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Pogoniopsis nidus-avis. A. Habit; B. Flower; C. Fruits (note the persistent perianth parts); D. Scanning Electron Microscopy (SEM) image of a sclerified seed. Note the remnant of the funiculus (arrow); E. Longitudinal cut of a seed stained with toluidine blue. Note the funiculus and the placenta; F. Longitudinal section of an ovule stained with toluidine blue showing the cells with large nuclei and densely stained cytoplasm. Note the granules, which are related to embryo nutrition (arrows).
Source publication
Vanilloideae as currently circumscribed comprises nine genera and two tribes: Vanilleae and Pogonieae. The pantropical genus Vanilla has been frequently assumed to be natural on the basis of its climbing habit and lateral inflorescences. However, the inclusion of the rare Dictyophyllaria dietschiana in phylogenetic analyses makes the genus Vanilla...
Contexts in source publication
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... ). However, a phylogenetic analyses show that inclusion of Pogoniopsis turns the tribe paraphyletic ( Fig. 1; Pansarin et al. 2012). All analyses reveal that Pogoniopsis is closely related to members of Epidendroideae ( Fig. 1; Pansarin et al. 2012). Pogoniopsis have a sympodial habit with reduced leaves. The inflorescence is a terminal raceme (Fig. 3A). The flowers are whitish and the perianth is persistent (Figs. 3A-B). The labellum is 3-lobed and presents clusters of yellow hairs on its mid portion. The lateral lobes are falcate and entire, while the apical lobe is spatulate and fringed. The pollen of Pogoniopsis nidus-avis is free and the anther is versatile. Furthermore, the ...
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... turns the tribe paraphyletic ( Fig. 1; Pansarin et al. 2012). All analyses reveal that Pogoniopsis is closely related to members of Epidendroideae ( Fig. 1; Pansarin et al. 2012). Pogoniopsis have a sympodial habit with reduced leaves. The inflorescence is a terminal raceme (Fig. 3A). The flowers are whitish and the perianth is persistent (Figs. 3A-B). The labellum is 3-lobed and presents clusters of yellow hairs on its mid portion. The lateral lobes are falcate and entire, while the apical lobe is spatulate and fringed. The pollen of Pogoniopsis nidus-avis is free and the anther is versatile. Furthermore, the flowers are characterized by the absence of the abscission zone between ...
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... The pollen of Pogoniopsis nidus-avis is free and the anther is versatile. Furthermore, the flowers are characterized by the absence of the abscission zone between perianth and ovary (a characteristic common to members of Vanilloideae; Pansarin & Barros 2008, 2012, rewardless, flowers opening in succession, with fleshy and indehiscent fruits (Fig. 3C), and ovoid seeds with a crustose seed coat (Figs. ...
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... the anther is versatile. Furthermore, the flowers are characterized by the absence of the abscission zone between perianth and ovary (a characteristic common to members of Vanilloideae; Pansarin & Barros 2008, 2012, rewardless, flowers opening in succession, with fleshy and indehiscent fruits (Fig. 3C), and ovoid seeds with a crustose seed coat (Figs. ...
Citations
... Dressler 1968Dressler , 1981. Furthermore, it is widely known that members of the euglossinophilous clade are pollinated via a combination of perfume production (responsible for attracting euglossine males to flowers) and nectar searching Pansarin 2016Pansarin , 2019. ...
... Melipona bees have also been recorded as floral visitors of V. pompona Schiede (Lubinsky et al. 2006); however, except for the bird-pollinated V. palmarum, members of this Neotropical thick-leafed clade are adapted to pollination by long-tongued (i.e. Euglossini) bees (Pansarin 2016(Pansarin , 2019(Pansarin , 2022Pansarin & Ferreira 2022). Male euglossine bees show a typical behaviour towards fragrance compound collection on flowers of members of the euglossinophilous Vanilla clade (Lubinsky et al. 2006;. ...
... The preference for collecting fragrance compounds had already been described in previously published studies (e.g. Pansarin 2016Pansarin , 2019, and this behaviour is likely due to the fact that young, short-lived males seem to be more interested in sex than food. In fact, the lifespan of a male euglossine is less than half that of a female. ...
Commonly attributed to orchids, the pollen movement in Vanilla has been associated with food deception and specific plant–pollinator relationships.
This study investigated the role of flower rewards and pollinator specificity in the pollen transfer of a widely distributed member to the euglossinophilous Vanilla clade, V. pompona Schiede using data collected from Brazilian populations. These included investigations on morphology, light microscopy and histochemistry, and analysis of flowers scent using GC–MS. The pollinators and the mechanisms of pollination were recorded through focal observations.
