中文摘要：

通过野外观察，运用人工授粉、噻唑蓝（MTT）、柱头压片等方法，对广玉兰开花动态、花粉活力、柱头可授性、雌雄异熟机制进行研究。结果表明：1）在广玉兰为期5—6d的单花开花过程中，存在二次开合现象；2）广玉兰开花后花粉活力随开花进程逐渐减弱，初次开放阶段是柱头最佳可授期，对异株异花、同株异花及自花授粉皆具可授性；3）广玉兰自花授粉在柱头表面及花柱道内不发生自交不亲和，并可座果结籽，具有自交亲和的潜在可能；4）从繁育角度推测，玉兰亚属可能比木兰亚属更原始；5）广玉兰的雌性先熟是通过主动控制花药开裂时间，降低雌雄功能干扰，有效减少自花授粉。

英文摘要：

Through field investigation, we studied the flowering dynamics, pollen viability, stigma receptivity and dichogamous mechanism of Magnolia grandiflora by bagged artificial pollination, thiazolyl blue （MTT） dyeing, stigma tabletting and other methods. The results showed that： 1） during the five-six days flowering period of an individual flower, two-times opening-closure flowering was observed; 2） Pollen viability decreased over flowering stage, and the optimal pollination period was in the first opening stage when the stigmas were receptive to xenogamous, geitonogamous and self pollinations ; 3） After selfpollinating, self-incompatibility did not appear on the stigma surface nor in the styles, and fruits and seeds could be set, indicating that M. grandiflora is self-compatible to some degree; 4） From the perspective of reproduction, we infer that subgenus Yulania is more primitive than subgenus Magnolia; 5） Protogyny in M. grandiflora lies in a mechanism that determines the anther dehiscence stage, thus reducing self-pollination and interference between pollen and stigmas.