became more pronounced in the Quaternary, with intergla-cial, high sea level periods coinciding with times of rain forest expansion, and glacial, low sea levels coincided with periods of more strongly seasonal climates, accompanied by the expansion of forests adapted to seasonal climates (such as pine forests) and savannah. A major montane connection existed in South and East Asia through both the Tertiary and late Cretaceous, from the equator to 60 o N, allowing Laurasian mountain plants to dis-perse to and from the equator throughout this period. The survival of representatives of many primitive northern, angiosperm families in lower montane forests within the SE Asian region is thought to be due to the continuous pres-ence of this unbroken mountain belt, rather than an origin in SE Asia. In contrast, the New Guinea mountains were formed only in the middle Miocene, from which time many Gondwanan taxa dispersed into this area from the south. Those well adapted to dispersal, such as Podocarpus imbricatus and Phyllocladus subsequently dispersed widely into SE Asia, whereas those poorly adapted to dispersal, such as Nothofagus, never reached beyond New Guinea.
A review of Alocasia in Thailand is presented. One new species (A. hypoleuca) and three new records (A. acuminata, A. hypnosa & A. perakensis) are reported. A key to Alocasia in Thailand is presented and the new species is illustrated.
Comparative DNA sequencing of matK, a maturase coding gene located within the intron of the chloroplast gene trnK, was evaluated for phylogenetic utility using genera of Saxifragaceae s. str. The entire matK gene was sequenced for two members of the family, Sullivantia sullivantii and Saxifraga integrifolia. Comparison of base substitution rates between these two species indicated that matK evolves approximately three-fold faster than rbcL. Comparative sequencing of 754 base pairs within matK was subsequently conducted using 25 genera in Saxifragaceae s. str. and two outgroup taxa. Summed over the 31 taxa sequenced for this 754 base pair region, 40% of the base positions were variable and 15.6% were potentially informative. Five insertion/deletion events of three or six base pairs were also detected. Skewness and randomization tests both suggest that significant non-random structure is present in the matK data set. Parsimony analyses provided 72 most parsimonious trees of 223 steps (excluding autapomorphies) with a consistency index of 0.565. Several well-supported groups of genera are highly concordant with relationships suggested by two other chloroplast DNA data sets: chloroplast DNA restriction sites and rbcL sequences.
The investigations of thermogenesis of Alocasia macrorrhizos (L.) G. Don inflorescences took place from December 2002 to February 2003, and from February 2004 to March 2004, in one of the wild populations on Espiritu Santo, Vanuatu (South Pacific). Temperatures were measured with six Copper-Constantan (type T) infra-millimetric thermocouples wired to a Campbell Scientific 10X data logger. The thermogenic period lasted 3642 h, and heating was documented on the male part and the sterile appendix. The highest temperatures were recorded on the sterile appendix. They started to rise slightly before midnight and peaked between 0545 and 0600, when the inflorescence odour became the most intense. The average maximum temperature of 59 investigated inflorescences was 43.9 ± 0.6 °C. The absolute maximum was 47.4 °C. The maximum deviation from the ambient air temperature was 25.6 °C. The heating of the male part began 1015 h before the inflorescence odour became the most intense and ended 23 h after the release of pollen. Its temperatures had two peaks: the first one appeared 15 min after the temperature peak of the sterile appendix, whereas the second one appeared at the time of the release of pollen. The dominating visitors of the flowering inflorescences were earwigs (Labidura truncata Kirby, Labiduridae, Dermaptera). Seed set was extremely rare.Key words: giant taro, Alocasia macrorrhizos, thermogenesis, inflorescence development, pollination.
The extraordinary species richness and endemism of the Indo-Australian Archipelago (IAA) exists in one of the most geologically dynamic regions of the planet. The provenance of its biota has been debated, particularly in the area known as Wallacea. Application of molecular genetic approaches and a better understanding of the region's complex geology have stimulated much recent biogeographic work in the IAA. We review molecular phylogenetic and phylogeographic studies in light of current geological evidence. Present distribution patterns of species have been shaped largely by pre-Pleistocene dispersal and vicariance events, whereas more recent changes in the connec-tivity of islands within the Archipelago have influenced the partitioning of intraspecific variation. Many genetic studies have uncovered cryptic species with restricted distributions. We discuss the conservation significance of the region and highlight the need for cross-taxon comparative studies us-ing newly developed analytical approaches well suited to the challenges of historical inference in this region.