The yellow flowers of V. pompona are fragrant and offer nectar as reward. The major volatile compound of the V. pompona scent, carvone oxide, shows convergent evolution in Eulaema ‐pollinated Angiosperms. The pollination system of V. pompona is not species‐specific, but its flowers are strongly adapted to pollination by large Eulaema males. Pollination mechanism is based in a combination of perfume collection and nectar seeking.
The dogma of a species‐specific pollination system based on food deception in Vanilla has been broken with the increase in studies on this Pantropical orchid genus. Here, least three bee species and dual reward‐offering are involved in pollen transfer in V. pompona . Visitation frequency of bees collecting perfumes, used in courtship by male euglossines, is higher than in searching for food, as short‐lived young euglossine males seem to be more interested in sex than food. A pollination system based on offering both nectar and perfumes as resources is described for the first time in orchids.
... However, its local position with respect to tribe Triphoreae and multiple other clades in Epidendroideae was poorly supported in the phylogenetic study of Cameron and van den Berg (2017). In the meantime, other publications have continued to consider Pogoniopsis as a member of subfamily Vanilloideae based on various data types, including nuclear markers (Pansarin et al., 2008(Pansarin et al., , 2012 and fruit morphology (Pansarin, 2016(Pansarin, , 2021. This continuing uncertainty points to a need for further study of its phylogenetic relationships. ...
Premise:
Pogoniopsis likely represents an independent photosynthesis loss in orchids. We use phylogenomic data to better identify the phylogenetic placement of this fully mycoheterotrophic taxon, and investigate its molecular evolution.
Methods:
We performed likelihood analysis of plastid and mitochondrial phylogenomic data to localize the position of Pogoniopsis schenckii in orchid phylogeny, and investigated the evolution of its plastid genome.
Results:
All analyses place Pogoniopsis in subfamily Epidendroideae, with strongest support from mitochondrial data, which also place it near tribe Sobralieae with moderately strong support. Extreme rate elevation in Pogoniopsis plastid genes broadly depresses branch support; in contrast, mitochondrial genes are only mildly rate-elevated and display very modest and localized reductions in bootstrap support. Despite considerable genome reduction, including loss of photosynthesis genes and multiple translation apparatus genes, gene order in Pogoniopsis plastomes is identical to related autotrophs, apart from moderately shifted inverted repeat (IR) boundaries. All cis-spliced introns have been lost in retained genes. Two plastid genes (accD, rpl2) show significant strengthening of purifying selection. A retained plastid tRNA gene (trnE-UUC) of Pogoniopsis lacks an anticodon; we predict it no longer functions in translation but retains a secondary role in heme biosynthesis.
Conclusions:
Slowly evolving mitochondrial genes clarify the placement of Pogoniopsis in orchid phylogeny, a strong contrast with analysis of rate-elevated plastome data. We documented the effects of the novel loss of photosynthesis: for example, despite massive gene loss, its plastome is fully colinear with other orchids, and it displays only moderate shifts in selective pressure in retained genes. This article is protected by copyright. All rights reserved.
... are pollinated by nectar deception (e.g. Pansarin, 2016;Chaipanich et al., 2020); however, the new data presented here show that the assumptions about the absence of reward-based production in Vanilla flowers is probably related to the lack of literature information, as previous conclusive studies are limited to only a few species (e.g. . However, no evident nectar secretion has been recorded here for V. edwallii, V. planifolia, V. paulista or V. ribeiroi, resources in angiosperms is that the production of floral rewards can be energetically expensive, whereas in deceptive species the energy expenditure associated with reward production can be more usefully allocated to other functions (Ackerman, 1986). ...
