Article

Evidence for Moth and Butterfly Pollination in Gladiolus (Iridaceae-Crocoideae)

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Abstract

Pollination strategies of Gladiolus. one of the largest genera of the monocot family Iridaceae, are unusually diverse, and include various bee species, foraging either for nectar or for pollen, passerine birds, long-proboseid flies foraging for nectar. hopliine beetles that use the flowers primarily as sites for assembly, and Lepidoptera. pollination by insects of this order comprises two entirely different sets of pollinators, night-flying moths (Noctuidae or Sphingidae) and butterflies (evidently only one species of Satyridae). These lepidopteran-pollinated flowers have quite different floral adaptations, and both types are specialist systems, although moth flowers may be pollinated by a range of different moths. In Gladiolus moth-pollinated flowers are usually large, long-tubed and pale-colored. or mottled dull purple to brown. are usually richly scented, often open fully only at night, and produce relatively concentrated nectar that is sucrose-rich. Butterfly flowers, in contrast, are fully open during the day, close partially or completely at night, are often bright crimson to scarlet, usually with prominent white splashes on the lower tepals, but are also large, have a lone tube, and produce quantities of relatively dilute nectar. either sucrose-rich or hexose-rich. Comparing the pollination systems of related species, we infer that night-flying moth pollination arose 6 times in the genus, whereas butterfly pollination arose 3 times in the 165 species of southern Africa, and that the two lepidopteran pollination systems in Gladiolus arose quite independently of one another.

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... The novelty of the finding of this study of hawkmoth pollination in Erica cylindrica may reflect the relative difficulty involved in documenting nocturnal insect pollinators (e.g. Amorim et al., 2014;Johnson et al., 2020a;Wasserthal, 1997) but it may also reflect genuine rarity of hawkmoth pollination in the CFR (but see Goldblatt et al., 2005;Goldblatt and Manning, 2002a;Van der Niet et al., 2015), possibly due to the absence of suitable host plants for the larval stages of the life cycle (cf. Cottrell, 1985;Johnson, 1997;Johnson and Raguso, 2016). ...
... Nectar concentration and composition of E. cylindrica are consistent with sphingophily (Baker and Baker, 1983;Goldblatt and Manning, 2002a;Johnson and Raguso, 2016), although the nectar volume is exceptionally small, especially in comparison to larger flowers known to be specialized for hawkmoth pollination . However, nectar volumes produced in hawkmoth-pollinated species are Shading indicates 95% confidence intervals for reflectance measurements. ...
... highly variable, and higher volumes have been interpreted as evidence for selection to promote preferential feeding by long-tongued pollinators, which may be more important where competition for hawkmoth pollination is greater than it is in the CFR Sazatornil et al., 2016). The sugar composition found for E. cylindrica matches that reported previously for the species (Barnes et al., 1995) and the sucrose:hexose ratio of 0.7 is consistent with sucrose-rich nectars (sucrose:hexose ratio 0.5-1 (Baker and Baker, 1983)) typically associated with hawkmoth pollination (Kelber, 2003) and thought to reflect the high energetic requirements of hovering pollinator behaviour (Goldblatt and Manning, 2002a;Proctor et al., 1996). ...
Article
The predictive power of pollination syndromes has been demonstrated for many South African plant species with specialized pollination systems, but has rarely been tested in the florally diverse genus Erica. Here we evaluate the hypothesis that Erica cylindrica is moth-pollinated, based on its tubular, pale, and strongly scented flowers. Pollinator observations revealed exclusive nocturnal flower visitation by several hawkmoth species, and assessment of pollen loads confirmed that two hawkmoth species carried Erica pollen grains on their proboscises. Floral scent showed no clear periodicity in emission, but was dominated by benzenoid scent compounds including benzaldehyde, benzyl alcohol, benzyl acetate, and eugenol that are known to elicit antennal responses in hawkmoths. The pale cream flower colour was characterized by uniform reflectance across the human-visible light spectrum and a small secondary peak in the UV region. The volume of nectar produced was small, but the intermediate sugar concentration and sucrose:hexose ratio of 0.7 are consistent with hawkmoth pollination. More than three-quarters of flowers in an inflorescence are oriented upwards, which is highly unusual among South African ericas but has been shown to be adaptive in other hawkmoth-pollinated flowers. Anther-ring disruption indicated that at least 62% of flowers received visits and was associated with pollen deposition in 68% of visited flowers, suggesting that visitors are effective pollinators. Our study provides evidence for hawkmoth pollination of an Erica species, a system hitherto rarely recorded in Ericaceae. Several floral traits are consistent with the hawkmoth pollination syndrome, but further work is required to confirm the functional significance of these traits and the level of specialization in this hawkmoth pollination system.
... Thus, flowers pollinated by diurnal insects or birds open for all or part of the day, whereas those pollinated by night-flying moths usually open in the late afternoon or evening. Especially notable are species of Gladiolus and Hesperantha (Goldblatt and Manning, 2002;Goldblatt et al., 2004a), which show particularly complex opening and closing patterns. In Hesperantha diurnal opening is usually restricted to part of the day, morning or afternoon, whereas evening flowers open at specific times before or after sunset and close again in early or late evening. ...
... data). Among moth-pollinated Gladiolus species examined for fragrance chemistry, linalool is the dominant compound in G. maculatus, G. recurvus and G. tristis, whereas eugenol dominates in G. liliaceus (Goldblatt and Manning, 2002). Similarly, the floral fragrance of Tritoniopsis nervosa, which is pollinated by sphinx moths, is also rich in linalool (Manning and Goldblatt 2005). ...
... Large butterfly flowers (Fig. 5). Restricted to just a few species in the genera Crocosmia, Freesia, Hesperantha, Gladiolus and Tritoniopsis (Table 1), flowers adapted for pollination by large papilionid or satyrid butterflies typically have a red to orange, rarely yellow or purple perianth, sometimes with white splashes on the lower tepals, and a relatively long, slender perianth tube (Goldblatt and Manning, 2002). Flowers are either flag or brush types ( fide Faegri and van derPijl, 1971). ...
Article
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Seventeen distinct pollination systems are known for genera of sub-Saharan African Iridaceae and recurrent shifts in pollination system have evolved in those with ten or more species. Pollination by long-tongued anthophorine bees foraging for nectar and coincidentally acquiring pollen on some part of their bodies is the inferred ancestral pollination strategy for most genera of the large subfamilies Iridoideae and Crocoideae and may be ancestral for the latter. Derived strategies include pollination by long-proboscid flies, large butterflies, night-flying hovering and settling moths, hopliine beetles and sunbirds. Bee pollination is diverse, with active pollen collection by female bees occurring in several genera, vibratile systems in a few and non-volatile oil as a reward in one species. Long-proboscid fly pollination, which is apparently restricted to southern Africa, includes four separate syndromes using different sets of flies and plant species in different parts of the subcontinent. Small numbers of species use bibionid flies, short-proboscid flies or wasps for their pollination; only about 2 % of species use multiple pollinators and can be described as generalists. Using pollination observations for 375 species and based on repeated patterns of floral attractants and rewards, we infer pollination mechanisms for an additional 610 species. Matching pollination system to phylogeny or what is known about species relationships based on shared derived features, we infer repeated shifts in pollination system in some genera, as frequently as one shift for every five or six species of southern African Babiana or Gladiolus. Specialized systems using pollinators of one pollination group, or even a single pollinator species are the rule in the family. Shifts in pollination system are more frequent in genera of Crocoideae that have bilaterally symmetric flowers and a perianth tube, features that promote adaptive radiation by facilitating precise shifts in pollen placement, in conjunction with changes in flower colour, scent and tube length. Diversity of pollination systems explains in part the huge species diversity of Iridaceae in sub-Saharan Africa, and permits species packing locally. Pollination shifts are, however, seen as playing a secondary role in speciation by promoting reproductive isolation in peripheral, ecologically distinct populations in areas of diverse topography, climate and soils. Pollination of Iridaceae in Eurasia and the New World, where the family is also well represented, is poorly studied but appears less diverse, although pollination by both pollen- and oil-collecting bees is frequent and bird pollination rare.