Aim To describe current geographical patterns of genetic diversity and infer the his-torical population dynamics of the stone oaks (Lithocarpus) in Southeast Asia. Location We sampled three populations in Indochina: (1) Yunnan province, China; (2) Pyin Oo Lwin area, Myanmar and (3) north-western Vietnam; two in western Borneo: (1) South-western Sarawak and (2) West Kalimantan, Indonesia; two in central Borneo: (1) north coastal Sarawak and (2) north-eastern Sarawak, Malaysia; and two in northern Borneo: (1) Central Sabah and (2) Northern Sabah, Malaysia. Methods A phylogenetic reconstruction of chloroplast DNA sequence variation from numerous individuals of multiple species was used to determine geographical distribu-tion of genetic diversity. A resampling scheme was used to determine the significance of these patterns at different hierarchical levels of the phylogeny. Results were compared with a previously published set of nuclear DNA sequence data.
With the increasing availability of molecular data, maximum likelihood approaches have gained a new central role in phylogenetic reconstructions. Extremely fast tree-search algorithms have been developed to handle data sets of ample size in reasonable time. In the past few years, RAxML has achieved great relevance in this field and obtained wide distribution among evolutionary biologists and taxonomists because of its high computational performance and accuracy. However, there are certain drawbacks with regard to its usability, since the program is exclusively command-line based. To overcome this problem, we developed raxmlGUI, a graphical user interface that makes the use of RAxML easier and highly intuitive, enabling the user to perform phylogenetic analyses of varying complexity. The GUI includes all main options of RAxML, and a number of functions are automated
or simplified. In addition, some features extend the standard use of RAxML, like assembling concatenated alignments with automatic partitioning. RaxmlGUI is an open source Python program, available in a cross-platform package that incorporates RAxML executables for the main operating systems. It can be downloaded from http://sourceforge.net/projects/raxmlgui/.
Keywords: Rapid bootstrap; Graphical user interface; Maximum likelihood; Phylogenetic analyses; Python; RAxML
Consideration of a range of evidence from geomorphology, palynology, biogeography and vegetation/climate modelling suggests that a north-south ‘savanna corridor’ did exist through the continent of Sundaland (modern insular Indonesia and Malaysia) through the Last Glacial Period (LGP) at times of lowered sea-level, as originally proposed by Heaney [1991. Climatic Change 19, 53–61]. A minimal interpretation of the size of this corridor requires a narrow but continuous zone of open ‘savanna’ vegetation 50–150 km wide, running along the sand-covered divide between the modern South China and Java Seas. This area formed a land bridge between the Malaysian Peninsula and the major islands of Sumatra, Java and Borneo. The savanna corridor connected similar open vegetation types north and south of the equator, and served as a barrier to the dispersal of rainforest-dependent species between Sumatra and Borneo. A maximal interpretation of the available evidence is compatible with the existence of a broad savanna corridor, with forest restricted to refugia primarily in Sumatra, Borneo and the continental shelf beneath the modern South China Sea. This savanna corridor may have provided a convenient route for the rapid early dispersal of modern humans through the region and on into Australasia.
Both the fossil record and molecular data support a long evolutionary history for the Araceae. Although the family is diverse in tropical America today, most araceous fossils, however, have been recorded from middle and high latitudes. Here, we report fossil leaves of Araceae from the middle-late Paleocene of northern Colombia, and review fossil araceous pollen grains from the same interval. Two of the fossil leaf species are placed in the new fossil morphogenus Petrocardium Herrera, Jaramillo, Dilcher, Wing et Gomez-N gen. nov.; these fossils are very similar in leaf morphology to extant Anthurium; however, their relationship to the genus is still unresolved. A third fossil leaf type from Cerrejón is recognized as a species of the extant genus Montrichardia, the first fossil record for this genus. These fossils inhabited a coastal rainforest ∼60-58 million years ago with broadly similar habitat preferences to modern Araceae.
The first family-wide molecular phylogeny of the Araceae, a family of about 3800 published species in 120 genera, became available in 1995, followed by a cladistic analysis of morpho-anatomical data in 1997. The most recent and comprehensive family-wide molecular phylogeny was published in 2008 and included species from 102 genera. We reanalyzed the molecular data with a more complete genus sampling and compared the resulting phylogeny with morphological and anatomical data, with a view to contributing to a new formal classification of the Araceae.
