02495nas a2200289 4500008004100000245011400041210006900155260001200224300001300236490000700249520167700256653001301933653001001946653001701956653002301973653001401996653001702010653001602027653001402043653001602057653002702073653001502100653001402115100001402129700001202143856005002155 2017 eng d00aMultiple factors contribute to reproductive isolation between two co-existing Habenaria species (Orchidaceae)0 aMultiple factors contribute to reproductive isolation between tw c11/2017 ae01885940 v123 a

"Reproductive isolation is a key feature that forms barriers to gene flow between distinct plants. In orchids, prezygotic reproductive isolation has been considered to be strong, because their associations with highly specific pollinators. In this study, the reproductive ecology and reproductive isolation of two sympatric Habenaria species, H. davidii and H. fordii, was investigated by floral phenology and morphology, hand-pollination experiments and visitor observation in southwest China. The two species were dependent on insects for pollination and completely self-compatible. A number of factors have been identified to limit gene flow between the two species and achieved full reproductive isolation. Ecogeographic isolation was a weak barrier. H. fordii and H. davidii had completely overlapped flowering periods, and floral morphology plays an important role in floral isolation. The two species shared the same hawkmoth pollinator, Cechenena lineosa, but the pollinaria of the two orchids were attached on different body parts of pollinators. Prezygotic isolation was not complete, but the interspecific pollination treatments of each species resulted in no seed sets, indicating that unlike many other orchid species, in which the postzygotic reproductive isolation is very weak or complete absence, the post-zygotic isolation strongly acted in the stage of seed production between two species. The results illustrate the reproductive isolation between two species involves multiple plant life-history stages and a variety of reproductive barriers can contribute to overall isolation."

10aCECHETRA10aCHINA10aFLORAL SCENT10aGAS CHROMATOGRAPHY10aHABENARIA10aMACROGLOSSUM10aORCHIDACEAE10aPHENOLOGY10aPOLLINATION10aPOLLINATOR SPECIFICITY10aSPHINGIDAE10aWORLDMAP11 aZhang, W.1 aGao, J. uhttps://doi.org/10.1371/ journal.pone.0188594