Oceanic islands have isolated biota, which typically include many endemic species. However, island endemics are vulnerable due to small population sizes, and they are often threatened by habitat destruction or by introduced pests and predators. Adequate conservation planning requires good information on genetic variability and population structure, also when seemingly viable species are considered. Here, I analysed the genetic structure in the terrestrial orchid Dactylorhiza foliosa, which is endemic to Madeira. This species is a characteristic component of evergreen laurel forests occupying the northern slopes of the island. Levels of diversity in both the plastid genome and in the nuclear genome were comparable to levels of diversity found in congeners growing in continental regions. Within populations, plants separated by distances up to 256 m shared plastid haplotypes significantly more often than plants at random, but when nuclear markers were considered, only plants growing closer than eight metres were significantly more closely related. Analysis of plastid marker variation revealed that gene dispersal by seeds is not sufficiently large to counterbalance the accumulation of mutations that build up divergence between the most distant populations. However, differentiation in the nuclear genome was considerably smaller, suggesting that gene dispersal by pollen is much more efficient than gene dispersal by seeds in D. foliosa. The overall pollen to seed dispersal ratio, mp/ms, was 7.30. Considering genetic parameters, conditions for long-term persistence of D. foliosa on Madeira seem to be good.
The genus Anthemis has a circum-Mediterranean distribution and comprises c. 175 annual, biennial, and perennial species with polyploid species and species complexes found in its section A. sect. Hiorthia. In Sicily, the genus is represented by 13 species, one of these being the tetraploid A. cupaniana, which is endemic to the island and is distributed throughout the limestone mountains at elevations between 500 and 1800 m a.s.l. Discordant positions in phylogenetic trees based on two plastid regions (psbA-trnH and trnC-petN) and on one nuclear marker (nrDNA ITS1 + 5.8S + ITS2) reveal that the species is of allopolyploid origin, with the maternal parent from the species group around A. cretica and the paternal one from a monophyletic group comprising mostly N African representatives around A. pedunculata. Owing to the fact that the latter group also comprises the Sicilian perennial and diploid A. ismelia and that A. cretica has been found with diploid populations in the C Sicilian Madonie Mts, these two species are considered being the most probable parental diploids of A. cupaniana. The close relationship of A. ismelia with the N African A. pedunculata group supports the biogeographical interpretation of A. cupaniana being the result of a ‘collision’ between diploids from the southern (African) and northern (Eurasian) platforms after dispersal along a Pleistocene corridor in the Sicilian channel.
Geranium erianthum is an alpine plant growing in dry habitats, which is distributed from East Asia to northern coastal regions of the northern Pacific. The ice-free area around the current Bering Strait (i.e., Beringia) had played an important role in range expansion into neighboring regions such as East Asia and North America for some alpine plants. However, recent studies suggest that some alpine plants in snowbed environment spread from East Asia to northern coastal regions of the northern Pacific. In this study, we investigated phylogenetic relationships and genetic differentiations among populations of G. erianthum and the related species using the chloroplast genome and single-nucleotide polymorphisms, to evaluate the alternative biogeographic hypotheses in which region of Beringia, British Columbia or East Asia is probable for its distributional origin. Range reconstruction based on phylogenetic tree of chloroplast genome indicated G. erianthum and related species originated in East Asia, from where G. erianthum migrated eastward into Beringia and British Columbia. In addition, nuclear genome-wide SNPs indicated that no significant genetic differentiation was detected between Japanese and Beringian populations. The lack of genetic differentiation suggests that the current range of G. erianthum resulted from rapid range expansion during the latter period of the last glacial era. Overall, the East Asian refugium hypothesis was applicable to the alpine plant G. erianthum in dry habitat, indicating that range expansion pattern from East Asia into the northern Pacific may be more common rather than limited for snowbed species.
The shrub Trixis praestans (Asteraceae) is widely distributed in Argentina, Brazil, Uruguay and Paraguay. It has great potential as a melliferous resource, since its abundant flowering occurs in winter (when flower offer is scarce) and spring, and it is intensely visited by honey bees. This study provides information on some aspects of the reproductive biology, which are essential for the species cultivation, conservation and breeding. Flowering phenology, floral biology and floral visitors were observed. The mechanism of fruit set was evaluated through manipulative experiments, embryological analyses and genotypic characterization of offspring using molecular DNA markers. Flower longevity was 3.5 ± 1 days and duration of the capitulum in floral state was 15 ± 6 days; peak flowering occurred in mid-August. Floral visitors belonged to nine species of the orders Hymenoptera, Diptera and Lepidoptera. Apis mellifera was the most abundant species and showed foraging behavior on pollen and nectar. Fruit set was 70% higher in open-pollination and hand cross-pollination (xenogamy) treatments than in hand self-pollination and autonomous self-pollination treatments. The embryological analysis indicated a path of sexual development which originated a reduced embryo sac (female gametophyte). Molecular analysis showed a prevalence of cross-fertilization in fruits derived from open-pollination. Based on the results, we conclude that T. praestans is a sexual species in which xenogamy predominates and that pollinators are necessary for fruit set.
Gleichenia (Gleicheniaceae) is a genus of distinctive branching ferns well represented in Australasia (Australia, New Caledonia, and New Zealand) where seven of the total eleven species occur. Published chloroplast phylogenies have shown that G. dicarpa is polyphyletic in New Zealand, and that one species from Madagascar and Réunion previously included in Gleichenia represented a separate newly-recognised genus, Rouxopteris. Here, chloroplast rbcL, trnL-trnF and combined trnL-trnF and rps4-trnS phylogenies are produced for all Australasian species. Australasian species formed a clade sister to the type of Gleichenia, G. polypodioides, confirming their placement in Gleichenia. Gleichenia dicarpa occurred in three major clades, which also contained other species or undescribed forms. The three separate lineages of G. dicarpa were morphologically distinct from these other species or forms; however, the three separate chloroplast lineages of G. dicarpa are difficult to morphologically distinguish from each other. Further study is required to elucidate whether the polyphyly of G. dicarpa could be due to unrecognised cryptic species, hybridisation, or incomplete lineage sorting. Low rbcL variation between all Australasian species suggests a radiation in the last five million years and at least six long-distance dispersal events in Australasia are inferred, comprising five between Australia and New Zealand, and one between Australia and New Caledonia.
A critical taxonomic and nomenclatural review of the Brazilian species of Acalypha (Euphorbiaceae, Acalyphoideae) is presented. As a result, 40 species (44 taxa including six subspecies) are accepted, 37 of them native (17 endemic) and three introduced; also, 132 names are considered synonyms, 28 of them for the first time. Two new combinations are proposed: Acalypha brasiliensis subsp . asterotricha and A. brasiliensis subsp . psilophylla , previously considered varieties of A. brasiliensis. Information about types is provided for all the valid names, and 54 lectotypes and one neotype are designated. Identification keys and detailed distribution maps of all the native taxa are also provided.
Geastrum is a genus with worldwide distribution and the most species-diverse in the family Geastraceae and is easily recognized by the star-like basidioma in the majority of species. The most recent and accepted classification based on phy-logenetic, morphological and chemical data, subdivided the genus into 14 sections. The section Exareolata is formed by eleven species from which only G. echinulatum and G. verrucoramulosum are truly stipitate. During field trips in Brazilian Amazonia, we found a stipitate species of Geastrum. Based on morphological and phylogenetic data, we propose it as a new species for the genus, which forms a sister group of G. verrucoramulosum and is allocated in sect. Exareolata. Geastrum squameoramulosum sp. nov. is characterized by a prominent and well-developed ramified stipe and the presence of scales on the outer surface of the exoperidium. It is known so far only from the Amazon rainforest. We also provide an updated key to the species in this section.