We analyzed 113 aroid genera and 4494 aligned nucleotides that resulted from adding 11 genera to the 2008 molecular matrix. We also analyzed 81 morphological characters in the context of the molecular phylogeny, using an extended version of the 1997 morpho-anatomical data set.
The resulting maximum-likelihood phylogeny is well resolved and supported, and most of the 44 larger clades also have morphological or anatomical synapomorphies as well as ecological or geographic cohesion. Of the 44 clades, 16 are here newly circumscribed and informally named. However, some relationships remain poorly supported within the Aroideae subfamily. The most problematic placement is Calla within Aroideae, which conflicts with the distribution of morphological, anatomical, and palynological character states.
The comparison of the molecular analysis with morphological and anatomical data presented here represents an important basis for a new formal classification for the Araceae and for the understanding of the evolution of this ancient family, a monocot group known in the fossil record from the early Cretaceous.
In the second half of the nineteenth century, pioneering discoveries of rich assemblages of fossil plants from the Cretaceous resulted in considerable interest in the first appearance of angiosperms in the geological record. Darwin's famous comment, which labelled the 'rapid development' of angiosperms an 'abominable mystery', dates from this time. Darwin and his contemporaries were puzzled by the relatively late, seemingly sudden and geographically widespread appearance of modern-looking angiosperms in Late Cretaceous floras. Today, the early diversification of angiosperms seems much less 'rapid'. Angiosperms were clearly present in the Early Cretaceous, 20-30 Myr before they attained the level of ecological dominance reflected in some mid-Cretaceous floras, and angiosperm leaves and pollen show a distinct pattern of steadily increasing diversity and complexity through this interval. Early angiosperm fossil flowers show a similar orderly diversification and also provide detailed insights into the changing reproductive biology and phylogenetic diversity of angiosperms from the Early Cretaceous. In addition, newly discovered fossil flowers indicate considerable, previously unrecognized, cryptic diversity among the earliest angiosperms known from the fossil record. Lineages that today have an herbaceous or shrubby habit were well represented. Monocotyledons, which have previously been difficult to recognize among assemblages of early fossil angiosperms, were also diverse and prominent in many Early Cretaceous ecosystems.
Quantification in historical biogeography has usually been based on the search for a single branching relationship among areas
of endemism. Unlike organisms, however, areas rarely have a unique hierarchical history. Dispersal barriers appear and disappear
and may have different effects on different species. As a result, the biota of an area may consist of several components with
separate histories, each of which may be reticulate rather than branching. In an attempt to address these problems, I present
a new biogeographic method, dispersal–vicariance analysis, which reconstructs the ancestral distributions in a given phylogeny
without any prior assumptions about the form of area relationships. A three-dimensional step matrix based on a simple biogeographic
model is used in the reconstruction. Speciation is assumed to subdivide the ranges of widespread species into vicariant components;
the optimal ancestral distributions are those that minimize the number of implied dispersal and extinction events. Exact algorithms
that find the optimal reconstruction(s) are described. In addition to their use in taxon biogeography, the inferred distribution
histories of individual groups serve as a basis for the study of general patterns in historical biogeography, particularly
if the relative age of the nodes in the source cladograms is known.
Subgenus Nothofagus, although geographically restricted at present to temperate areas of South America, has captured much attention in discussions of plant biogeography due to its widespread distribution through Gondwanan continents during the Tertiary. However, phylogenetic relationships within the subgenus Nothofagus have not yet been resolved. We examined geographic patterns of intraspecific and interspecific genetic variation to detect whether incongruences in nuclear or plastid DNA phylogenies occur, in order to better understand the evolutionary history of the subgenus Nothofagus. We conducted spatially-explicit sampling at 10 distinct locations throughout the range of austral South American forests and sampled all present Nothofagus species. We used ITS and chloroplast DNA sequences to estimate phylogenetic relationships. A phylogeny constructed from nuclear genes resolved the subgenus Nothofagus as monophyletic. We found that N. antarctica was a sister to a clade of evergreen species (N. betuloides, N. dombeyi, and N. nitida), while N. pumilio likely diverged earlier. Nine cpDNA haplotypes were distinguished in the subgenus Nothofagus which were associated to geographic locations rather than to taxonomic relationships. This species-independent cpDNA phylogeographic structures within the subgenus Nothofagus may be related to repeated chloroplast capture events over geological time in Patagonia.
