台灣產玉葉金花生殖生物學與族群遺傳之研究

Floral display is critical to attract pollinators for animal-pollinated plants. Loss of visual signal
of flowers may well decrease the reproductive success, and eventually lead to extinction of such
plant. We would like to investigate a unique case in Taiwan’s Mussaenda pubescens, in which some
populations may have survived the loss of showy floral signal. Mussaenda pubescens Ait., a
member of Rubiaceae, has a distinct enlarged calyx-lobe which is generally thought to attract
pollinators like butterflies. The high-contrast visual signals have been shown to be essential for high
fruit sets in another Mussaenda species, M. parviflora. Based on our survey, we found many of the
M. pubescens populations in northeastern Taiwan lack the showy semaphyll. The preliminary
observation showed that these individuals are able to bear fruits, suggesting that cross-pollination
still occurs and they somehow overcame the deficiency in pollinator attractants. We performed a
survey for floral morphology, nectar secretion pattern, and SEM observation among the populations
with and without enlarged semaphylls. We also performed a phylogenetic analysis using nrITS
sequences among three study sites of M. pubescens. This will help to understand the systematic
identities with different semaphyll types in M. pubescens,. The original plan is to have a two-year
experiment for long-term observation. Since this grant is funded only for one year. We have
preliminary data shown here.