Historically, and even today, discovery of new species has remained one of the primary research activities driving the discipline of taxonomy. Discovering scientifically still unknown biodiversity is critical in addressing the taxonomic impediment which is hampering our progrees to meet the challenges of global biodiversity crisis. However, in the rush to accelerate the rate of new species’ discoveries, it is crucial to follow objective, stable and reproducible taxonomic criteria. Otherwise, new species’ discoveries based solely on subjective, unstable and non-reproducible characters can be cause of artificial taxonomic inflation in biodiversity data with wider implications on conservation policy and practice. In this study, by integrating empirical evidences from multiple sources, we critically evaluate the validity of two recently described new species of Ephedra in India (E. sumlingensis and E. khurikensis) to underscore that all ‘new’ species are not always new. Use of morphologically plastic characters in diagnosis, descrepancies in the protologues and inconsistencies with the freshly collected live specimens from the type localities clearly revealed that both these species unambiguosly fall within the circumscription of already known E. intermedia. With further support from robust analyses of morphometric amd molecular data, we recognise both the species as new synonyms of E. intermedia. Based on the lessons learnt from this study, we provide suggestions to be practised by the taxonomists to avoid such pitfalls in biodiversity data due to arbitrary new species’ discoveries.
In 2015, Brazil faced the worst environmental disaster in its history, when the collapse of an iron ore dam dumped millions of tons of tailings into the Doce River. In this paper, we describe two Hippeastrum species native to localities directly involved in the tragedy. The dam was located in the foothills of Serra do Caraça, a mountain range in the state of Minas Gerais, from where we describe the endemic H.carassense; H.velloziflorum was first found on an inselberg located on the banks of the Doce River, in the neighboring state of Espírito Santo. Comments on their distribution, ecology, and phenology are provided, as well as comparisons with the most similar taxa. The conservation status of the two new species is preliminarily assessed, and both are considered threatened with extinction. We also compared their leaf anatomy and micromorphology with related species of Amaryllidaceae. Based on nrDNA ITS, we infer the phylogenetic position of H.velloziflorum, a taxon with several unique morphological characters for Hippeastrum, as the first branch in subgenus Hippeastrum. The placement of H.velloziflorum in Hippeastrum is also supported by anatomical and cytological data. The somatic chromosome number was 2n = 22, and the karyotype formula was 2n = 8m + 12sm + 2st chromosome pairs. An identification key to the species of Hippeastrum occurring in the Doce and Jequitinhonha River basins is presented.
Based on molecular and morphological evidence, two species of Seseli sect. Eriocycla subsect. Cordata are described as a new genus, Shomalia. The new genus is related to the Iranian endemic genus Azilia; the taxa have the following common diagnostic features: similar plant architecture, imparipinnate leaves, leaf segments ovate or orbiculate, with obtuse or cuneate basis and dentate or dissected margin coming down over abaxial surface, up to five linear bracts present, and late blooming and fruiting. At the same time, Shomalia, gen. nov. differs from Azilia in carpological features: it has elongated or lanceo-late mericarps, terete in cross-section, covered with non-branching simple hairs or glabrous (vs. elliptic glabrous mericarps strongly compressed from the dorsal side in Azilia), morphology of the underground part (multi-branched woody rootstock vs. thickened and non-branching rootstock), and number of stems (numerous vs. solitary).
This study aimed to reveal the evolutionary timescale and processes underlying the diversity of Rubus in the Japanese Archipelago. We conducted molecular phylogenetic analyses of most native species (35 species), along with previously published data from 116 foreign species, based on nuclear ribosomal internal transcribed spacer (ITS) and chloroplast DNA sequences. Most of the northern species of Japan, that is, Rubus chamaemorus, R. pedatus, R. vernus, R. pseudojaponicus, and R. ikenoensis, were found to belong to anciently diverged lineages; in particular, R. ikenoensis formed a unique lineage distinct from other species. The other species diverged into two evolutionary groups. One included subg. Malachobatus, Chamaebatus, and sects. Pungentes, Idaeanthi, and Parvifolii (subg. Idaeobatus), which was further divided into two clades in the chloroplast phylogenies. Although the phylogenetic structures within this group were unresolved, R. sieboldii has been proven to be recently derived. The second group represented a well-supported clade, comprising sects. Microphylli, Corchorifolii, Peltati, and Rosifolii (subg. Idaeobatus) and suggested early Miocene diversification of this Asian lineage associated with character specialization in vegetative reproduction and leaf shape. This clade was further resolved into lower clades primarily representing the sectional classifications, although the placement of the earliest diverged species, R. sumatranus, R. peltatus, R. corchorifolius, and R. chingii, was incongruent among gene trees. At the lower taxonomic levels, R. illecebrosus, R. grayanus, and the thornless species of sect. Microphylli showed earlier divergence.
Orchidaceae is among the largest plant families in the world; that is why it is notoriously difficult to identify species using traditional taxonomic methods. This problem is especially apparent in the Andean region of South America, a global hot-spot for orchid diversity. Plant DNA barcoding has been proposed to help with orchid species discrimination. However, the utility of the rbcL and matK DNA barcode markers to discriminate between orchid species still needs investigating. The goal of this study is to determine the utility of the rbcL and matK DNA barcode markers to discriminate orchid species from a localized Andean montane forest in Ecuador. A total of 174 samples from the Siempre Verde Preserve, Ecuador, were sequenced, returning 51 unique rbcL and 81 unique matK barcode gene region sequences. Similar rates of sequencing success, rbcL (76%) and matK (75%), were found for both gene regions. Sequences were then queried to GenBank, where top matches were compared to the taxonomic identification of samples. Analysis of 132 unique orchid sequences indicated that, overall, the matK gene region was more robust for species (63%) and genus level (78%) discrimination compared to the rbcL gene region (species: 29%; genus: 36%). However, for 11 of 29 genera, rbcL and matK had similar success at genus level discrimination. Collectively, results emphasize the utility of the matK DNA barcode for the discrimination of orchid taxa and the importance of incorporating taxonomic and genetic methods when investigating the identity of plant species from complex groups.
The genus Cyrtomium is one of the most taxonomically challenging groups, which comprises about 40 taxa globally. Cyrtomium yamamotoi is a great example showing the taxonomic difficulties in the genus. The plant was first described as a variety (C. fortunei var. intermedium), thereafter the rank was moved to a species by Tagawa in 1938. Cyrtomium yamamotoi and its related taxa including five varieties of C. fortunei are triploid apogamous taxa with high morphological variabilities. The substantial morphological variations likely resulted from hybrid origins leading to various taxonomic complications. To determine the species boundary between C. yamamotoi and the C. fortunei complex, we inferred the phylogenetic relationships among the complex and the five related taxa including C. falcatum using the two widely used cpDNA regions, rbcL and psbA-trnH IGS. We also carefully examined the nomenclatural histories of eleven Cyrtomium taxa (five taxa of C. fortunei complex and six related taxa) and the key morphological characters. According to our analysis, Cyrtomium yamamotoi is likely an independent species as the phylogenetic results revealed that C. yamamotoi was separated from the C. fortunei complex while all members of C. fortunei complex formed a monophyletic clade.