Phylogenetic analyses of the Annonaceae consistently identify four clades: a basal clade consisting of Anaxagorea, and a small 'ambavioid' clade that is sister to two main clades, the 'long branch clade' (LBC) and 'short branch clade' (SBC). Divergence times in the family have previously been estimated using non-parametric rate smoothing (NPRS) and penalized likelihood (PL). Here we use an uncorrelated lognormal (UCLD) relaxed molecular clock in BEAST to estimate diversification times of the main clades within the family with a focus on the Asian genus Pseuduvaria within the SBC. Two fossil calibration points are applied, including the first use of the recently discovered Annonaceae fossil Futabanthus. The taxonomy and morphology of Pseuduvaria have been well documented, although no previous dating or biogeographical studies have been undertaken. Ancestral areas at internal nodes within Pseuduvaria are determined using dispersal-vicariance analysis (DIVA) and weighted ancestral area analysis (WAAA).
The divergence times of the main clades within the Annonaceae were found to deviate slightly from previous estimates that used different calibration points and dating methods. In particular, our estimate for the SBC crown (55.2-26.9 Mya) is much younger than previous estimates (62.5-53.1 +/- 3.6 Mya and ca. 58.76 Mya). Early diversification of Pseuduvaria was estimated to have occurred 15-8 Mya, possibly associated with the 'mid-Miocene climatic optimum.' Pseuduvaria is inferred to have originated in Sundaland in the late Miocene, ca. 8 Mya; subsequent migration events were predominantly eastwards towards New Guinea and Australia, although several migratory reversals are also postulated. Speciation of Pseuduvaria within New Guinea may have occurred after ca. 6.5 Mya, possibly coinciding with the formation of the Central Range orogeny from ca. 8 Mya.
Our divergence time estimates within the Annonaceae are likely to be more precise as we used a UCLD clock model and calibrated the phylogeny using new fossil evidence. Pseuduvaria is shown to have dispersed from Sundaland after the late Miocene. The present-day paleotropical distribution of Pseuduvaria may have been achieved by long-distance dispersal, and speciation events might be explained by global climatic oscillations, sea level fluctuations, and tectonic activity.
Understanding the historical dynamics of forest communities is a critical element for accurate prediction of their response to future change. Here, we examine evergreen rainforest distribution in the Sunda Shelf region at the last glacial maximum (LGM), using a spatially explicit model incorporating geographic, paleoclimatic, and geologic evidence. Results indicate that at the LGM, Sundaland rainforests covered a substantially larger area than currently present. Extrapolation of the model over the past million years demonstrates that the current "island archipelago" setting in Sundaland is extremely unusual given the majority of its history and the dramatic biogeographic transitions caused by global deglaciation were rapid and brief. Compared with dominant glacial conditions, lowland forests were probably reduced from approximately 1.3 to 0.8 x 10(6) km(2) while upland forests were probably reduced by half, from approximately 2.0 to 1.0 x 10(5) km(2). Coastal mangrove and swamp forests experienced the most dramatic change during deglaciations, going through a complete and major biogeographic relocation. The Sundaland forest dynamics of fragmentation and contraction and subsequent expansion, driven by glacial cycles, occur in the opposite phase as those in the northern hemisphere and equatorial Africa, indicating that Sundaland evergreen rainforest communities are currently in a refugial stage. Widespread human-mediated reduction and conversion of these forests in their refugial stage, when most species are passing through significant population bottlenecks, strongly emphasizes the urgency of conservation and management efforts. Further research into the natural process of fragmentation and contraction during deglaciation is necessary to understand the long-term effect of human activity on forest species.