... Pouco se sabe sobre a biologia reprodutiva das espécies brasileiras de Iridaceae (Vitali et al., 1995;Freitas & Sazima 2003a, b;Santos et al., 2016), no entanto, destacam-se vários trabalhos realizados com este enfoque no continente africano (Goldblatt et al., 1995;Goldblatt et al., 1998;Steiner, 1998;Goldblatt Goldblatt & Bernhardt, 1999;Goldblat & Manning, 2000;Wesseling & Arnold, 2000;Goldblatt et al., 2001;Goldblatt & Manning, 2002;Goldblatt et al., 2005;Goldblatt & Manning, 2006). A grande maioria das espécies de Iridaceae oferecem néctar e pólen como principais recursos florais aos visitantes, enquanto alguns oferecem óleos não voláteis produzidos por elaióforos tricomáticos. ...
... As flores permanecem receptivas apenas no período da manhã e, por volta das 17:00 h, a flor entra em processo de senescência com as tépalas retraindo-se. Por estas características as flores são consideradas efêmeras, o que é comum a muitos outros gêneros de Iridaceae, sendo esta considerada uma condição ancestral na família (Goldblatt et al., 2002;Goldblatt & Manning, 2006). Figura 1. Neomarica northiana: a-Habitus evidenciando crescimento clonal através da folha vegetativa que emite a inflorescência; b-fruto; c-corte longitudinal do fruto; d-semente; einfrutescência; f-Habitus evidenciando a emissão de uma inflorescência; g-tépala externa; h-tépala interna; i-flor em pós-antese; j-vista superior do tubo estilar; l-ovário em corte transversal; m-estruturas reprodutoras; n-detalhe do estigma e das cristas do estilete; o-flor. ...
Article
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Este trabalho teve como objetivo estudar a biologia reprodutiva de Neomarica northiana (Schneev) Sprague (Iridaceae), erva perene que ocorre nas restingas do estado do Rio de Janeiro. A flor desta espécie apresenta três unidades funcionais de polinização denominada “meranthia”. O recurso floral oferecido aos polinizadores é a substância lipídica exsudada na base das tépalas. Análise de cromotografia gasosa das tépalas indicou a presença de limoneno. As flores de N. northiana são polinizadas exclusivamente por abelhas poliléticas de grande porte, Xylocopa sp.. Neomarica northiana é autocompatível. A produção de frutos por polinização natural foi maior do que a produção por polinização manual cruzada. A taxa de fecundidade é de 0,47. Neomarica northiana apresenta crescimento clonal que pode ocorrer de duas formas distintas, por meio do caule rizomatoso e por meio de bulbilhos formados na axila das brácteas.AbstractThe objective of this research was to evaluate the reproductive biology of Neomarica northiana (Iridaceae), a perennial herb that occurs in the Atlantic Coast restingas (humid subtropical broadleaf forest) of the state of Rio de Janeiro. Each flower of this species has three functional pollinating units called “meranthia”. The main floral resource provided to bees by Neomarica northiana is a lipid substance exuded at the base of the tepals. Gas-chromatographic analysis of tepal samples revealed the presence of limonene. Flowers of N. northiana are pollinated exclusively by large bodied species of bees (Xylocopa sp.). Fruit production from natural pollination is higher than from manual pollination. The fecundity rate is 0.47. Neomarica northiana has clonal growth, which may occur by means of the rhizomatous stem, which produces offshoots close to one another; or by means of axillary bulbils.
... The actinomorphic flowers, the corolla color ranging from white to cream, and shallow tube, presence of nectar and pollen production found in P. duckei are traits that fit the Melittophily syndrome. These floral characteristics are also in agreement with descriptions by Richards (1997), Machado et al. (1998) and Goldblatt & Manning (2002) for pollination by small bees. ...
... The floral traits of Pagamea duckei and that of most species in this genus, like the tubular corolla with free spreading lobes covered with hairs that limits the nectar robbing by small insects, and the nectar production itself, are in agreement with Psycophily (Faegri & Van der Pijl 1979), which has been reported for other Rubiaceae (Castro & Oliveira 2002, Goldblatt & Manning 2002, Fenster et al. 2004. Flies, however, were not observed visiting the flowers of P. duckei. ...
Article
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The floral biology, pollination and breeding system of Pagamea duckei Standl. (Rubiaceae) were studied at the Reserva Biológica da Campina, Manaus, Amazonas, Brazil. Floral morphology suggested that P. duckei is a distylous species. However, crossing experiments revealed that it is functionally dioecious. The flowers are actinomorphic, yellowish, produce nectar and a sweet odor, which is more intense in the morning. Anthesis started in the morning between 5.00 and 6.00 AM and extended until dusk, when the corolla tube abscissed. The flowers were visited mostly by bees of the genus Melipona. Pagamea duckei is not agamospermic and thus needs pollen vectors for effective pollination. The results of this study strengthen the idea that, in Pagamea, species with distylous flower morphology are actually functionally dioecious.
... Observing plants that express pollination syndromes to predict moth visitation has been employed with success. Goldblatt and Manning (2002), for example, examined 21 species of Gladiolus of different floral characters (e.g. colour, scent, and shape) and found that sphingids (e.g. ...
... For example, Darwin (1888) found that Agrotis, Hadena, Acontia, Leucania, Noctua, Heliothis and Lithosia each visited various species of orchids. The genus Zygaena (Zygaenidae) includes many well-known flower visitors (Norris, 1936;Hahn & Brühl, 2016), and moths in the genus Cucullia are often listed as flower visitors (Groman & Pellmyr, 1999;Goldblatt & Manning, 2002;Makholela & Manning, 2006). Two species of Deltophora are exclusive pollinators of two species of plants in the genus Phyllanthus (Luo et al., 2011). ...
... Observing plants that express pollination syndromes to predict moth visitation has been employed with success. Goldblatt and Manning (2002), for example, examined 21 species of Gladiolus of different floral characters (e.g. colour, scent, and shape) and found that sphingids (e.g. ...
... For example, Darwin (1888) found that Agrotis, Hadena, Acontia, Leucania, Noctua, Heliothis and Lithosia each visited various species of orchids. The genus Zygaena (Zygaenidae) includes many well-known flower visitors (Norris, 1936;Hahn & Brühl, 2016), and moths in the genus Cucullia are often listed as flower visitors (Groman & Pellmyr, 1999;Goldblatt & Manning, 2002;Makholela & Manning, 2006). Two species of Deltophora are exclusive pollinators of two species of plants in the genus Phyllanthus (Luo et al., 2011). ...