Withania somnifera (L.) Dunal is a promising herb with many pharmaceutical and therapeutic uses ranging from immunomodulation to anticarcinogenicity. It is commonly known as Indian ginseng, as it is comparable to Panax ginseng, which is a widely studied and utilized herb. There are limited studies on the genetic diversity of W. somnifera from the northeastern region of the Indian Subcontinent. This paper describes the characterization of wild accessions collected from Tamil Nadu State. A total of 15 accessions collected from wild populations were studied for their physical leaf traits such as leaf fresh weight (g), dry weight (mg), leaf dry matter content (mg g-1), specific leaf area (mm 2 mg-1), leaf size (mm 2), total carbon and nitrogen , and total withaferin-A content in leaves. An attempt was made to correlate physical leaf traits with withaferin-A content. The molecular traits, which were treated in a presence-absence matrix, failed to group the hyper-witha-ferin-A accessions. The quantified physical leaf traits were converted into a presence-absence matrix using a novel method of class-based stratification. The phenetic relations inferred from the Fitch-Margoliash algorithm applied to physical leaf trait data resulted in grouping of accessions with high withaferin-A content. These traits were used in the selection of promising accessions which can be further used for breeding programmes.
Historically, and even today, discovery of new species has remained one of the primary research activities driving the discipline of taxonomy. Discovering scientifically still unknown biodiversity is critical in addressing the taxonomic impediment which is hampering our progrees to meet the challenges of global biodiversity crisis. However, in the rush to accelerate the rate of new species’ discoveries, it is crucial to follow objective, stable and reproducible taxonomic criteria. Otherwise, new species’ discoveries based solely on subjective, unstable and non-reproducible characters can be cause of artificial taxonomic inflation in biodiversity data with wider implications on conservation policy and practice. In this study, by integrating empirical evidences from multiple sources, we critically evaluate the validity of two recently described new species of Ephedra in India (E. sumlingensis and E. khurikensis) to underscore that all ‘new’ species are not always new. Use of morphologically plastic characters in diagnosis, descrepancies in the protologues and inconsistencies with the freshly collected live specimens from the type localities clearly revealed that both these species unambiguosly fall within the circumscription of already known E. intermedia. With further support from robust analyses of morphometric amd molecular data, we recognise both the species as new synonyms of E. intermedia. Based on the lessons learnt from this study, we provide suggestions to be practised by the taxonomists to avoid such pitfalls in biodiversity data due to arbitrary new species’ discoveries.
The goal of this study was to assess breeding systems, and inbreeding and outbreeding depression in four vegetation types in the Venezuelan central plains: forest, ecotone, savanna and disturbed areas. Such analysis allowed inferring how reproductive systems are influenced by the structure and complexity of the vegetation. This analysis was conducted considering the life form, successional stage, dispersal syndrome, pollination system specificity, and flowering time. Information on sexual systems, dichogamy and herkogamy, was also included. Experimental pollination tests were carried out on 115 plant species belonging to 41 plant families. Most species were non-agamospermous, and tended to have a mixed breeding system: partially spontaneous self-pollinated, and partially xenogamous. Xenogamous and non-spontaneous self-pollinated species were the second most frequent categories, which are represented by woody species, dispersed by frugivores or abiotically, with polyphilous and monophilous pollination systems, that flower during dry periods in the forest and forest-savanna transition. The high incidence of partial self-incompatibility was associated with herbaceous species, seed dispersal by granivores and epizoochory, and flowering throughout the rainy period in the herbaceous communities. Self-incompatibility was mainly associated with the woody condition and flower production during the dry period in forest communities. The proportion of species with inbreeding depression increased from forest to disturbed areas, and was frequently related with herbs, seed dispersal by granivores and epizoochory, and flowering during the rainy period. Outbreeding strategies and inbreeding depression increased from disturbed areas to forest along with the increase in woody life forms, frugivory and wind dispersal, and flowering during drought period.
Morphoanatomical features can provide useful information for plant taxonomy. In Oxalis sect. Polymorphae (Oxalidaceae) there are currently 12 accepted species, mostly from the Brazilian Atlantic Forest, but the historical recognition of some infraspecific taxa may have resulted in underscored species richness. Integrated analyses of additional types of data are critical to evaluate if some taxa would be better recognized at species level. To evaluate this, we carried out leaf morphoanatomical analysis of O. neuwiedii subsp. neuwiedii and O. neuwiedii subsp. pardoensis and a phylogenetic analysis of nrITS sequences. Both leaf morphoanatomy and phylogenetics lend support to recognize O. neuwiedii subsp. pardoensis at species level. Leaflet venation pattern, epidermal cell outline, hair-covering, vascular conformation of the pulvina, and tissue organization in the midvein were the main morphoanatomical diagnostic features for the recognition of two species instead of a single one. A new rank and the second-step lectotypification are proposed for this taxon, raising to 13 accepted species in O. sect. Polymorphae.
Variations among stamens and styles are widespread in angiosperms. In both heteranthery and heterostyly, variation in styles and stamens is considered an outcome of selective forces driven mainly by pollinators. Macairea radula (Melastomataceae) has two stamen sets, poricidal anthers, pollen as the main floral resource and flowers visited by vibrating bees, a set of traits related to heteranthery. However, tristyly, which also predicts stamens differences within the same flower, has been proposed as a possible floral system for this species. We describe the variation in length of stamens and styles in two populations of this species considering the interaction with their pollinators. Both populations showed high variation in stamen and style lengths with length overlap between floral types. These populations also showed low reciprocity between stamens and styles. In one chosen population, where we evaluated fruit formation after controlled pollination and checked the individual floral types, plants were partially self-incompatible and there was no proportional representation of floral types (anisoplethy). These results suggest that M. radula does not follow the theoretically expected patterns of the tristylous systems, because there is a flexibility in all heterostylous traits analyzed within populations. Considering the length of bee bodies as well as their behavior, stamens and styles could be associated with bee feeding or plant reproduction, as occurs in heteranthery. Our study points out that the evaluation of floral systems only based in floral morphological traits without considering the morphology and behavior of pollinators may be misleading in some cases.
Croton guaritensis, sp. nov. is here described, illustrated, and classified based on morphological and molecular data. The new species is restricted to the Pampa biome where it grows around rocky outcrops. Examination of the morphology from herbarium collections and field observations, as well as evidence from molecular analysis, indicate that Croton guaritensis belongs to Croton section Barhamia subsection Medea. Croton subsection Medea is represented by several rare and endemic species and stands out by its glandular structures in stipules, bracts, and sepals. The new species differs from other species of this subsection in the indumentum on branches and leaves, which consists of subentire lepidote trichomes, and in the sepals of staminate and pistillate flowers that have stipitate glands. An identification key to the new species and closely related taxa in southern Brazil is provided, as well as a preliminary conservation status.
