牛角瓜花部综合特征与繁育系统  

Floral Syndrome and Breeding System of Calotropis gigantean

作　　者：刘鹏[1] 刘惠民[1] 王连春[1] 李璐[1] 郑元[1] 张太奎[1] 

机构地区：[1]西南林业大学林学院,昆明650224

出　　处：《园艺学报》2015年第10期2002-2014,共13页Acta Horticulturae Sinica

基　　金：林业公益性行业科研专项(201304810)

摘　　要：野外调查发现,牛角瓜（Calotropis gigantean）的自然坐果率较低,影响了利用其种子纤维的开发前景。研究了牛角瓜的传粉生物学,观察了云南元江牛角瓜居群的开花进程、花部特征和访花昆虫,检测了其花粉活力与柱头可授性,并对其进行了人工授粉辅助试验。结果表明：（1）牛角瓜花为聚伞形花序,花冠蓝紫色,花期全年,单花花期7-8 d,在开花整个过程中花粉一直保持较强活力且柱头具有可授性,花药一直低于柱头,由蜡质薄膜包裹的花粉粒形成花粉块,无法散落至柱头,花药和柱头间存在空间隔离。（2）牛角瓜的杂交指数为4,说明其繁育系统以异交为主,部分自交亲和,需要传粉者。（3）人工授粉试验显示,牛角瓜不能在柱头表面完成授粉,而是在柱头腔中,且存在一定的传粉限制;没有自发的自花传粉现象,在自然条件下也没有无融合生殖现象,人工异株授粉结实率比自花授粉结实率高。（4）昆虫借助足部特殊结构将花粉块移出并将花粉块通过花药裂口插入柱头腔中以完成授粉;牛角瓜访花昆虫共有10余种,传粉昆虫主要有膜翅目的黑小蜜蜂、圆柄木蜂和木蜂。花粉限制是牛角瓜坐果率低的主要原因,可通过放养传粉昆虫来提高牛角瓜的坐果率,从而增加其种毛纤维的产量。The low natural fruit set rates of Calotropis gigantean L. decreased the ecnomic application in fibers. The surveies on the blooming progress,floral traits,flower-visiting insects,pollen viabilities,stigma receptivity,and breeding system of the wild C. gigantean groups in Yuanjiang region of Yunnan,were performed（.1）The C. gigantean flowers had sympodium umbels,the hyacinthine corollas,blooming all the year round and the flowering phase of 7–8 d. Their pollen had strong vitalities and stigma possessed certain receptivity during the flowering. The anther height was lower than the stigma height. All pollen grains which were wrapped by the ceraceous thin film and formed the pollinaria could not scatter and fall on the stigma. Consequnently,there was the spatial isolation between the anther and the stigma（.2）The hybridization indexes of 4 indicated that the breeding was the outcrossing and partly self-compatible,and demanded the pollinators. That the pollination on the anther slit instead of the stigma had certainlimitations was surveyed through the test of the hand-pollinate on the C. gigantean.（3）The test on the hand-pollinate on the C. gigantean revealed that the pollination on the Stigmatic chamber rather than the stigma resulted in the limitiations to pollination. There were no spontaneous self-pollination phenomenon and no apomixis phenomenon under field conditions. The setting ratios of the artificial pollination surveyed on the outcrossing were higher than which surveyed on the self-pollination. Therefore,the setting rate differences between them verified the results of the hybridization indexes.（4）The insect moved out the pollinaria and inserted it into the Stigmatic chamber to finish the pollination,using their special body parts. More than ten kinds of flower-visiting insects were surveyed on the C. gigantean and the pollinating insects mainly were the Micr Micrapis andreniformis Smith,Xylocopa tenuiscapa and a specie of the Xylocopa family. Pollen limitation is the main reason of the low

关 键 词：牛角瓜 传粉生物学 花部特征 繁育系统 合蕊柱 花粉块 

分 类 号：S68[农业科学—观赏园艺]