Article
1. The natural history of pollination has been studied for centuries and is well documented for diurnal insect species, such as bees and butterflies, but less so for moths. There are notable cases of pollination systems among moths, but given their enormous diversity and primarily nocturnal habits, the role of moths as flower visitors is poorly understood. One potential issue with studying moth‐pollination systems is determining which approach to use in order to acquire data and reveal pollination patterns and dynamics. Based on reports from the literature and the authors' own research, this paper outlines eight approaches that can be employed to search for patterns of flower visitation by moths. 2. The outlined approaches include searching the internet and online databases, sampling ecosystems, monitoring specific flowers, using artificial baits and floral scent lures, using moth phylogeny, proboscis morphology, and DNA and environmental DNA metabarcoding, which are supplemented with a brief description of the techniques and examples for each approach. 3. Each approach has the potential to increase researchers' knowledge of associations between moths and the flowers that they visit, but their relative strengths and limitations are dependent on scope, efficacy of application, technical expertise, and level of effort. 4. Each of these approaches, alone or in combination, are likely to be useful in the search for novel information on the natural history of flower visitation by moths and other potential pollinators. Recent reviews of moth pollination have highlighted the importance of moths as plant mutualists, yet the number of demonstrated pollinating moths is relatively small given their enormous diversity. Feeding behaviors for most moths are unknown, and determining which species are likely flower visitors is overwhelming. This paper outlines eight systematic approaches for searching for flower‐visiting moths. Each approach has the potential to identify novel plant–pollinator interactions.
... Insect diversity is high and there is also an exceptional diversity of pollination systems (Rebelo 1987;, some of which are highly specialised Johnson 2004). These include: ornithophily (Rebelo et al. 1984;, therophily (Weins et al. 1983;Johnson et al. 2001), pollination by long-proboscid flies (Goldblatt & Manning 2000b), pollination by oil-collecting bees , beetle pollination (Picker & Midgley 1996), pollination by butterflies and moths (Goldblatt & Manning 2002b), and pollination by the Cape honeybee (Apis mellifera capensis), which is specifically adapted to survive the cold wet winters of this region (Hepburn & Crewe 1990;Hepburn & Guillarmod 1991). Ornithochory is another interesting animal-plant interaction that is common in strandveld where there are many fleshy-fruited plant species and frugivorous birds ; it is also frequent in renosterveld, especially in fire-safe areas such as termitaria which harbour thicket species . ...
... The pollination of G. longicollis has been well characterized (Goldblatt & Manning, 1999Alexandersson & Johnson, 2002;Anderson et al., 2010). The long-tongued hawkmoth Agrius convolvuli (tongue length, 99 mm) is the primary pollinator of the long-tubed morph (Alexandersson & Johnson, 2002), whereas a number of short-tongued hawkmoths (tongue lengths, 31-41 mm; Alexandersson & Johnson, 2002) have been observed pollinating the shorttubed morph (Goldblatt & Manning, 2002;Anderson et al., 2010;P. Rymer & S. Johnson, pers. ...
Article
• Pollinators, as gene flow vectors and selection agents, play a central role in the origin and maintenance of floral variation in natural populations. However, it is debatable whether pollination alone can complete the speciation process in sympatry. • Mating patterns and phenotypic selection on floral traits were characterized over two flowering seasons for sympatric corolla tube length morphs of the hawkmoth-pollinated iris Gladiolus longicollis. A mating model with genetic and spatial-temporal predictors was developed to identify seed paternity. A multivariate analysis was used to estimate selection on correlated floral traits based on maternal and paternal fitness. • Mating patterns among floral morphs were density dependent, resulting in assortative mating at low plant densities, and random mating among morphs at high densities. Weak disruptive selection on tube length was detected in one season for maternal fitness. Plant height was under opposing directional selection for maternal (+) and paternal (-) fitness functions. • These results indicate that G. longicollis morphs will introgress rather than diverge towards speciation. The lack of strong assortative mating, particularly at high densities, is predicted to result in the loss of rare morphs within populations, and indicates that spatial and temporal co-occurrences of floral morphs are evolutionarily unstable.
... Insect diversity is high and there is also an exceptional diversity of pollination systems (Rebelo 1987;, some of which are highly specialised Johnson 2004). These include: ornithophily (Rebelo et al. 1984;, therophily (Weins et al. 1983;Johnson et al. 2001), pollination by long-proboscid flies (Goldblatt & Manning 2000b), pollination by oil-collecting bees , beetle pollination (Picker & Midgley 1996), pollination by butterflies and moths (Goldblatt & Manning 2002b), and pollination by the Cape honeybee (Apis mellifera capensis), which is specifically adapted to survive the cold wet winters of this region (Hepburn & Crewe 1990;Hepburn & Guillarmod 1991). Ornithochory is another interesting animal-plant interaction that is common in strandveld where there are many fleshy-fruited plant species and frugivorous birds ; it is also frequent in renosterveld, especially in fire-safe areas such as termitaria which harbour thicket species . ...