Trillium apetalon (4×) and T. tschonoskii (4×) hybridize commonly where both species grow sympatrically, leading to the formation of tetraploid T. miyabeanum in Hokkaido, Japan. The present study aimed to determine which isolation factor is responsible for the frequency and asymmetry of hybrid T. miyabeanum formation in a sympatric population of T. apetalon and T. tschonoskii. We examined the contributions and strengths of four reproductive isolation barriers of T. miyabeanum formation: flowering phenology, breeding system, genetic isolation, and hybrid inviability. In addition, we also investigated the effect of flowering phenology on reproductive success (i.e., seed production and outcrossing rates) and outputs (i.e., ovule production) for T. apetalon and T. tschonoskii. We calculated the absolute contribution of each isolation barrier to the total reproductive isolation and found that flowering phenology and differences in breeding systems between the two parental species were more effective when T. apetalon was the maternal parent. Furthermore, hybrids with T. apetalon as the maternal parent had lower viability than those of the reciprocal cross and did not reach the flowering stage. Particularly, absolute contribution of premating isolation, especially by flowering phenology and breeding system, was higher than that of other isolation factors for both crossing directions. For the formation of T. miyabeanum, we concluded that asymmetry of hybridization between T. apetalon and T. tschonoskii would be caused by strong premating isolations. The asymmetry of the isolating barriers may promote T. tschonoskii as the maternal parent of T. miyabeanum.
The population genetic structure was proved to be influenced by both historical events and gene flow, which can be examined by analyzing intraspecific differentiation and spatiotemporal population dynamics of a species at large spatial scale. In this study, we surveyed the population structure and evolutionary dynamics of 38 natural populations of a desert plant, Allium mongolicum Regel (Liliaceae), in northwestern China, using nine microsatellite loci. High genetic diversity was observed within populations, with mean allele diversity and the expected heterozygosity values of 0.689 and 0.655, respectively. The value of expected heterozygosity (He = 0.655) was higher than that of observed heterozygosity (Ho = 0.317), which indicated an excess of homozygosity within populations, which could be due to inbreeding. The gene flow among populations was high (Nm = 1.245) while the genetic differentiation among populations was low (Fst = 0.169). However, a distinct regional-scale differentiation was discerned among three geographical regions. Our results further detected considerably restricted but asymmetric gene flow among the three regions. The demographic dynamic analysis also detected an ancient population contraction and subsequent expansion during 0.11–0.33 Ma. These results suggested that both gene flow and population contraction/expansion caused by climate oscillations in ancient time played an important role in forming the population structure and accelerating the regional-scale differentiation of the desert plant. Our results further enforce the idea that the aridification and subsequent desert expansion/contraction since Pleistocene have greatly promoted the habitat fragmentation, and subsequent plant differentiation in northwestern China.
Saccharum s.l. comprises 35–40 species, including sugarcane (S. officinarum), and is distributed in the tropics and subtropics. The term “Saccharum complex” refers to four related genera: Saccharum, Erianthus s.l. (including E. sect. Ripidium, or Tripidium), Narenga, and Sclerostachya. Miscanthus and Miscanthidium are also closely related to this group. The delimitation of these genera is contentious and largely unresolved, with most species recognized under Saccharum. This study aimed to assess the morphological variation of the Saccharum complex, especially Saccharum s.s. and Erianthus s.l., and contribute to clarifying their generic circumscriptions. To accomplish this purpose, 31 exomorphological characters (17 qualitative and 14 quantitative) were analyzed using cluster (UPGMA) and discriminant analyses. The existence of significant differences among groups was analyzed by a one-way MANOVA. The morphological evidence clearly indicated three groups: (1) Saccharum s.s. from the Old World, (2) Tripidium + some species of Saccharum s.l. sometimes recognized as Narenga, Miscanthus, or Miscanthidium (all taxa from the Old World), and (3) Erianthus s.s. from the New World. The results support that the native species from the New World (Erianthus s.s.) are morphologically different from the species of Saccharum s.s. often cultivated, suggesting that Erianthus should be accepted as a genus distinct from Saccharum. For the species of Tripidium, we provide the morphological traits that distinguish them from Saccharum s.s. and Erianthus s.s. and revalidate the recent differential recognition postulated by molecular works.
The grass Deschampsia cespitosa is a variable taxon out of which many varieties, subspecies and endemic species have been separated. In this paper, the variation in genome size (GS) and ploidy of this grass including several of its subspecies and two related species in Eurasia was investigated by flow cytometric (FCM) measurements. GS and ploidy data were also related to specific environments and reproduction mode. Ploidy levels found by FCM were confirmed by chromosome counts of diploid (2n = 28) and tetraploid (2n = 52) samples. Seminiferous (seed bearing) D. cespitosa was mainly diploid (GS between 3.754 and 5.438 pg/1C). GS variation in diploids showed a geographic pattern with a significant difference (H = 41,441, P < 0.001) between European (median = 4.377 pg) and Asian (median = 4.881 pg) accessions. Genome size (1C) in tetraploids ranged from 7.9426 to 9.0399 pg. Tetraploid seminiferous D. cespitosa was found mostly in disturbed habitats in western and southern Europe, while tetraploids in Asia were registered in wet Arctic habitats. Genome size (1C between 8.3278 and 8.8603 pg) of the pseudoviviparous plants (spikelets produce plantlets asexually) of wet habitats in central and northern Europe indicated tetraploidy. A putative triploid (GS 6.6817 pg) was detected in Iceland. Summing up, we found a high variation in GS on the geographic scale with significant regional differences in diploid D. cespitosa. Among the tetraploids, the asexually reproducing plants were bound to specific habitats, while the seminiferous plants showed a habitat preference similar to the diploids.
In the hyperarid Atacama Desert, water availability plays a crucial role in allowing plant survival. Along with scant rainfall, marine advective fog frequently occurs along the coastal escarpment fueling isolated mono-specific patches of Tillandsia vegetation. In this study, we investigate the lipid biomarker composition of the bromeliad Tillandsia landbeckii (CAM plant) to assess structural adaptations at the molecular level as a response to extremely arid conditions. We analyzed long-chain n -alkanes and fatty acids in living specimens ( n = 59) collected from the main Tillandsia dune ecosystems across a 350 km coastal transect. We found that the leaf wax composition was dominated by n -alkanes with concentrations (total average 160.8 ± 91.4 µg/g) up to three times higher than fatty acids (66.7 ± 40.7 µg/g), likely as an adaptation to the hyperarid environment. Significant differences were found in leaf wax distribution (Average Chain Length [ACL] and Carbon Preference Index [CPI]) in the northern zone relative to the central and southern zones. We found strong negative correlations between fatty acid CPI and n -alkane ACL with precipitation and surface evaporation pointing at fine-scale adaptations to low moisture availability along the coastal transect. Moreover, our data indicate that the predominance of n -alkanes is reflecting the function of the wax in preventing water loss from the leaves. The hyperarid conditions and good preservation potential of both n -alkanes and fatty acids make them ideal tracers to study late Holocene climate change in the Atacama Desert.
