2004-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/694671摘要：顯著的花可以吸引傳粉者前來，而若這些花沒有了這些明顯的構造，它們的結果率可能就會因沒有傳粉者而下降。我們希望能研究一個台灣獨特的例子-玉葉金花，說明在失去了重要的顯著花部構造之後，植物是如何還生存下來的。玉葉金花（Mussaenda pubescens）是台灣低海拔中常見的植物之一，它是一個雌雄異株的植物。玉葉金花常可以見到花萼其中的一個裂片尖端膨大成一個外形類似葉子、但顏色為白色或紅色的構造，稱為葉狀萼片（calycophylls, 或floral semaphylls）。而玉葉金花名稱的由來，即源於它的花序中黃色的花瓣和白色的葉狀萼片而來。這些葉狀萼片不管在細胞形狀或細胞排列上，都與正常的花瓣類似，加上有著顯著的顏色，一般皆認為這些葉狀萼片在功能上與花瓣無異，而與吸引有效傳粉者有關。在前人與我們的觀察中發現，在台灣北部及東北部的玉葉金花族群中，都沒有膨大的花萼構造。而我們已經觀察到它們的結果率其實不低，因此我們希望針對這些沒有膨大花萼的玉葉金花和正常的玉葉金花進行生殖生物學的研究，以瞭解它們的生存策略。我們選擇了台北縣樹梅坪，苗栗三義，和屏東南仁山的三個族群進行研究。其中只有樹梅坪<br> Abstract: 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 propose to perform a detailed survey for floral morphology, nectar secretion pattern, and crossing experiment, among the populations with and without enlarged semaphylls. We will also perform a survey for genetic divergence and phylogenetic analysis using molecular markers among three study sites of M. pubescens. This will help to understand the degree of divergence among individuals with different semaphyll types in M. pubescens, and provide information for taxonomic status of this potential species complex. We will use randomly amplified polymorphic DNA (RAPD) approach to examine the population structure and to measure genetic distance among individuals. The two-year experiment is necessary for conducting long-term observation.玉葉金花生殖生物學族群遺傳Mussaenda pubescensreproductive biologypopulation genetics