Article
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ENGLISH ABSTRACT: The South African Cape lowlands have been severely transformed and reduced to fragments embedded in matrices of various activities. With the need to prioritise conservation efforts, information on the conservation worthiness and management of these fragments is required. This study aimed to better understand how fragmentation affects the Cape lowland vegetation patterns and dynamics and more specifically, to determine if, and if so to what extent these fragments contribute to regional plant diversity and more importantly their functionality. The novel approach adopted focused on plant functional traits, which are better predictors of ecosystem response to global change than individual species. Species were sampled at four scales in four sites of decreasing sizes, including: a mainland and three fragments of three Cape lowland vegetation types i.e. Atlantis Sand Fynbos (ASF), Swartland Shale Renosterveld (SSR) and Langebaan Dune Strandveld (LDS). Traits such as dispersal, pollination, breeding mode and longevity were selected based on relevance to species’ and plantfunctional types’ (PFTs) responses to fragmentation. The findings revealed different effects on species richness and PFTs. The effect of reduced patch size on species richness was more evident in ASF where fragments below 600 ha had significantly fewer species than the mainland. This effect was not unequivocal in SSR and LDS due to several confounding factors (notably the grazing history of the sites). The SSR fragment grazed by indigenous herbivores had significantly more species than the ungrazed sites. Also, the largest LDS fragment grazed by livestock had significantly more species than the ungrazed mainland, indicating that grazing rather than fragment size influences species richness, although the smallest fragments of these two vegetation types had significantly fewer species than the larger fragments. Species turnover and complementarity were high for all three vegetation types, reflecting the degree of habitat heterogeneity and high contribution of beta diversity to overall gama diversity. The effect of reduced patch size was higher on PFT diversity than on PFT richness, with Langebaan Dune Strandveld where habitat fragmentation was more recent being the least affected of the three vegetation types. This indicates a degree of functional redundancy in the Cape lowlands, which is important for ecosystem resistance and resilience. The ASF mainland and the largest fragment had higher PFT diversity than the medium-sized and the smallest fragments; the mainland had also higher PFT diversity than all the fragments combined. Similarly, the smallest SSR fragment had significantly lower PFT diversity and richness than the other sites. The grazed SSR fragment had higher PFT richness and diversity than the ungrazed mainland and smallest fragment, indicating the role of grazing in maintaining renosterveld vegetation. The PFTs absent from the different sites were mostly short-distance dispersed dioecious and non-dioecious species, and some with highly specialised pollination systems. This suggests that dispersal and pollination are vital functional attributes for the persistence of the studied fragmented ecosystems. Habitat fragmentation effects plant community composition and ecological functions in the Cape lowlands, a conclusion supported also by the revealed significant trait-convergence and divergence assembly patterns. These communities result from various fragmentation filters that operate at different spatial-temporal scales and selecting species with suitable responses. All three vegetation types are susceptible to fragmentation, albeit at varying degree. The fragmentation effect was confounded by the sampling and temporal scales, the nature of disturbance regime, and the traitmediated differences in species’ response. The role of the surrounding matrix on fragment connectivity and gene flow appears to be of crucial importance, hence mitigation measures focusing on improving connectivity between patches, monitoring threatened taxa, and promoting dispersal and pollination have been recommended. AFRIKAANSE OPSOMMING: Suid-Afrika se Kaapse laagland het dramaties verander en weggekwyn tot fragmente wat in matrikse van verskeie bedrywighede veranker is. Gedagtig aan die voorkeuraandag wat bewaringspogings tans geniet, is inligting oor die bewaringswaardigheid en bestuur van hierdie fragmente nodig. Hierdie studie stel dit ten doel om beter begrip te vorm van hoe fragmentasie die plantegroeipatrone en -dinamiek in die Kaapse laagland raak, en meer bepaald om vas te stel óf, en indien wel, in watter mate, hierdie fragmente tot streeksplantdiversiteit en -funksionaliteit bydra. Die ongewone studiebenadering konsentreer op funksionele kenmerke van plante, wat beter aanwyser van ekosisteemreaksie op wêreldwye verandering is as individuele spesies. Spesiemonsters is op vier skale by vier terreine van wisselende grootte ingesamel, wat insluit moederstrook en drie fragmente van elk van drie plantegroeisoorte in die Kaapse laagland, naamlik Atlantis-sandfynbos (ASF), Swartland-skalierenosterveld (SSR) en Langebaan-duinestrandveld (LDS). Kenmerke soos verspreiding, bestuiwing, voortplantingsmetode en lewensduur is gekies op grond van die tersaaklikheid daarvan vir spesies en plantfunksionele tipes (PFT’s) se reaksie op fragmentasie. Die studie bring verskillende uitwerkings op spesie-oorvloed en PFT’s aan die lig. Wat spesie-oorvloed betref, was die uitwerking van kleiner strookgrootte (“patch size”)duideliker te sien by ASF, waar fragmente kleiner as 600 ha beduidend minder spesies as die moederstrook bevat het. Hierdie uitwerking kon nie so duidelik by SSR en LDS waargeneem word nie weens verskeie strengelingsfaktore, veral die weidingsgeskiedenis van die terreine. Die SSR-fragment waarop inheemse herbivore gewei het, het beduidend meer spesies as die onbeweide terreine bevat. Voorts het die grootste LDS-fragment waarop vee gewei het heelwat meer spesies as die onbeweide moederstrook gehad, wat daarop dui dat weiding eerder as fragmentgrootte spesie-oorvloed beïnvloed, hoewel die kleinste fragmente van hierdie twee plantsoorte steeds aansienlik minder spesies as die groter fragmente bevat het. Spesie-omset en -aanvullendheid was hoog vir ál drie plantsoorte, wat aanwyser is van die mate van habitat-heterogeniteit en die groot bydrae wat betadiversiteit tot algehele gammadiversiteit lewer. Die uitwerking van kleiner strookgrootte was duideliker te bespeur op PFT-diversiteit as PFT-oorvloed – in dié verband het LDS, waar habitatfragmentasie mees onlangs plaasgevind het, die ligste van die drie plantsoorte afgekom. Dít dui op mate van funksionele oorbodigheid in die Kaapse laagland wat belangrik is vir ekosisteemweerstandigheid en -gehardheid. Die ASF-moederstrook en die grootste ASF-fragment het hoër PFT-diversiteit getoon as die medium- en kleinste fragmente; die moederstrook het in werklikheid oor hoër PFT-diversiteit as ál die fragmente saam beskik. Insgelyks het die kleinste SSR-fragment beduidend minder PFT-diversiteit en -oorvloed as die ander terreine getoon. Die beweide SSR-fragment was hoër in PFT-oorvloed én -diversiteit as die onbeweide moederstrook en die kleinste fragment, wat die rol van weiding in die instandhouding van renosterveldplantegroei beklemtoon. Die PFT’s wat nié op die verskillende terreine voorgekom het nie, was meestal tweehuisige en nietweehuisige spesies wat oor kort afstande versprei, en sommige spesies met hoogs gespesialiseerde bestuiwingstelsels. Dít dui daarop dat verspreiding en bestuiwing noodsaaklike funksionele kenmerke vir die voortbestaan van die bestudeerde gefragmenteerde ekosisteme is. Habitatfragmentasie raak die samestelling en ekologiese funksies van plantgemeenskappe in die Kaapse laagland. Dié gevolgtrekking word ook gerugsteun deur die bewese patrone van beduidende kenmerkkonvergensie (“trait convergence”) en divergensiesamekoms (“divergence assembly”). Hierdie plantgemeenskappe spruit uit verskeie fragmentasiefilters wat op verskillende ruimte-tydskale funksioneer, en wat spesies met geskikte reaksies kies. Ál drie plantsoorte is ontvanklik vir fragmentasie, hoewel in wisselende mate. Die fragmentasie-uitwerking is beïnvloed deur monsterinsameling- en tydskale, die soort versteuringsbedeling, en die kenmerkbemiddelde (“traitmediated”) verskille in spesiereaksie. Die rol van die omringende matriks op fragmentverbondenheid en geenvloei blyk van die allergrootste belang te wees, en dus word temperingsmaatreëls aanbeveel wat daarop gemik is om verbondenheid tussen stroke te verbeter, bedreigde taksa te moniteer, en verspreiding en bestuiwing aan te help. PhD Dissertation presented for the degree of Doctor of Philosophy (PhD) at Stellenbosch University
... These phalaenophilous flowers (Faegri and Pijl 1979, Silberbauer-Gottsberger and Gottsberger 1988) are usually small (although often in aggregate inflorescences), and often with minimal amounts of nectar. Most studies in the tropics have focused on sphingophily (Gottsberger and Gottsberger 1975, Haber and Frankie 1982, 1989, Nilsson et al. 1987) while the role of smaller moths and their interactions with tropical plants have been relatively little studied (but see Silberbauer-Gottsberger and Gottsberger 1988, Bawa 1990, Schulze et al. 2001, Goldblatt and Manning 2002). Here we review moth pollination in woody species of the Cerrado vegetation in Central Brazil, with more detailed case-history studies for two settling moth pollinated trees, Aspidosperma macrocarpon and Roupala montana, and for a hawkmoth pollinated tree, Qualea grandiflora. ...
