Pre-pollination isolation by pollinator specificity: settling moth versus hawkmoth pollination in two sympatric Habenaria species (Orchidaceae)

BMC Plant Biology, Journal Year: 2025, Volume and Issue: 25(1)

Published: April 3, 2025

Habenaria species typically produce green or white flowers, bear nectar spurs, emit crepuscular-nocturnal scents, and are usually pollinated by crepuscular/nocturnal moths. However, the roles of floral traits in pollinator differentiation contributing to reproductive success sympatric require further definition. In this study, we investigated flowering phenology, traits, behavior, two co-occurring co-blooming (H. ciliolaris H. schindleri) southeastern China. We also conducted intraspecific interspecific hand pollinations determine their respective breeding systems extent post-pollination isolation. Both self-compatible but rely on pollinators for sexual reproduction. was nocturnal, settling moths (Thinopteryx nebulosa Porsica sp.). They foraged upside down from one side, carrying pollinaria eyes because curved lateral lobes labellum block movements these flowers. schindleri crepuscular hawkmoths (Eupanacra mydon Hippotion rafflesi), which carried between palpi while hovering front flowers taking nectar. The proboscis lengths both matched spur corresponding experienced a high level inbreeding depression. Interspecific pollination applying pollen grains stigmas ciliolaris, resulted low seed set. Differences morphology volume/concentration appear contribute segregating members guild some species. These findings offer new insights our understanding partitioning congeners Orchidaceae.

Language: Английский

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Rapid loss of plastid ndh genes in slipper orchids (Cypripedioideae, Orchidaceae)

Frontiers in Plant Science, Journal Year: 2025, Volume and Issue: 16

Published: April 22, 2025

The eleven plastid ndh genes encode for subunits of the (NAD(P)H dehydrogenase-like) complex, which mediates electron flow in photosystem I. loss plants was observed many different lineages Viridiplantae. In Orchidaceae, often associated with myco-heterotrophy. However, previous studies on this topic only a few slipper orchids were included. Our study aimed to analyze within Cypripedioideae, subfamily that is assumed be fully autotroph. Based comprehensive sampling 100 published plastomes representing 60% Cypripedioideae species, phylogenetic relationships revealed three levels. For family and levels, 57 66 genes, respectively, extracted concatenated Geneious, while genus-level phylogeny, complete used calculate maximum likelihood tree. Additionally, divergence time estimates performed illuminate evolutionary timeframe gene loss. prevalence, pseudogenization assessed visualized along trees. results confirmed four analyzed genera monophyletic could increase resolution compared studies. diversification started at about 30 Ma genus Paphiopedilum displaying most recent starting 11 showing speciation events around 4 Ma. rapid particularly Mexipedium, Phragmipedium illustrated. Furthermore, illustrated are an early stage degradation. Recent showed partial myco-heterotrophy (mixotrophy) far more common plant than originally assumed. our findings, we suggest possibility mixotrophic lifestyle (sub-)tropical should reevaluated. Further research regarding reasons behind provide better understanding ecological evolution Cypripedioideae.

Language: Английский

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Morphological and Ultrastructural Features of Selected Epidendroideae Pollen Dispersal Units and New Insights into Their Chemical Nature

Plants, Journal Year: 2024, Volume and Issue: 13(8), P. 1114 - 1114

Published: April 16, 2024

Orchidaceae display enormous diversity in their flower morphology, which is particularly evident pollen dispersal units (pollinia, pollinaria). The packaging of by elastoviscin leads to a great these morphologically and structurally complex units. Despite being one the most diverse angiosperm families, available palynological data on orchids remain limited sometimes contradicting. This study provides new insights into morphology ultrastructure five orchid species from subfamily Epidendroideae, using combined light, scanning electron, transmission electron microscopy. aim was compare elucidate chemical nature wall layers elastoviscin. Our light microscopy investigation demonstrated presence six tetrad types even within single pollinium, unique for orchids. application different staining methods confirmed assumed lipidic differences its contrast suggest mixture sticky materials with dissimilar compositions. affirmed that sporopollenin mostly restricted outer grains peripheral tetrads compact sectile pollinia, while inner exhibit highly reduced non-sporopollenin walls.

Language: Английский

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Organellar phylogenomics at the epidendroid orchid base, with a focus on the mycoheterotrophic Wullschlaegelia

Annals of Botany, Journal Year: 2024, Volume and Issue: unknown

Published: May 28, 2024

Abstract Background and Aims Heterotrophic plants have long been a challenge for systematists, exemplified by the base of orchid subfamily Epidendroideae, which contains numerous mycoheterotrophic species. Methods Here we address utility organellar genomes in resolving relationships at epidendroid base, specifically employing models heterotachy, or lineage-specific rate variation over time. We further conduct comparative analyses plastid genome evolution heterotrophs structural matK. Key Results present first complete (plastomes) Wullschlaegelia, sole genus tribe Wullschlaegelieae, revealing highly reduced 37 kb, retains fraction genes related autotrophs. Plastid phylogenomic recovered strongly supported clade composed exclusively species with branches. analysed mitochondrial gene sets, similar to those other studies using nuclear data, but placement Wullschlaegelia remains uncertain. conducted plastome among heterotrophic orchids, suite correlated substitutional changes relative autotrophic Lastly, investigated evolutionary matK, is retained few ‘late stage’ found evidence conservation despite rapid substitution rates both leafless Gastrodia. Conclusions Our reveal limits what can tell us on this part tree, even when applying parameter-rich heterotachy models. study underscores need increased taxon sampling across all three illustrates research addressing analyses.

Language: Английский

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Plastid genome evolution in leafless members of the orchid subfamily Orchidoideae, with a focus on Degranvillea dermaptera

American Journal of Botany, Journal Year: 2024, Volume and Issue: 111(7)

Published: July 1, 2024

Abstract Premise Leafless, heterotrophic plants are prime examples of organismal modification, the genomic consequences which have received considerable interest. In particular, plastid genomes (plastomes) being sequenced at a high rate, allowing continual refinement conceptual models reductive evolution in heterotrophs. However, numerous sampling gaps exist, hindering ability to conduct comprehensive phylogenomic analyses these plants. Methods Using floral tissue from an herbarium specimen, we and analyzed plastome Degranvillea dermaptera , rarely collected, leafless orchid species South America about little is known, including its phylogenetic affinities. Results The most reduced those among subfamily Orchidoideae. it has lost majority genes found leafy autotrophic species, structurally rearranged, similar gene content plastomes orchids. We strong evidence for placement within subtribe Spiranthinae using that explicitly account heterotachy, or lineage‐specific evolutionary rate variation over time. further relaxed selection on several correlations substitution rates other “traits” members Conclusions Our findings advance knowledge relationships paths genome orchids, experienced more independent transitions heterotrophy than any plant family. This study demonstrates importance collections comparative genomics poorly known conservation concern.

Language: Английский

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