The monospecific genus Aitchisonia (Rubiaceae), a suffrutescent plant endemic to Afghanistan, Iran, and Pakistan, was merged in the genus Plocama of the monogeneric tribe Putorieae sensu Backlund et al. (Spermacoceae alliance, subfamily Rubioideae). This decision was based on the phylogenetic placement of the specimen Rafei and Zangooei 25651 (FUMH) erroneously identified as Aitchisonia rosea in Plocama. This specimen was later correctly re-identified as Plocama dubia, rending the position of Plocama rosea (= Aitchisonia rosea) in Plocama (thus Putorieae) doubtful. We reconstructed a new phylogeny of Spermacoceae alliance based on trnL-F and nrITS sequence data and using the Bayesian method to: 1) assess the phylogenetic placement of P. rosea within Rubioideae, using new material from Iran; 2) pinpoint the phylogenetic positions of Plocama asperuliformis, P. crucianelloides, P. dezfulensis, P. ehrendorferi, P. kandaharensis, P. szowitsii, and P. vassilczenkoi; and 3) reassess the monophyly of Plocama bruguieri and P. eriantha. The trnL-F and nrITS trees further support the monophyly of the Rubieae complex, but were not fully congruent. The trnL-F tree resolved Plocama rosea as sister to tribe Rubieae (including Kelloggia), while the nrITS tree was inconclusive. We described a new monogeneric tribe Aitchisonieae to accommodate P. rosea. Our nrITS analysis resolved Plocama crucianelloides in the Plocama Middle-Eastern clade and P. asperuliformis, P. dezfulensis, P. ehrendorferi, P. kandaharensis, P. szowitsii, and P. vassilczenkoi in the Plocama Central-Asian clade, both sensu Rincón-Barrado et al. The non-monophyly of P. bruguieri and P. eriantha is confirmed.
Adaptation to pollinators can include the spatial arrangement of flowers on inflorescences. A brush-like arrangement of flowers has evolved in multiple plant families. The accessible rewards in these “brush flowers” are often utilized by both birds and insects, making it challenging to assess which are the main contributors to pollination. We investigated two such species, Scadoxus puniceus and S. membranaceus, by means of camera trapping, direct observations, and selective exclusion and controlled pollination experiments in order to determine the extent to which sunbirds contribute to their pollination. We found that flowers of S. puniceus are frequently visited by sunbirds, butterflies and honeybees, whereas those of S. membranaceus are rarely visited. Birds typically perch directly on the densely packed flowers of S. puniceus and pick up large, visible pollen loads on their beaks, heads and feet as they feed on nectar. The flowers of this species match the bills of the sunbirds in length, and the floral nectar properties are also consistent with specialisation for pollination by sunbirds. Butterflies feed on the nectar of S. puniceus, but seldom contact the reproductive structures, likely limiting their effectiveness for pollen transfer. Selective exclusion of larger visitors, including birds and butterflies, negatively affected fruit and seed set for both species. Controlled pollination experiments revealed that S. puniceus is self-incompatible, whereas S. membranaceus is self-compatible and can set fruit autonomously. This study reveals that these two paintbrush lilies which are considered to be closely related have divergent pollination and breeding systems despite sharing similar inflorescence architecture.
Nannochloris-like green microalgae have evidently evolved by convergent evolution and are often unidentifiable by microscopy, including transmission electron microscopy (TEM). Their relatively simple morphology conceals an extremely high phylogenetic, physiological, and ecological diversity. The use of molecular tools has revolutionized algal diversity research, including the discovery of numerous new taxa. Strains ACSSI 104 and ACSSI 144 were isolated from solonetz and chestnut non-alkali soil, respectively (Volgograd region, Russia), in August 2014. Morphological and ultrastructural characteristics, a comparison of reproduction types and habitats, and the difference of the 18S rRNA gene and ITS2 secondary structure of the studied strains allowed us to propose a new genus—Edaphochloris A.Temraleeva, E.Krivina & O.Boldina, gen. nov. with type species—E. andreyevii A.Temraleeva, E.Krivina & O.Boldina, sp. nov. The new genus differed from the closely related Nannochloris-like genera through cell shape and size, chloroplast type, reproduction type, habitat, and value of genetic distances.
A molecular systematic study of Globba section Nudae (Zingiberaceae) using ITS and matK sequences identifies three major clades, Globba subsection Nudae, G. subsection Mediocalcaratae and a new subsection, Globba subsection Pelecantherae, which is described here. The two species belonging in this subsection, Globba pelecanthera and Globba securifer, which are both new, are described. Rectangular anther appendages are reported in Globba for the first time. Evidence of hybridisation is given. The morphological characters of the flowers, which are likely to be important in pollination, are discussed.
Nothapodytes (Icacinaceae) is a genus of seven to eleven evergreen or deciduous tree species distributed in tropical Asia from India to Japan. Nothapodytes nimmoniana sensu lato is the most widespread species of the genus, being reported sporadically throughout South Asia, Southeast Asia, Taiwan, and Japan’s southwest islands. Nothapodytes amamianus was recently described from Amami-oshima, Japan, the northeastern edge of this widespread species’ range. However, the phylogenetic distinction between these two species has yet to be explored. Here we present an analysis of molecular species delimitation to test the morphology-based taxonomic hypothesis currently used to differentiate the two species. The results clearly show that N. nimmoniana sensu lato comprises two species, one in India and the other in Taiwan and Japan, including N. amamianus, requiring a reassessment of the morphological traits hitherto used to define the former and distinguish it from the latter in East Asia. Based on the taxonomic history of the taxa and rules of nomenclature, the name N. nimmoniana is retained for the former. We propose a new combination, N. insularis, for the latter. Longitudinal intraspecific geographic structure is highlighted as an apparent indicator of further hidden diversity in India’s Western Ghats.
Previous molecular phylogenetic investigations of Apiaceae tribe Pimpinelleae have focused primarily on its largest genus Pimpinella and its closest allies. The monophyly and phylogenetic placements of five Iranian genera of the tribe have not been addressed sufficiently (Aphanopleura, Demavendia, Haussknechtia, Psammogeton, and Zeravschania). To examine relationships, a nrDNA ITS matrix including 169 accessions representing 49 genera of Apiaceae (including 10 Iranian taxa not analyzed previously) and a cpDNA rps16 matrix containing 37 accessions representing 24 genera of the family, representing the greatest sampling to date of the aforementioned genera, were subjected to phylogenetic analyses using Bayesian inference and maximum parsimony methods. The trees obtained showed a close affinity among the examined species of Aphanopleura, Psammogeton and several species of Trachyspermum. Neither Aphanopleura nor Psammogeton resolved as monophyletic, and A. leptoclada allied with Pimpinella. The genera Demavendia, Haussknechtia and Zeravschania also comprised a well-supported clade, with Demavendia and Haussknechtia (in the ITS trees) arising from within a paraphyletic Zeravschania. To recognize monophyletic genera, one new combination is proposed in Pimpinella and six new combinations are proposed in Psammogeton. A broader circumscription of Zeravschania to include Demavendia and Haussknechtia may also be warranted, but must await further study.
Colobanthus (23 species) and Sagina (30–33 species) together are sister to Facchinia. Whereas Facchinia is distributed in western Eurasia, Colobanthus is almost exclusively distributed in the Southern Hemisphere, and Sagina is distributed in both hemispheres with the highest species diversity in western Eurasia. We examined: 1. Whether Sagina and Colobanthus are monophyletic sister genera, 2. Where the two genera originated and how many times dispersal between hemispheres occurred, and 3. Which colonization routes between hemispheres were taken. We reconstructed the phylogeny of Colobanthus and Sagina using nuclear ribosomal internal transcribed spacer (ITS) and two plastid spacers (cpDNA) of altogether 158 ingroup samples of 45 species, and performed molecular dating and ancestral area reconstructions. Sagina and Colobanthus were confirmed as monophyletic sister genera. Biogeographical reconstructions based on ITS and cpDNA showed that Sagina reached the Southern Hemisphere in Australasia or in Africa. For Colobanthus, patterns were less clear and less well-supported: ITS showed Australasia as the region of entry, but cpDNA implied that the Southern Hemisphere may have been entered in America. The extant distributions and the biogeographical histories of Colobanthus and Sagina show both similarities and dissimilarities. This illustrates that biogeographical histories, even of closely related and ecologically very similar lineages, can be highly idiosyncratic.