Article
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We present a survey of moth pollination in woody species of the Cerrado of Central Brazil. Although with the exception of Roupala montana (which has simple polysepalous flowers arranged in dense cymes) all moth pollinated species in this community have tubular flowers, or a pseudo-tube formed from a single folded petal in Qualea grandiflora, settling moth flowers (tube less than 15 mm) vs. hawkmoth flowers (tube more than 50 mm) are markedly different in size. Moths visit some 20 woody Cerrado species, but they are probably effective pollinators of only 13 species or ca.14% of the woody taxa studied, and even in these latter species they are often very sparse visitors. Nevertheless, it is notable that moths are pollinators for 21% of the 38 most commonly distributed woody Cerrado species. Moreover, the reproductive efficacy of the studied moth pollinated species was similar to that of species pollinated by other kind of vectors.
... on the pattern in extant Crocoideae , the two - banded operculum is the ancestral state , and the one - banded operculum developed later via the two - banded state . If this view is accepted , the one - banded operculum in Hermodactylus tuberosus and Romulea spp . may be regarded as derived . This supports the view ( Moret et al . , 1992 , 1993 ; Goldblatt et al . , 2002 ) that Romulea is a particularly specialised genus based on floral biology , pollination and reproduction . ...
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The pollen morphology of numerous collections of taxa in the monocotyledonous families Amaryllidaceae, Ixioliriaceae and Iridaceae (order Asparagales) native to Turkey are presented in this study. Nineteen taxa from five genera of Amaryllidaceae, two taxa from Ixioliriaceae, and ten taxa from three genera of Iridaceae were examined with light and scanning electron microscopy. The pollen morphology is described in detail. In addition, pollen morphological data for Iris L., Crocus L. and Romulea Maratti taken from our previously published accounts are also included in the current report to provide an overall synthesis of the pollen characteristics of the three families in Turkey. The accumulated pollen data are described and discussed, and possible evolutionary trends for the pollen characters are considered.
... Plants with flowers accessible to a variety of visitors, flowers open both day and night, or multiple flower opening times (Koptur 1983), may get pollinated when extreme temperatures or heavy rains prevent visits to flowers during some parts of the day. A number of diurnal (day-open) versus nocturnal (night-open) comparisons have supported the nocturnal moth pollination syndrome, despite observations of plentiful daytime visitors (Young 2002, Reynolds et al. 2009); others have shown that pollination systems are more mixed than originally thought (Goldblatt and Manning 2002, Dar et al. 2006, Valdivia and Niemeyer 2006, Maruyama et al. 2010, Johnson et al. 2011. ...
... The pale perianth, attentuate tepals, evening anthesis and spicy floral fragrance are typical of moth-pollinated species (Goldblatt and Manning, 2002) and we infer that G. halophila is also adapted to moth pollination, although seed set is primarily through self-pollination. This combination of outcrossing and selfing is an evident adaptation to infrequent or unpredictable visits by pollinators, presumably associated with its arid habitat and flowering period in the middle of the dry season when few other plants are in bloom. ...
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The new species Gladiolus halophila Goldblatt & J.C.Manning from near Keetmanshoop in southern Namibia is described and illustrated. It is closely allied to G. longicollis and G. tristis from southwestern and eastern South Africa but is distinguished by its lilac flowers with shorter perianth tube, 35–40mm long. The flowers last just one day and are self-compatible. The species, which is restricted to saline seepages, is known from just two populations, one of which is due to be inundated by a planned dam, and it is therefore classified as Endangered. The action of the Namibian Government in commissioning a search for additional localities serves as a valuable example in similar instances.
... Butterfly pollination is evidently rare among southern African Iridaceae apart from the guild of species with large red flowers, mostly species of Gladiolus and Tritoniopsis, pollinated predominantly by Meneris tulbaghia (Satyridae) (Goldblatt & Manning 2002, a very different system to that reported here. Pollination by the painted lady, Cynthia cardui (Pieridae), has been observed in yellow-flowered Ixia acaulis Goldblatt & J.C.Manning and Nivenia parviflora Goldblatt & J.C.Manning, and this butterfly is the only recorded visitor to I. acaulis (Goldblatt & Manning 1993, 2011. ...
... If so, sugars would be determinant in attracting specific sets of pollinators and therefore could be potentially important in the establishment of different microbial communities in nectar. However, Baker and Baker's conclusions have been partly refuted by subsequent authors, due in part to the enormous variation between plant species that potentially should share characteristics, as occured in our study within the group of plants visited by birds (Barnes et al., 1995;Brown et al., 2009;Goldblatt et al., 1999), within the group of plants visited by non-beetle insects (Goldblatt & Manning, 2002;Goldblatt et al., 1998;Johnson, 2000;Johnson & Raguso, 2016;Msweli, 2018;Springer, 2019), and within the plants visited by beetles (Nicolson & Thornburg, 2007;Nicolson & Van Wyk, 1998;. Therefore, nectar sugars may not explain exclusively differences in microbial community composition among plants visited by different pollinator guilds. ...
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... Florece desde la primavera hasta el otoño. La polinización en su área de origen es realizada por Passeriformes Nectariniidae atraídos por su copioso néctar (Goldblatt & Manning, 2002Valente et al., 2012). Las semillas aladas tienen dispersión anemócora , y asimismo las plantas se expanden por propagación vegetativa, por medio de sus cormos; a menudo estos pueden ser ingeridos por cerdos salvajes en su área original o descartados de los cultivos y trasladados con los movimientos de tierra y desechos de jardines (Hosking et al., 2011;Lim, 2014). ...
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Resumen: En este trabajo se menciona por primera vez para la Argentina la presencia de Gladiolus dalenii (Iridaceae, Crocoideae) como especie naturalizada en la provincia de Misiones. Se incluye la descripción de la especie, sinonimia, iconografía, distribución geográfica, fenología, polinización, dispersión, nombres vernáculos, usos, material de referencia y comentarios sobre su naturalización. También se provee una clave para distinguir a G. dalenii de G. communis y G. tristis, las otras especies del género citadas con anterioridad como naturalizadas en el país. Además, se incluyen comentarios sobre híbridos de flores grandes escapados de cultivo en la provincia de Buenos Aires. Summary: In this work, the presence of naturalized Gladiolus dalenii (Iridaceae, Crocoideae) is reported for the first time for Argentina (Misiones province). The species description, synonyms, iconography, geographical distribution, phenology, pollination, dispersal, local names, uses, reference materials, and comments about its naturalization are provided. This study also presents a key to distinguish G. dalenii from G. communis and G. tristis, the other species of the genus already reported as naturalized in the country. Finally, findings of Gladiolus hybrids of large flowers escaped from cultivation in Buenos Aires province are commented.
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A particularly rich array of pollination systems is represented in the flora of southern Africa. Hopliine beetles, long-proboscid flies, satyrine butterflies, hawk moths, birds and rodents appear to assume greater importance as pollinators than they do in other temperate regions. These ‘alternative’ pollination systems may have developed because the bee-fauna of southern Africa is not particularly rich relative to the flora. Pollination by moths, for example, is relatively frequent in the eastern half of southern Africa where bee diversity is lowest. Pollination systems in southern Africa are relatively specialized and shifts between pollinators have been shown to be an important driving force in plant diversification and speciation. Changes in land-use, particularly afforestation and ploughing of grasslands, invasion of alien plants, overgrazing and urban developments have disrupted these mutualisms with mostly unknown consequences for ecosystem functioning. Future research will be directed at expanding our knowledge of pollination systems, with a strong focus on the conservation of mutualistic ecological interactions.
