青阳参花部特征及其传粉适应性

对青阳参花（Cynanchum otophyllum）部综合特征、访花昆虫种类、访花行为及传粉过程进行了研究，结果表明，青阳参花结构复杂，两个子房基部离生、花柱联合与雄蕊形成合蕊柱，柱头表面被邻近花药的侧翼紧密包围形成5个柱头腔。青阳参的花粉形成独特的花粉块，一次传粉过程可以转运大量的花粉。东方蜜蜂（Apis cerana）是青阳参的主要传粉昆虫，其传粉包括两个过程：（1）当蜜蜂的口器或足插入着粉腺的槽口后借助蜜蜂的力量将花粉块从花上拔起；（2）当蜜蜂再次访花时将携带的花粉块插入其中一个柱头腔。花粉块里面的花粉粒住柱头腔中萌发出花粉管，然后沿着花柱道向下生长最后进入子房。在整个花期仡粉保持有相对较高的生活力，而其柱头可授性则在7天后逐渐降低。

The Floral Syndrome and Its Pollination in Cynanchum otophyllum (Asclepiadaceae)

This paper studied on the floral syndrome of Cynanchum otophyllum, visiting insects and their foraging behavior. The results showed that the floral morphologies were complex. Two separate ovaries were united by their styles to form a gynostegium with anthers. The stigmatic surfaces were enclosed by the tightly abutting wings of adjacent anthers to produce five stigmatic chambers. C. otophyllum possessed pollinia, which permited the transfer of hundreds of pollen grains at a time. Honeybees （Apis cerana Fabricius） were primary, pollinators. The process of C. otophyllum pollination was： （1） removal of a pollinarium： when the groove in the eorpuseulum catched on mouthparts or legs of honeybees and was forcibly pulled from the flower, and （2） insertion of a pollinium： when a pollinium lodged in a stigmatic chamber. Following successful insertion, the pollens geminated within the stigmatic chamber and pollen tubes subsequently grew down the stylar canal and finally entered the ovaries. The durable covering of pollinia allowed a long residence time on pollen viability, so the pollen could remain a relatively high viability in the flower period. Stigma receptivity, however, decreased gradually over the seven-day life span of flowers.