In many flowering plants the attraction of pollinators is related to some kind of deception. Pollination by food-deception occurs in several angiosperm groups and is particularly widespread in orchids. Despite the apparent evolutionary success of pollination by food-deception, food-deceptive orchids show a low level of fruit set. Although studies are scarce, the pollination of Vanilla has been usually associated with nectar-deception. In Vanilla spp. (Vanilla bahiana, V. bicolor, V. chamissonis, V. edwallii, V. hartii, V. phaeantha, V. paulista, V. planifolia, V. ribeiroi and V. pompona), understanding the factors associated with pollinators is essential, since in vanilla production a cumbersome process of supplementary manual pollination is necessary to increase fruit set, which is frequently low under natural conditions. The production of floral rewards was investigated here in ten Neotropical Vanilla spp. based on morpho-anatomy and histochemical analyses of flowers. Six species (Vanilla bahiana, Vanilla bicolor, Vanilla chamissonis, Vanilla hartii, Vanilla phaeantha and Vanilla pompona) offer nectar as a reward. In Vanilla ribeiroi, the long trichomes of the labellum base are rich in starch grains and proteins, characteristic of food-hairs. The only secretory structures of Vanilla edwallii are osmophores on the inner surface of the labellum that are related to the attraction of oil-collecting bees as pollinators. Vanilla spp. possess sepaline and labellar osmophores. Inside the labellum the osmophores are arranged along longitudinal lines and act as resource guides. Although it is widely known that Vanilla flowers attract pollinators by nectar deception, the present data reveal that there may be a lack of knowledge regarding pollination in this group since the offer of nectar appears to be a common condition, at least for the euglossine-pollinated Neotropical clade. The remaining Neotropical groups exhibit other pollination strategies, such as the production of food-hairs and fragrances that attract oil-collecting bees to the flowers. The study of Vanilla pollination is extremely important because the need for manual pollination, added to the ripening and curing time, causes vanilla to be one of the most expensive spices in the world. According to the data presented here, the pollination systems of vanilla are much more diverse than classical “food deception”.
... Perhaps flower micro-morphology was shown to be important in pollinator preference (Whitney et al. 2009;Whitney et al. 2011) and the presence of certain micromorphological characteristics on the flower (e.g. the presence of conical cells) increase pollination success (Glover and Martin 1998) and allow flower discrimination (Kevan and Lane 1985); the main focus of most of the studies involving floral trichomes has been the morphological description. The positive effect of floral trichomes on pollination success can be indirectly observed since they are important in trapping and retaining pollinators within the flowers (Oelschlägel et al. 2009), in capturing pollen to be then transferred to the stigma (Arathi and Kelly 2004), or because pollinators use them as floral guides (Pansarin 2016). However, to the best of our knowledge, there is only one study testing directly the impact of trichomes on pollination success; that study demonstrated that the presence of trapping trichomes in Ceropegia L. (Apocynaceae) did not increase pollinia removal, but probably pollinia deposition (Coombs et al. 2011). ...
Floral innovations are key for pollinator specialization and play a significant role in plant diversification. Orchidaceae present many examples of floral innovations that allow its high degrees of pollinator specialization and promoted speciation. The rich neotropical genus Telipogon evolved an uncinate (=hook-like) viscidium on the pollinarium and setae-bearing flowers, which are uncommon in Orchidaceae; however, the importance of them on pollination success and whether they are floral innovations or exaptations in Telipogon have not been investigated. Here we investigate the morphology of the viscidium and floral setae within the Telipogon alliance (including the genera Hofmeisterella, Trichoceros and Telipogon), test their significance in pollination, and their occurrence and evolution across the Oncidiinae. We used Telipogon peruvianus as a model species to test whether uncinate viscidium and floral setae increased pollination success compared with a cochleariform (=spoon-like) viscidium and lack of floral setae condition. We show that the uncinate viscidium is a synapomorphy for Telipogon; setae-bearing flowers are not universally found among all species of Telipogon and evolved once in the Telipogon alliance. Furthermore, Telipogon peruvianus flowers with an uncinate viscidium have achieved higher pollinia export than those with cochleariform viscidium (ancestral condition), whereas flowers with setae have both higher success in pollinia removal, although not significant, and pollinia deposition than those lacking of setae (ancestral condition). We demonstrate that uncinate viscidia and floral setae in Telipogon are a key innovation and exaptation, respectively, that enhance pollination success and they might act as drivers of diversification and pollinator specialization in this genus.
... The Vanilla genus is known for its fragrant flowers, with no species lacking a fragrance currently known. Fragrance seems to play an important part in attracting pollinators for many Vanilla species (Soto-Arenas and Cameron, 2003;Lubinsky et al., 2006Householder et al., 2010Soto-Arenas and Dressler, 2010;Pansarin, 2016). For example, the unusual high fruit set produced by V. chamissonis Klobschis was attributed to the strong floral fragrance (Gigant et al., 2011). ...