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Premise: There is little direct evidence linking floral development and pollination biology in plants. We characterize both aspects in plain and ornamented flowers of Trimezieae (Iridaceae) to investigate how changes in floral ontogeny may affect their interactions with pollinators through time. Methods: We examined floral ontogeny in 11 species and documented pollination biology in five species displaying a wide range of floral morphologies. We coded and reconstructed ancestral states of flower types over the tribal phylogeny to estimate the frequency of transition between different floral types. Results: All Trimezieae flowers are similar in early floral development, but ornamented flowers have additional ontogenetic steps compared with plain flowers, indicating heterochrony. Ornamented flowers have a hinge pollination mechanism (newly described here) and attract more pollinator guilds, while plain flowers offer less variety of resources for a shorter time. Although the ornamented condition is plesiomorphic in this clade, shifts to plain flowers have occurred frequently and abruptly during the past 5 million years, with some subsequent reversals. Conclusions: Heterochrony has resulted in labile morphological changes during flower evolution in Trimezieae. Counterintuitively, species with plain flowers, which are endemic to the campo rupestre, are derived within the tribe and show a higher specialization than the ornamented species, with the former being visited by pollen-collecting bees only.
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Gladiolus hamzaoglui (Iridaceae) is described and illustrated as a new species from Erzincan province in Eastern Anatolia, Turkey. It resembles G. halophilus by its secund inflorescence, obovoid fruit, and winged seed, and is related to G. anatolicus based on its leaf and flower features. Also it is compared to G. illyricus because of having some leaf, flower features, and winged seed characteristics. Its distribution, habitat and ecology, etymology, conservation status and diagnostic morphological, and taxonomic features with familiar species are discussed in this paper. Additionally, pollen and seed micromorphological characteristics of G. hamzaoglui, G. halophilus, and G. anatolicus are examined and compared using LM and SEM analyses. IUCN conservation status of G. hamzaoglui is suggested as Endangered (EN) category.
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Field observations, floral dissections, and pollen load analyses of insects captured on 35 species of Moraea (total 195 spp.), combined with past pollination studies on 16 more help identify five main floral types within this pan-African and Eurasian genus of Iridaceae. Most species are cross-pollinated by a narrow range of insects while a few are facultatively autogamous. Floral type determines whether a species is pollinated primarily by Coleoptera, Diptera, or Hymenoptera. Most common are flowers of the Iris-type, probably ancestral, that consist of three functionally separate bilabiate units (meranthia), each resembling one gullet flower. They are pollinated by a range of medium-sized to large bees of several families. Specialized adaptations related directly to the pollination system include reduction in the length of the tepal claws, enlargement of the outer tepal limbs, and acquistion of "beetle" marks combined with loss of nectar and scent, which shift the mode of pollination from the ancestral meranthium bee-pollinated type to painted bowl-beetle pollination using hopliine scarab beetles. Likewise, reduction in size of the style branches in conjunction with the loss of distinction between the inner and outer tepal whorls results in a cup- or bowl-like perianth, which combined with changes in floral odor favor more generalist systems including small bees, hopliines and flies, or flies exclusively. The shortening of the tepal claws together with the prominent display of pollen on an exaggerated column, leads to an active pollination system exploiting female bees of several families that harvest pollen to feed their offspring. © Publications Scientifiques du Muséum national d'Histoire naturelle.
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Gladiolus has been the important commercial cut-flower for summer crop in Romania for over 50 years. The floral commerce needs new varieties to boost yield and quality of flowers because the average wholesale price of flowers was no higher in recent years than it was 20 to 30 years ago. The improved of Gladiolus assortment with new cultivars and hybrids are one of the main objectives of researches of the Fruit research Station, Floral department. The aim of this paper was to present new three cultivars ('Medina', 'Coral Pasion' and 'Incandescent') and three hybrids (H 208/3, H 303/1 and H 447/8) created by artificial crossing, followed by clonal selection. The new varieties were analyzed concerning the main morph-decorative characteristics such as color of flower, vigor of plant, length of stem, number of florets per spike, floral diameter, the behavior of flower in vase life and multiplication capacity.
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Floral morphology and observations on insect and avian visitors to species of the southern African and largely Western Cape genus Tritoniopsis indicate that short-tubed pink flowers, ancestral in the genus, are pollinated by anthophorine bees forging for nectar. Multiple shifts to more specialized pollination systems have occurred in the genus during its evolution. Four species with elongate floral tubes and a pink to red bilabiate perianth are pollinated either by sunbirds (Nectarinia) alone or by sunbirds and the satyrid butterfly Aeropetes tulbaghia. Another red-flowered species with an actinomorphic flower is inferred to be pollinated only by Aeropetes, while two species with pale pink flowers with red markings are pollinated by long-proboscid flies in the genus Prosoeca (Nemestrinidae). Tritoniopsis parviflora is unique in the African Iridaceae in producing floral oils as a reward to the short-tongued bee Rediviva gigas (Melittidae), as well as conventional sugar nectar. Tritoniopsis nervosa has white, sweetly scented, long-tubed flowers and is assumed to be pollinated by night-flying moths. Although relationships within Tritoniopsis are poorly understood, it is clear that at least five shifts in pollination strategy have occurred in this genus of just 24 species. Studies also show that bimodal pollination systems using two different pollinator groups occur in several species, using sunbirds and Aeropetes, anthophorine bees and nemestrinid flies, or oil-collecting Rediviva and nectarivorous bees. Such bimodal systems are probably important for the successful reproduction of these plants.
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Endemic to the southern Roggeveld Plateau in Northern Cape, South Africa, Romulea syringodeoflora (Iridaceae: Crocoideae) is an acaulescent geophyte with pink, salver-shaped, odorless flowers with a narrow, elongate perianth tube 18–25 mm long. The stamens are exserted from the tube and have brown anthers prominently displayed on filaments ± 4.5 mm long. The perianth tube contains 0.7–1.2 μl of nectar in the lower half with a mean concentration of 23.5% sucrose equivalents. The flowers are visited systematically by an unnamed species of Prosoeca, a long-proboscid fly in the family Nemestrinidae, and occasionally by the butterfly Cynthia cardui (Nymphalidae) and the anthophorine bee Amegilla spilostoma (Apidae). The flies have a proboscis 10.5–11.5 mm long, which when inserted into the floral tube reaches the nectar held within the lower half of the tube. The frons and the proximal part of the head of the Prosoeca sp. contact the anthers during feeding, and the flies accumulate visible quantities of brown pollen during foraging bouts. Observations showed that these insects also contacted the stigmatic surfaces of style branches during this activity. Amegilla bees, which occasionally visit Romulea flowers, have a tongue ± 7 mm long and fail to reach the nectar when they insert their proboscis into the tube. Because of their small size they do not brush against the anthers or style branches when they attempt to forage. These observations confirm our prediction of long-proboscid fly pollination in this species of Romulea, based on the floral morphology of the species, and expands the range of plant species known to have flowers adapted for pollination by this group of insects.