Non-papilionate and actinomorphic flowers have evolved independently in Papilionoideae, and few ontogeny studies are available about them. The objective of the present study was to better understand the ontogenetic processes that result in papilionate and non-papilionate flowers in a sister group of the Pterocarpus clade. Inflorescences, flower buds and flowers of Discolobium pulchellum and Riedeliella graciliflora were analyzed by scanning electron microscopy, light microscopy and histochemistry of the secretory structures of floral organs. The differentiation of the petals is initiated by the petal standard followed by the keel petals and finally by the wing petals in Discolobium, in contrast to a unidirectional development of the petals in the corolla of Riedeliella. The order of sepals and antesepalous stamen is unidirectional in D. pulchellum and modi�fied unidirectional in R. graciliflora; however, the order of petal and antepetalous stamen initiation, stamen symmetry and early appearance of carpel are similar in both species. Hypanthium and floral nectary are present only in D. pulchellum and colleters in R. graciliflora. Glandular trichomes and idioblasts are present in both species. The presence of secretory structures is possibly related to the protection against herbivores, to pollination and pollinator’s attraction since different secondary compounds are present in reproductive structures. The development of the actinomorphic corolla of Riedeliella graciliflora has no similarity in terms of floral development to the other representatives of actinomorphic symmetry in Papilionoideae.
Pollen morphology of six species belonging to genera Ellisiophyllum and Sibthorpia (Plantaginaceae tribe Sibthorpieae) was studied using light and scanning electron microscopy. The data were analyzed in the light of the first phylogenetic analysis including all but one species of the tribe using DNA sequence data from nuclear ribosomal (ITS) and plastid trnL-F region. Pollen grains in representatives of this tribe are 3-colpate, occasionally 3-porate, suboblate to prolate; mainly medium-sized, rarely small. One major pollen type (3-colpate) is recognized in the tribe. Within this pollen type, six subtypes are distinguished based on their exine sculpture, pollen grain size, length of the apertures, and exine thickness. The obtained results confirm that pollen characters are useful for species identification. Palynomorphological data are consistent with the results of the molecular phylogenetic analyses. All studies support a sister relationship of the widespread European Sibthorpia euro-paea with the widespread South American Sibthorpia repens and a sister relationship of two insular species, the Balearic Sibthorpia africana and the Madeiran Sibthorpia peregrina. Pollen grains in the tribe Sibthorpieae have both reticulate exine sculpture characteristic for representatives of the Russelieae-Cheloneae-Antirrhineae clades of Plantaginaceae, and also nanoechinate sculpture, which is typical for the Veroniceae and Plantagineae clades of that family. Also, in Sibthorpia repens, we observe a possible transition from the colpate type to the porate type typical for taxa of Plantago and Littorella.
Pseudotulostoma is a genus described for fungi with stipitate sporocarps that have an exposed gleba and a woody, volvate base. The two species that belong to this genus (P. volvatum and P. japonicum) form unusual epigeous ascomata that are atypical among the hypogeous members of the Elaphomycetaceae. The genus was first described from the Guiana Shield and was suggested to be restricted to rainforests dominated by the ectomycorrhizal tree Dicymbe corymbosa (Leguminosae-Detarioideae). Pseudotulostoma volvatum was also later described from Colombia in association with Pseudomonotes tropenbosii (Dipterocarpaceae- Monotoidea). Here we report a new occurrence of P. volvatum that is also the first occurrence of an ectomycorrhizal Ascomycota fungus in a native host plant in Brazil. The description includes images of the macroscopic and microscopic characteristics, a discussion of the distinctive features, and phylogenetic placement using the nLSU of this fungus among Elaphomyces species. This new collection (third known location) demonstrates that P. volvatum also occurs in a white-sand forest composed of the canopy tree Aldina heterophylla (Leguminosae-Papilionoideae). Thus, we provide additional information regarding P. volvatum that expands its known distribution.
Hummingbirds in the Cerrado, the seasonal savannas in Central Brazil, visit both ornithophilous and non-ornithophilous
flowers to collect nectar, which is the main source of energy and nutrients to these pollinators. The aim of the present study
was to assess the volume, concentration, energy content and sugar composition of nectar collected from 34 hummingbirdvisited
flower species. We expect that nectar traits of non-ornithophilous species visited by hummingbirds are similar to
those of ornithophilous species. Nectar samples were collected from different plant formations in the Cerrado region at
Panga Ecological Station, Uberlândia City, Minas Gerais State, Brazil. Samples were obtained from 19 ornithophilous, 10
entomophilous and five chiropterophilous species. Nectar traits, such as volume, sugar concentration and energy content, did
not significantly differ between ornithophilous and non-ornithophilous flowers. However, about 80% of the sampled species
had sucrose-rich nectar, whereas other species, mainly chiropterophilous, had hexose-rich nectar. Overall, ornithophilous
and chiropterophilous flower nectars shared similar energy content. On the other hand, the sugar-chemical composition of
nectar from ornithophilous flowers was more similar to that of sucrose-rich entomophilous flowers. There is broad consensus
that the nectar in flowers of hummingbird-pollinated species is rich in sucrose. However, hummingbirds visit several
savanna plant species unrelated to the ornithophilous pollination syndrome. This trend indicates that hummingbirds show
plasticity in selecting plant nectar sources when feeding, mainly in resource-fluctuating environments such as the Cerrado.
Eleven native Geranium species have been reported in Japan, several of which include infraspecific taxa. Although phylogenetic analyses have been conducted using conventional methods (i.e., chloroplast fragment and ribosomal DNA sequencing), relationships at the infraspecific level have not been elucidated due to a lack of genetic polymorphisms. We collected specimens of 22 Geranium taxa from Japan and peripheral areas (e.g., mainland China, South Korea, Russia, and Taiwan), and performed detailed phylogenetic analyses using chloroplast genome sequencing and genome-wide single-nucleotide poly-morphisms. Some discrepancies were observed between the current taxonomy and the phylogenetic relationships elucidated in our analyses. The Geranium tripartitum complex was found to be paraphyletic, and Geranium onoei f. yezoense, which is synonym of Geranium reinii, was found to be more closely related to Geranium erianthum than to G. reinii. In particular, G. tripartitum var. hastatum located at intermediate position between Geranium thunbergii and Geranium wilfordii in the network analysis. Therefore, we suggest that G. tripartitum var. hastatum should be treated as an independent species, and that G. onoei f. yezoense should be transferred to G. erianthum.
The study considers the phylogenetic affinities and taxonomical placement of the previously unknown hepatic from Hengduan Mts. in Yunnan Province of China. This area is known to house a vast assemblage of peculiar and taxonomically secluded taxa of hepatics, serving as kind of storehouse of missing links in the evolution. The newly recorded taxon combines lophozioid appearance with prominent tooth in the antical side of the leaf—the feature previously observed in Cephaloziineae very rarely and in bracts only. Molecular phylogenetic reconstruction, inferred from the nuclear ITS region and the chloroplast rps4 gene, trnL-F region and trnG-intron resolved Konstantinovia gen. nov. as the closest relative of highly phylogenetically isolated monospecific genus Obtusifolium. Their joint clade is sister to the Anastrophyllaceae clade in the tree inferred from combined ITS and trnL sequences, while topology inferred from combined trnG and rps4 sequences fails to resolve its affinity within the Scapaniaceae s.l. clade. Therefore, the new family Obtusifoliaceae is introduced to accommodate these genera, and the familial classification of Cephaloziineae is discussed.