Island systems have long been useful models for understanding lineage diversification in a geographic context, especially pertaining to the importance of dispersal in the origin of new clades. Here we use a well-resolved phylogeny of the flowering plant genus Cyrtandra (Gesneriaceae) from the Pacific Islands to compare four methods of inferring ancestral geographic ranges in islands: two developed for character-state reconstruction that allow only single-island ranges and do not explicitly associate speciation with range evolution (Fitch parsimony [FP; parsimony-based] and stochastic mapping [SM; likelihood-based]) and two methods developed specifically for ancestral range reconstruction, in which widespread ranges (spanning islands) are integral to inferences about speciation scenarios (dispersal-vicariance analysis [DIVA; parsimony-based] and dispersal-extinction-cladogenesis [DEC; likelihood-based]). The methods yield conflicting results, which we interpret in light of their respective assumptions. FP exhibits the least power to unequivocally reconstruct ranges, likely due to a combination of having flat (uninformative) transition costs and not using branch length information. SM reconstructions generally agree with a prior hypothesis about dispersal-driven speciation across the Pacific, despite the conceptual mismatch between its character-based model and this mode of range evolution. In contrast with narrow extant ranges for species of Cyrtandra, DIVA reconstructs broad ancestral ranges at many nodes. DIVA results also conflict with geological information on island ages; we attribute these conflicts to the parsimony criterion not considering branch lengths or time, as well as vicariance being the sole means of divergence for widespread ancestors. DEC analyses incorporated geological information on island ages and allowed prior hypotheses about range size and dispersal rates to be evaluated in a likelihood framework and gave more nuanced inferences about range evolution and the geography of speciation than other methods tested. However, ancestral ranges at several nodes could not be conclusively resolved, due possibly to uncertainty in the phylogeny or the relative complexity of the underlying model. Of the methods tested, SM and DEC both converge on plausible hypotheses for area range histories in Cyrtandra, due in part to the consideration of branch lengths and/or timing of events. We suggest that DEC model-based methods for ancestral range inference could be improved by adopting a Bayesian SM approach, in which stochastic sampling of complete geographic histories could be integrated over alternative phylogenetic topologies. Likelihood-based estimates of ancestral ranges for Cyrtandra suggest a major dispersal route into the Pacific through the islands of Fiji and Samoa, motivating future biogeographic investigation of this poorly known region.
Six primers for the amplification of three non-coding regions of chloroplast DNA via the polymerase chain reaction (PCR) have been designed. In order to find out whether these primers were universal, we used them in an attempt to amplify DNA from various plant species. The primers worked for most species tested including algae, bryophytes, pteridophytes, gymnosperms and angiosperms. The fact that they amplify chloroplast DNA non-coding regions over a wide taxonomic range means that these primers may be used to study the population biology (in supplying markers) and evolution (inter- and probably intraspecific phylogenies) of plants.
Pistia stratiotes (water lettuce) and Lemna (duckweeds) are the only free-floating aquatic Araceae. The geographic origin and phylogenetic placement of these unrelated aroids present long-standing problems because of their highly modified reproductive structures and wide geographical distributions. We sampled chloroplast (trnL-trnF and rpl20-rps12 spacers, trnL intron) and mitochondrial sequences (nad1 b/c intron) for all genera implicated as close relatives of Pistia by morphological, restriction site, and sequencing data, and present a hypothesis about its geographic origin based on the consensus of trees obtained from the combined data, using Bayesian, maximum likelihood, parsimony, and distance analyses. Of the 14 genera closest to Pistia, only Alocasia, Arisaema, and Typhonium are species-rich, and the latter two were studied previously, facilitating the choice of representatives that span the roots of these genera. Results indicate that Pistia and the Seychelles endemic Protarum sechellarum are the basalmost branches in a grade comprising the tribes Colocasieae (Ariopsis, Steudnera, Remusatia, Alocasia, Colocasia), Arisaemateae (Arisaema, Pinellia), and Areae (Arum, Biarum, Dracunculus, Eminium, Helicodiceros, Theriophonum, Typhonium). Unexpectedly, all Areae genera are embedded in Typhonium, which throws new light on the geographic history of Areae. A Bayesian analysis of divergence times that explores the effects of multiple fossil and geological calibration points indicates that the Pistia lineage is 90 to 76 million years (my) old. The oldest fossils of the Pistia clade, though not Pistia itself, are 45-my-old leaves from Germany; the closest outgroup, Peltandreae (comprising a few species in Florida, the Mediterranean, and Madagascar), is known from 60-my-old leaves from Europe, Kazakhstan, North Dakota, and Tennessee. Based on the geographic ranges of close relatives, Pistia likely originated in the Tethys region, with Protarum then surviving on the Seychelles, which became isolated from Madagascar and India in the Late Cretaceous (85 my ago). Pistia and Protarum provide striking examples of ancient lineages that appear to have survived in unique or isolated habitats.