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Numerous insect species feed on the pollen, nectar and other plant exudates that are associated with flowers. As a result of this feeding activity, pollen becomes attached to the insects. Analysis of this pollen can reveal what insects eat, their dispersal patterns in and around cropping systems and their role in pollination. However, finding pollen on and/or in an insect depends on the technique used to recover pollen from the insect. Six different techniques are described in detail that have been used to recover pollen from a variety of insects including pests such as boll weevils, Mexican corn rootworms and corn earworm moths. These techniques can be use to recover pollen from internal insect tissues (gut, alimentary canal, crop, etc.), external tissues (proboscis, legs, eyes, etc.) or both. By using the most appropriate technique, better pollen recovery can be made and thus better data obtained.
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Field observations, floral dissections, floral nectar, and pollen load analyses of captured insects of 53 species of Babiana Ker Gawl. show that flowers of this geophytic genus of some 90 species of Iridaceae subfamily Crocoideae, predominantly of the southern African winter-rainfall zone, are cross pollinated by a wide range of animals. These include passerine birds and insects of four different orders, Hymenoptera (mainly Apidae), Diptera (mainly Nemestrinidae), Coleoptera (Scarabaeidae), and Lepidoptera (mainly Noctuidae). Apid pollination involves two discrete systems—passive pollination by anthophorines and native Apis mellifera foraging for nectar and active pollen gathering by A. mellifera and other Apoidea foraging for pollen. From what is known about relationships within Babiana and Crocoideae, it seems likely that passive pollination by anthophorines and honeybees, with nectar secreted in zygomorphic, bilabiate flowers as a reward, is the ancestral condition; it is also the most common, demonstrated for 18 and inferred for 35 more species from all three taxonomic sections of the genus. Active pollination by honeybees and female Apoidea foraging for pollen was demonstrated in one species and is inferred for four more, all of which have radially symmetric flowers and prominent anthers. Pollination by long-proboscid nemestrinids, mostly species of Prosoeca, is recorded for 13 species and inferred for five more, while moth pollination is recorded for one species and inferred for another two. Pollination exclusively by hopliine scarab beetles, known for six species, is associated with development of radial symmetry of the flower. Passerine bird pollination, associated with the classic syndrome of a wide floral tube, red floral pigmentation, and rigid, well-exserted stamens, occurs in two species, and is inferred for one more. Species with a bimodal system in which bees and beetles both visit and accomplish pollen transfer is known for three species. Comparing pollination systems with what is known about species relationships in Babiana, we infer that long-proboscid fly pollination evolved at least four times and moth pollination three times. Active pollination by pollen-collecting bees and hopliine beetle pollination also probably evolved three times each and bird pollination twice. Pollination systems are labile, and we postulate that there has been a minimum of 14 shifts in pollination system, approximately one shift for every six species. Lastly, Babiana species show the same correlation of morphology and floral presentation with particular sets of pollinators, described for several other genera of Iridaceae, e.g., Gladiolus L., Hesperantha Ker Gawl., and Lapeirousia Pourr., as well as Geraniaceae and Orchidaceae. This increases our confidence in predicting pollinators on the basis of floral presentation in other species and genera in which pollinators have not been established.
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Gladiolus, a perennial geophyte, belongs to the family Iridaceae. Gladiolus species were recognized over 2,000 years ago in the field of Asian Minor. The European species were cultivated at least 500 years ago and first reported to be found in New Forest, UK in 1855, was evolved within short time to occupy top ranks of international flower trade. About 255 species of the genus were reported, out of which more than 114 are native to South Africa. The origin, distribution, and taxonomy of this genus are detailed in this chapter. Polyploidy and significant variation were reported for the chromosome number in Gladiolus but in many species base number was x = 15. Extent of genetic erosion, endangered species (like Gladiolus alatus var. algoensis), and modes of conservation including cryopreservation have been discussed. A detailed account of genetic improvement right from natural hybridization among the species G. communis, G. careneus (G. bladus), and G. cardinalis before 1880 to advanced techniques using molecular markers is given. Mention about change in breeding objectives over a period of time, utilization of wild species for crop improvement, advances in genetic transformation through non-conventional methods is also made. The contribution of different species in the development of modern-day cultivars and the process of evolution are also discussed. Breeding for fragrance, a trait lost in the course of evolution and most desired today is detailed. Economic importance of the genus and further scope for domestication and commercialization are mentioned.
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Understanding the evolution of floral morphology requires information about the identity of pollinators as well as the specific mechanisms of pollen transfer. Based on preliminary field observations and floral structure, we hypothesized that pollination mechanisms involving the transfer of pollen on butterfly wings occur in several lineages of South African Amaryllidaceae. Here we report findings from a detailed study of butterfly-wing pollination in two subspecies of Scadoxus multiflorus and review the prevalence of this pollination mechanism among other Amaryllidaceae in southern Africa. We established that S. multiflorus subsp. katherinae is genetically self-incompatible and thus entirely reliant on pollinators for seed production. We determined that this subspecies is pollinated almost exclusively by large swallowtail butterflies, principally males of the mocker swallowtail Papilio dardanus cenea. Flowers of S. multiflorus subsp. multiflorus are pollinated by pierid and swallowtail butterflies. Pollen is deposited on the ventral surface of the wings of butterflies as they flutter over the strongly exserted stamens. We predict that butterfly-wing pollination occurs in at least nine species of South African Amaryllidaceae, which may reflect several independent origins of this mechanism. The flowers of these species are red or orange with strong herkogamy and are either bowl-brush or open-brush in shape. We provide maps of the distribution of pollen on the ventral surface of the wings of pollinators for four of these species. All four appear to be pollinated via the ventral surface of large butterfly wings, with the floral structure facilitating the process. These findings illustrate the importance of investigating pollen transfer mechanisms in order to understand patterns of floral diversification and floral convergence.