Two species of Pluteus, namely P. brunneoalbus and P. sepiicolor, from China are reported and illustrated. Pluteus brunneoalbus is described as a new species in P. sect. Celluloderma. This species is characterized by a shallowly depressed pileus, a white stipe, ellipsoid to broadly ellipsoid basidiospores 6–7 × 5–6.5 μm, the presence of few scattered cheilocystidia, the presence of mostly clavate pleurocystidia, and a cutis type pileipellis. In the phylogenetic analysis based on the internal transcribed spacer region (ITS), the new species appears as sister to P. hirtellus and P. squarrosus. In addition to the new species, another species, P. sepiicolor, is reported here as a new record for China. Molecular data support its conspecificity with a collection from Russia. Detailed morphological descriptions including illustrations of the two species from China, and their comparisons with the related taxa of Pluteus are also provided with phylogenetic placement.
Cyrtandra (Gesneriaceae), with over 800 species, is a mega-diverse genus which presents considerable taxonomic challenges due to its size. A well-sampled phylogeny of the genus across Southeast Asia has confirmed that all but one of the sections within Clarke’s 1883 genus-wide infrageneric classification are polyphyletic. It also shows that there are high levels of homoplasy in key morphological characters, although it is possible to use morphological characters to define clades in parts of the phylogenetic tree. There is some geographic structure in the phylogeny, but there is also evidence of dispersal between islands. A practical approach for tackling the taxonomy of Cyrtandra in the region, through phylogenetically informed taxonomic revisions of geographic areas, an approach which combines evidence from molecular, morphological and distribution data, is discussed. Completing our understanding of species diversity and delimitation in this genus will allow us to maximise the use of Cyrtandra as a tool for studying biogeography, speciation, diversification and conservation prioritisation in the rainforests of Southeast Asia.
Morphological and phylogenetic (nrITS barcode) analyses are conducted to clarify the taxonomic status of 10 Delphinium species (D. cuneatum, D. dictyocarpum, D. duhmbergii, D. elatum, D. litwinowii, D. pubiflorum, D. puniceum, D. sergii, D. subcuneatum, D. uralense) occurring in the South-East of European Russia. The morphometric analysis is carried out with 22 quantitative and 32 qualitative parameters. Based on all parameters, the nMDS supports the differentiation of D. puniceum, D. sergii, D. uralense and D. pubiflorum whereas other studied taxa remain undistinguished. Furthermore, the Random forest analysis and the MrBayes phylogenetic analysis of ITS sequences confirm the species status of D. puniceum belonging to D. sect. Diedropetala and D. elatum, D. uralense, D. dictyocarpum and D. pubiflorum belonging to D. sect. Delphinastrum. Finally, recursive partitioning is performed to develop the dichotomous key which can be used to identify the species of Delphinium in the study area. In conclusion, we stress that the recognition of species belonging to D. sect. Delphinastrum is hindered by the presence of numerous intermediate or hybrid forms, on the one hand, and the impact of climatic conditions on the morphological (and, specifically, taxonomically significant) traits, on the other hand.
The hyperarid Atacama Desert coast receives scarce moisture inputs mainly from the Pacific Ocean in the form of marine advective fog. The collected moisture supports highly specialized ecosystems, where the bromeliad Tillandsia landbeckii is the dominant species. The fog and low clouds (FLCs) on which these ecosystems depend are affected in their interannual variability and spatial distribution by global phenomena, such as ENSO. Yet, there is a lack of understanding of how ENSO influences recent FLCs spatial changes and their interconnections and how these variations can affect existing Tillandsia stands. In this study, we analyze FLCs occurrence, its trends and the influence of ENSO on the interannual variations of FLCs presence by processing GOES satellite images (1995-2017). Our results show that ENSO exerts a significant influence over FLCs interannual variability in the Atacama at ~ 20°S. Linear regression analyses reveal a relation between ENSO3.4 anomalies and FLCs with opposite seasonal effects depending on the ENSO phase. During summer (winter), the ENSO warm phase is associated with an increase (decrease) of the FLCs occurrence, whereas the opposite occurs during ENSO cool phases. In addition, the ONI Index explains up to ~ 50 and ~ 60% variance of the interannual FLCs presence in the T. land-beckii site during summer and winter, respectively. Finally, weak negative (positive) trends of FLCs presence are observed above (below) 1000 m a. s. l. These results have direct implications for understanding the present and past distribution of Tillandsia ecosystems under the extreme conditions characterizing our study area.
Despite the extensive area covered by the coastal Atacama fog Desert (18–32° S), there is a lack of understanding of its most notorious characteristics, including fog water potential, frequency of fog presence, spatial fog gradients or fog effect in ecosystems, such as Tillandsia fields. Here we discuss new meteorological data for the foggiest season (July–August–September, JAS) in 2018 and 2019. Our meteorological stations lie between 750 and 1211 m a. s. l. at two sites within the Cordillera de la Costa in the hyperarid Atacama (20° S): Cerro Oyarbide and Alto Patache. The data show steep spatial gradients together with rapid changes in the low atmosphere linked to the advection of contrasting coastal (humid and cold) and continental (dry and warm) air masses. One main implication is that fog presence and fog water yields tend to be negatively related to both distance to the coast and elevation. Strong afternoon SW winds advect moisture inland, which take the form of fog in only about 6% of the JAS at 1211 m a. s. l., but 65% at 750 m a. s. l. on the coastal cliff. Although sporadic, long lasting fog events embrace well-mixed marine boundary layer conditions and thick fog cloud between 750 and 1211 m a. s. l. These fog events are thought to be the main source of water for the Tillandsia ecosystems and relate their geographic distribution to the lowest fog water yields recorded. Future climate trends may leave fog-dependent Tillandsia even less exposed to the already infrequent fog resulting in rapid vegetation decline.
The interplay between plants and soil drives the structure and function of soil microbial communities. In water-limited environments where vascular plants are often absent and only specialized groups of rootless plants grow, this interaction could be mainly asymmetric, with plants supporting nutrients and resources via litter deposition. In this study, we use observational approaches to evaluate the impact of local distribution of Tillandsia landbeckii across elevation on soil bacterial community structure and composition in the Atacama Fog Desert. Tillandsia landbeckii is a plant without functional roots that develops on meter-scale sand dunes and depends mainly on marine fog that transports resources (water and nutrients) from the Pacific Ocean. Our data show that soil bacterial abundance, richness, and diversity were significantly higher beneath T. landbeckii plants relative to bare soils. However, these differences were not significant across T. landbeckii located at different elevations and with different input of marine fog. On the other hand, bacterial community composition was significantly different with T. landbeckii plants across elevations. Further, samples beneath T. landbeckii and bare soils showed significant differences in bacterial community composition. Around 99% of all operational taxonomic units (OTUs) were recorded exclusively beneath T. landbeckii, and only 1% of OTUs were observed in bare soils. These findings suggest that the presence of T. landbeckii promotes significant increases in bacterial abundance and diversity compared with bare soils, although we fail to demonstrate that local-scale changes in elevation can affect patterns of soil bacterial diversity and abundance beneath T. landbeckii.