We review Phanerozoic sea-level changes [543 million years ago (Ma) to the present] on various time scales and present a new
sea-level record for the past 100 million years (My). Long-term sea level peaked at 100 ± 50 meters during the Cretaceous,
implying that ocean-crust production rates were much lower than previously inferred. Sea level mirrors oxygen isotope variations,
reflecting ice-volume change on the 104- to 106-year scale, but a link between oxygen isotope and sea level on the 107-year scale must be due to temperature changes that we attribute to tectonically controlled carbon dioxide variations. Sea-level
change has influenced phytoplankton evolution, ocean chemistry, and the loci of carbonate, organic carbon, and siliciclastic
sediment burial. Over the past 100 My, sea-level changes reflect global climate evolution from a time of ephemeral Antarctic
ice sheets (100 to 33 Ma), through a time of large ice sheets primarily in Antarctica (33 to 2.5 Ma), to a world with large
Antarctic and large, variable Northern Hemisphere ice sheets (2.5 Ma to the present).
In phylogenetics, the unrooted model of phylogeny and the strict molecular clock model are two extremes of a continuum. Despite their dominance in phylogenetic inference, it is evident that both are biologically unrealistic and that the real evolutionary process lies between these two extremes. Fortunately, intermediate models employing relaxed molecular clocks have been described. These models open the gate to a new field of "relaxed phylogenetics." Here we introduce a new approach to performing relaxed phylogenetic analysis. We describe how it can be used to estimate phylogenies and divergence times in the face of uncertainty in evolutionary rates and calibration times. Our approach also provides a means for measuring the clocklikeness of datasets and comparing this measure between different genes and phylogenies. We find no significant rate autocorrelation among branches in three large datasets, suggesting that autocorrelated models are not necessarily suitable for these data. In addition, we place these datasets on the continuum of clocklikeness between a strict molecular clock and the alternative unrooted extreme. Finally, we present analyses of 102 bacterial, 106 yeast, 61 plant, 99 metazoan, and 500 primate alignments. From these we conclude that our method is phylogenetically more accurate and precise than the traditional unrooted model while adding the ability to infer a timescale to evolution.
Unlabelled:
RAxML-VI-HPC (randomized axelerated maximum likelihood for high performance computing) is a sequential and parallel program for inference of large phylogenies with maximum likelihood (ML). Low-level technical optimizations, a modification of the search algorithm, and the use of the GTR+CAT approximation as replacement for GTR+Gamma yield a program that is between 2.7 and 52 times faster than the previous version of RAxML. A large-scale performance comparison with GARLI, PHYML, IQPNNI and MrBayes on real data containing 1000 up to 6722 taxa shows that RAxML requires at least 5.6 times less main memory and yields better trees in similar times than the best competing program (GARLI) on datasets up to 2500 taxa. On datasets > or =4000 taxa it also runs 2-3 times faster than GARLI. RAxML has been parallelized with MPI to conduct parallel multiple bootstraps and inferences on distinct starting trees. The program has been used to compute ML trees on two of the largest alignments to date containing 25,057 (1463 bp) and 2182 (51,089 bp) taxa, respectively.
Availability:
icwww.epfl.ch/~stamatak
At a time when historical biogeography appears to be again expanding its scope after a period of focusing primarily on discerning area relationships using cladograms, new inference methods are needed to bring more kinds of data to bear on questions about the geographic history of lineages. Here we describe a likelihood framework for inferring the evolution of geographic range on phylogenies that models lineage dispersal and local extinction in a set of discrete areas as stochastic events in continuous time. Unlike existing methods for estimating ancestral areas, such as dispersal-vicariance analysis, this approach incorporates information on the timing of both lineage divergences and the availability of connections between areas (dispersal routes). Monte Carlo methods are used to estimate branch-specific transition probabilities for geographic ranges, enabling the likelihood of the data (observed species distributions) to be evaluated for a given phylogeny and parameterized paleogeographic model. We demonstrate how the method can be used to address two biogeographic questions: What were the ancestral geographic ranges on a phylogenetic tree? How were those ancestral ranges affected by speciation and inherited by the daughter lineages at cladogenesis events? For illustration we use hypothetical examples and an analysis of a Northern Hemisphere plant clade (Cercis), comparing and contrasting inferences to those obtained from dispersal-vicariance analysis. Although the particular model we implement is somewhat simplistic, the framework itself is flexible and could readily be modified to incorporate additional sources of information and also be extended to address other aspects of historical biogeography.
Alocasia hypnosa J.T. Yin, Y.H. Wang & Z.F. Xu is described and illustrated as a new species of Araceae from southern Yunnan, China. It occurs also in Thailand. The morphological characters of A. hypnosa and the related species A. odora are compared. Alocasia hypnosa differs from A. odora in its purple spathe lamina, tubercle-bearing stolons and seasonally dormant habit. An identification key to the Chinese species of Alocasia is provided.