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Field observations, floral dissections of a representative range of Hesperantha species, and pollen load analyses of insects captured on many of them indicate that flowers of this African genus are cross pollinated by a relatively broad range of insects. The pollination ecology of Hesperantha can be divided into four overlapping systems that exploit insects of four orders (Coleoptera, Diptera, Hymenoptera, and Lepidoptera). Species of the H. falcata type have erect or nodding, salver-shaped, strongly fragrant, white flowers that open in the mid to late afternoon and evening and are pollinated by long-tongued apid bees and/or noctuid moths. Species of the H. pauciflora type have a virtually identical floral morphology, but the perianth is yellow or pink to mauve or blue and the flowers are usually unscented and are open during the day, closing between midday and late afternoon, ca. 16:30 H. Flowers of this type are also pollinated by apid bees, but in the southern African winter-rainfall zone other effective pollinators include nemestrinid flies (Prosoeca) with relatively short probosces and hopliine scarab beetles. In H. latifolia type flowers the perianth is pink to magenta or red (rarely pale yellow), odorless, opens during the day but has an elongate perianth tube exceeding 18 mm in length. These flowers are pollinated mainly by long-proboscid flies in the genera Prosoeca and Stenobasipteron (Nemestrinidae) or Philoliche (Tabanidae), but the red flowers of H. coccinea are pollinated by a guild of large butterflies including Papilio and the satyrid Aeropetes. Lastly, H. vaginata has odorless and nectarless, short-tubed yellow flowers, usually with contrasting dark markings, that open only during the day and are pollinated exclusively by the hopliine scarab beetle, Clania glenlyonensis. The taxonomic distribution of plant species with these pollination systems makes it clear that shifts in pollination systems have occurred repeatedly across Hesperantha, although floral morphology and nectar biochemistry are relatively conservative. Whether flowers are nocturnal, crepuscular, or diurnal, only four vari- ables affect the floral ecology: length of the perianth tube, presence or absence of floral fragrance, timing of anthesis, and the closely associated trait of perianth color. Thus, species with pink, magenta, red, or yellow flowers close at night and are rarely fragrant, whereas those with white or pale yellow flowers are nearly always fragrant and either open late in the day or only at sunset and remain open for most of the night. Species show considerable variation in nectar volume and sugar concentration, closely correlated with pollination system, while two long-tubed species with floral characters typical of long-proboscid fly pollination produce no nectar and are inferred to be Batesian or guild mimics
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ABSTRACT Gladiolus is grown all over the world for cut flower production for floriculture trade. Extensive research has already been done on gladiolus to generate basic knowledge on multidisciplinary aspects. Efforts in germplasm collections, characterisation, cytology, tissue culture, disease management, classical improvement and induced mutation are worth mentioning. Despite significant technological advances, we are still repeating some of our experiments as routine activities. Selective breeding is now most essential to develop varieties as per requirement of the trade. This will be possible in two ways-utilising all available knowledge as guidelines and identification and wise selection of parents having desirable genes prior to cross-breeding.
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Flowers of Dipcadi brevifolium (Hyacinthaceae) exhibit the characteristics associated with phalaenophily, or pollination by settling moths, notably a dull-coloured, shortly tubular perianth with included anthers, and nocturnal scent. Flowers are self-incompatible and produce an unusual, sour/acrid floral scent dominated by isobutyric acid, 2-methylbutyric acid and jasmine. The moth Syngrapha circumflexa (Noctuidae) was recorded as a pollinator, representing the first pollination record for the species and for the genus.
Chapter
Insect pollinators are a key component in providing vital ecosystem services to crops and wild plants. Honey bees are regarded as beneficial insects for their crucial role in pollination besides their valuable products like honey, wax, pollen, venom, royal jelly and propolis. Modern commercial crop production is increasingly dependent on managed pollinators (e.g. the introduction of honey bee; Apis mellifera and Apis cerana colonies into orchards or fields to improve crop production). Owing to various biotic and abiotic stresses in honey bees, relying only on them for commercial pollination may lead to insufficient pollination in different crops. The bumble bees and stingless bees are effective available pollinators for greenhouse crops. Managed non-Apis bees (Osmia, Nomia, Megachile) are effective pollinators of specific crops and can be used commercially in crop production. Other important pollinators include wasp, syrphid flies, butterfly and some beetles. The crop pollination by insects estimated approximate $361 billion of crop production worldwide. To ensure higher crop production, it is mandatory to conserve the native pollinators, and manage wild bees and other non-hymenopteran pollinators for wider ecosystem stability and food security. Potential of various groups of insects (the honey bees, stingless bees, bumble bees; solitary bees: blue-banded bees, leafcutter bees, mason bees, carpenter bees, alkali bees; syrphid flies, butterflies, wasps and beetles) for crop pollination is reviewed in this chapter.
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Plant-pollinator interactions are key components of the dynamics of most terrestrial ecosystems. Since species interactions are considered to play a central role in many speciation events, studying the evolutionary history of traits closely linked to this kind of interaction contributes to improve our knowledge of the mechanisms involved. Insects are the largest group of animals visiting flowers to collect mostly pollen and/or nectar, but some insects seek other resources. Relationships between oil-secreting flowers and specialized oil-collecting bees constitute an example of a close and uncommon interaction. Flowers offering oil as a resource are found in only 11 families distributed across the angiosperms among unrelated orders. In most of these families floral oil-producing structures (elaiophores) evolved only once, except in Orchidaceae and Iridaceae where oil rewards evolved multiple times. Furthermore, even if our phylogenetic knowledge is too incomplete to infer how many times and how elaiophores have evolved within the Iridaceae, the number and the geographical distribution of oil-flower species suggest that transitions to floral oil-producing structures may well have played a key role in the diversification of the Iridoideae subfamily on the American continent.The goal of this study was to improve our knowledge of the evolutionary history of this uncommon pollination system and to test whether the evolution of elaiophores is a causal factor of diversification within the Iridaceae. Species of the American genera of Iridoideae were widely sampled in the field to produce robust phylogenetic frameworks at two different taxonomic levels. This work aimed at better understanding the evolution of the pollination strategies related to floral oil-secretion not only in the general context of the subfamily but also at a lower taxonomic level. Sisyrinchium, the largest genus in the New World Iridoideae, including species with oil-producing flowers and species with only pollen flowers, was selected for the second part of this study. Phylogenetic analyses were combined with micro-morphological and functional characterizations of the floral structures potentially involved in plant-pollinator interactions within the genus.The results showed that elaiophores evolved several times at both taxonomic levels and that this homoplastic character has played a key role in the diversification of the family on the American continent. For future prospects, thorough studies of the reproductive and pollination biology are required to elucidate how these interactions impact the dynamics of the ecosystems in which they occur.
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To select suitable genetic resources for scent breeding, we qualitatively and quantitatively analyzed floral scent emitted from 9 wild Gladiolus species. Dynamic headspace collection was performed and scent compounds emitted from the wild species were analyzed using gas chromatography-mass spectrometry, resulting in detection of twenty scent compounds. The analyzed species were divided into 4 groups; Linalool/Benzenoid group, Nerol group, Ionone group or Ocimene/Caryophyllene group. Based on the kind and amount of scent compounds we selected G. orchidiflorus, G. recurvus, G. tristis and G. watermeyeri as potential genetic resources for fragrance. Temporal changes in emissions were investigated in 3 promising species that were selected. G. orchidiflorus emitted the maximum amount of scent compounds between 10:00 and 14:00 while the maximum output of G. recurvus and G. tristis was between 18:00 and 22:00. This differential release of scent compounds during the day is an important character to select for, in addition to the quality and quantity of scent compounds, in breeding program for Gladiolus.
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Gladiolus rhodanthus is a new species known from a single population on the summit of the Stettynsberg near Villiersdorp in Western Cape, South Africa. The species most closely resembles G. hirsutus and G. caryophyllaceus but differs from both in flower shape and markings and in its ecology and reproductive biology. It forms part of a guild of long-tubed, pink-flowered species including Erica praecox, Pelargonium radiatum and Watsonia paucifolia which are pollinated by an undescribed long-proboscid fly, Moegistorhynchus sp. nov. (Diptera: Nemestrinidae). Gladiolus sekukuniensis is a new species known from three populations south of the Strydpoortberge in Northern Province. It closely resembles G. permeabilis subsp. edulis in vegetative features and in flower form, but differs from it in flower colour and in the elongate perianth tube. These floral features are apparently adaptations to pollination by long-proboscid flies.
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