Dioecy, the separation of sex at the individual level, evolved in angiosperms from hermaphroditic ancestors. One of the postulated evolutionary pathways is by way of the gynodioecious stage, i.e., the coexistence of female and hermaphroditic individuals. In a morphologically gynodioecious species, Daphne jezoensis., seed fertility in hermaphrodites is limited compared to that of females, indicating that its sexual system is close to dioecy. The aim of this study was to clarify whether the gynodioecy in this species is a stable sexual system or a transitional state leading to dioecy. We evaluated variations in the degree of pollen limitation, sexual and mating systems, floral morphology, sex ratio, and the genetic structure of 14 populations across the species’ distribution range in Japan. Sexual systems were similar among populations throughout the distribution range although the southernmost populations had unique genetic structures to some extent. Hermaphrodites were commonly self-compatible, but their fruiting capacity was low in every population. This suggests that gynodioecy composed of females and hermaphrodites having low seed fertility is a consistent sexual system in D. jezoensis. Low seed fertility in hermaphrodites throughout the distribution range suggests that this sexual system is not necessarily a transitional state from gynodioecy to dioecy if occasional seed production in hermaphrodites has any advantage. One possible ecological advantage for the maintenance of hermaphrodites is that seed production by autonomous self-pollination may be beneficial in the colonization process after long-distance seed dispersal.
The mycoheterotrophic genus Thismia shows a great number of structural and ecological traits which are rare or unique for angiosperms. Pollen morphology of this genus is still poorly known. Pollen of Thismia was reported to be porate with one to several pores. Position of the pores is unknown, and therefore, the pollen type has not been established to date. Information on sporoderm structure in the genus is scarce, as high-quality images of pollen grains are available for several species only. In our comprehensive investigation of pollen morphology of Thismia, we involved nine Asian species of the genus and employed an integrative approach, which included data from light microscopy, scanning electron microscopy and transmission electron microscopy. All studied species were shown to possess monoporate pollen of asymmetric-elliptic planoconvex shape. Using TEM investigation of immature anthers, we demonstrated that pollen grains are organized in tetragonal tetrads, and the pore occupies an equatorial position. We argue that Asian species of Thismia along with Burmannia from the same order Dioscoreales are the only known lineages of seed plants with a single equatorial aperture. The sporoderm surface is psilate or perforate with perforations of various size and density in the studied species. We discuss the interspecific variation of sporoderm morphology in the light of the phylogenetic relationships between Asian species of Thismia. We demonstrate that the pollen morphology of Thismia fails to conform to the idea of entomophily, which is believed to prevail in this genus. Finally, we describe an unexpected striking difference in sporoderm structure between the specimens belonging to T. javanica species group.
Species distribution modeling and assessment of the possible current conservation status for loma-forming Tillandsia purpurea Ruiz & Pavón in Peru were performed. This species is considered an epiarenic species that lives under hyperarid conditions, where its main source of water and nutrients comes from the fog of the Pacific coast. For the distribution modeling, 63 records from different sources of information were used, including a current field survey. Locations covered the whole range of the species´ known distribution along the Peruvian coast, and respective elevations lie between 0 and 2000 m a. s. l. Likewise, 27 environmental variables were used, including bioclimatic and eco-geographical ones, to determine the corresponding ecological niche and compare between actual and potential distribution. The conservation status was estimated according to the criteria recommended by the IUCN red list. High probability values were obtained predicting the occurrence of T. purpurea and describing respective environmental conditions such as altitudinal distribution between 400 and 1200 m and predominant southwest exposure of habitats. The conservation status of T. purpurea was supposed between "least concern" and near threatened, recommending that this species should be placed into the latter category and considering recurrent threats by direct anthropogenic impact and climate change verified during the field surveys.
In this paper we review the fragmentary fossil pollen record of Hamamelidaceae which extends back to the middle Eocene until the Early Pleistocene in the Iberian Peninsula. Records of fossil palynomorphs related to Hamamelidaceae are very scarce in the European Cenozoic, in part due to difficulty in confident identification at a generic or even familial rank. The present review contributes to improving the accuracy of identification of Cenozoic Hamamelidaceae in standard palynological studies, which should help trace its poorly understood fossil and evolutionary history. The review of all published Iberian records indicates a considerable generic diversity. At least four genera can be confidently identified. The examination of new material from the Oligocene of north-west Spain has led to the formal description of three new fossil pollen genera that are related to extant genera currently restricted geographically to Asia: Disanthuspollenites, Embolantherapollenites and Parrotiapollenites. Based on SEM analysis, a new combination of the fossil species Tricolpopollenites indeterminatus, traditionally used to designate fossil pollen related to Hamamelidaceae in Europe, is proposed. Additionally, we discuss the occurrence of pollen forms that can be tentatively attributed to Corylopsis and Fothergilla.
The morphological variation and cytotype diversity were investigated among Central European populations traditionally recognized as Dactylorhiza fuchsii, recently incorporated in D. maculata s.l. Flow cytometry was employed to assess the ploidy levels of 738 individuals from 77 localities and multivariate morphometrics for a total of 531 individuals from 27 localities. Three ploidy levels were found: diploid (2n = 2x = 40), DNA-triploid and tetraploid (2n = 4x = 80). Whereas diploids and tetraploids often occurred as pure-cytotype populations, individuals of DNA-triploids always co-occurred with at least one of the other cytotypes. Qualitative morphological traits were inferred to be the most important drivers of morphological variation among the investigated plants, with the most striking differences in flower colouration and leaf spotting. The combination of morphological and cytological characters enabled to delimit two separate groups of populations. The first corresponded to D. maculata subsp. fuchsii with morphologically indistinguishable diploid, DNA-triploid and tetraploid individuals, sometimes occurring in mixed-ploidy populations. A complex geographical pattern of cytotype distributions was observed, with diploids scatteredly occurring throughout Central Europe except for Bohemian Massif, which was dominated by tetraploids. The other group of populations represented newly described in this study D. maculata subsp. sooana, subsp. nova, morphologically well-defined and strictly diploid taxon with a restricted geographical range, occurring in the Western Carpathians. A new combination for a hybrid taxon D. × dinglensis nothosubsp. smitakii, comb. nova (= D. maculata subsp. sooana × D. majalis subsp. majalis), was also proposed.
Genetic variation determines the evolutionary potential of a species and is vital for fully understanding the evolution of a species, as well as for developing optimal conservation strategies. Horsfieldia tetratepala is classified as a Plant Species with Extremely Small Populations (PSESP) in China where it is an economically important rainforest tree, but it has declined sharply, mainly caused by habitat destruction and is now an endangered, narrow endemic. Effective conservation strategies for H. tetratepala are required urgently, but limited information exists about its genetic diversity. Accordingly, restriction site-associated DNA sequencing (RAD-seq) was used to sequence sixty-three H. tetratepala trees covering ten isolated populations to assess genomic diversity and population structure. The survey generated 8103 high-quality SNPs, analysis of which revealed low genetic diversity and moderate genetic differentiation among populations. However, Bayesian clustering of the sampled H. tetratepala populations produced two genetic clusters, though with some populations from Guangxi and Yunnan intermixed. Because of the increase in habitat fragmentation and human disturbance, conservation priority should be placed on populations with higher genetic variation (e.g., BB, TKH, DWS, and GLQ), allowing the formulation of more effective conservation strategies for this PSESP species.