The orchid genus Vanilla has a pantropical distribution. It includes notable species, particularly Vanilla planifolia and V. pompona from the tropical Americas, and the first commercial hybrid V. tahitensis. Both species are used in various industries, including food, pharmaceuticals, cosmetics, tobacco, insect repellent, and traditional crafts. Less known is V. siamensis from Thailand. Here we investigate the flower morphology, fruit set, and natural pollinator of V. siamensis. Flower morphology and pollination experiments indicate that the species is pollinator-limited, thus undergoing pollination via deception. During observations of visiting insects, eight insect groups were collected (Blattodea, Coleoptera, Diptera, Hemiptera, Hymenop-tera, Lepidoptera, Mantodea, and Orthoptera), representing twenty-eight insect morpho-species. The most frequent visiting group was the Hymenoptera, which accounted for the largest value of frequency of occurrence with 80% of the total visitations. The main visitor, Thrinchostoma sp. 2 is most likely the pollinator as observed at Khao Soi Dao Wildlife Sanctuary in the eastern region of Thailand. This species was observed entering a flower carrying Vanilla-like pollen before exiting with the pollen having been removed. It is therefore suggested that pollination of V. siamensis is by the Thrinchostoma bees, under natural conditions; however, visitations are infrequent, resulting in pollinator-limitation when compared to hand pollination experiments.
Orchids are a diverse group of plants, also manifested in their great diversity of flowers. Despite this, orchids are pollinated either through autogamy or allogamy (geitonogamy and xenogamy). Although there are some autogamous orchids, the majority are allogamous, mainly pollinated by xenogamy since they present physical or genetic barriers that prevent self-pollination. In addition, orchids are known for their capacity for interspecific pollination, which could influence fruits (metaxenia) and seeds (xenia) production. Its capacity for hybridization represents an opportunity to produce organisms tolerant to biotic or abiotic stress, in addition to exhibiting new shapes, colors and fragrances; this would be important in horticulture, where the proper selection of parents provides those advantages to the descendant hybrids. This review addresses the characteristics of each type of reproduction systems in orchids, as well as their advantages and disadvantages. At the same time, the study of the induction effect of metaxenia and xenia in this family is proposed. Finally, the production of orchid hybrids is contextualized and the opportunities of this approach in the near future.
Premise:
Although vanilla is one of the best-known spices, there is only a limited understanding of its biology and genetics within Mexico, where its cultivation originated and where phenotypic variability is high. This study aims to augment our understanding of vanilla's genetic resources by assessing species delimitation and genetic, geographic, and climatic variability within Mexican cultivated vanilla.
Methods:
Using nuclear and plastid DNA sequence data from 58 Mexican samples collected from three regions and 133 ex situ accessions, we assessed species monophyly using phylogenetic analyses and genetic distances. Intraspecific genetic variation was summarized through the identification of haplotypes. Within the primarily cultivated species, Vanilla planifolia, haplotype relationships were further verified using plastome and rRNA gene sequences. Climatic niche and haplotype composition were assessed across the landscape.
Results:
Three species (Vanilla planifolia, V. pompona, and V. insignis) and 13 haplotypes were identified among Mexican vanilla. Within V. planifolia haplotypes, hard phylogenetic incongruences between plastid and nuclear sequences suggest past hybridization events. Eight haplotypes consisted exclusively of Mexican samples. The dominant V. planifolia haplotype occurred throughout all three regions as well as outside of its country of origin. Haplotype richness was found to be highest in regions around Papantla and Chinantla.
Conclusions:
Long histories of regional cultivation support the consideration of endemic haplotypes as landraces shaped by adaptation to local conditions and/or hybridization. Results may aid further genomic investigations of vanilla's genetic resources and ultimately support the preservation of genetic diversity within the economically important crop.
Natural pollination of species belonging to the pantropical orchid genus Vanilla remains poorly understood. Based on sporadic records, euglossine bees have been observed visiting flowers of Neotropical Vanilla species. Our research aimed at better understanding the pollinator attraction mechanism of the Neotropical species Vanilla pompona, a crop wild relative with valuable traits for vanilla crop improvement programs. Using video footage, we identified floral visitors and examined their behavior. The flowers of V. pompona attracted Eulaema cingulata males, which distinctively displayed two behaviors: floral scent collection and nectar search; with the latter leading to pollen removal. Morphological measurements of floral and visitor traits showed that other Eulaema species may also act as potential pollinators. Additionally, we recorded natural fruit set in three populations and over a period of two years, tested for nectar presence and analyzed floral fragrances through gas chromatography - mass spectrometry. We observed a low natural fruit set (2.42%) and did not detect nectar. Twenty floral volatile compounds were identified, with the dominant compound trans-carvone oxide previously found to attract Eulaema cingulata males. We hypothesize a dual attraction of Eulaema cingulata males to V. pompona flowers, based on floral fragrance reward as the primary long-distance attraction, and food deception for successful pollen removal. Further research confirming this hypothesis is recommended to develop appropriate conservation policies for Vanilla crop wild relatives, which are the primary reserves of this crop’s genetic variation.
