小桐子繁育系统与传粉生态学研究

在野外定位观测小桐子花朵的功能形态特征、开花动态、传粉方式,用杂交指数(OCI)、花粉/胚珠比(P/O)、去雄、套袋、人工授粉等方法分别测定小桐子的繁育系统.结果显示:(1)小桐子是单性花,雌雄同株同序.雄花单花期2 d,雌花单花期5～8 d,雌花直径略大于雄花.(2)雄花开花后9 h内花粉活力较高,24 h后花粉活力明显降低,48 h后花粉基本散失活力;雌花柱头可授性在开花后4 d内最强,5～8 d可授性开始降低,第9天基本失去可授性.(3)传粉方式以虫媒传粉为主,为虫媒植物.(4)繁育系统检测结果为部分自交亲和异交,需要传粉者活动才能完成授粉过程.

Breeding System and Pollina tion Ecology in J a tropha cu rcas

Plant flowering and breeding characteristics are important to understand reproduction of plant population. Flowering characteristics and pollination ecology of Jatrapha curcas were investigated in Yuanjiang County,Yunnan Province. The breeding system,pollen-ovule ratio(P/O)and pollen viability were determined.The results were as follows:(1)Jatropha curcas was monoecious, The plant produced flowers in dichasial inflorescences. Normally, the flowers were unisexual, and male and female flowers were produced in the same inflorescence. In a few, only male flowers were produced in an inflorescence, and fruit were produced only through pollination between different flowers from the same or different plant. The 1ife span of the male flower was about 2 days.The life span of the female flower was about 5 - 12 days.The diameter of female flower was bigger than that of the male flower slightly.(2)The pollen viability of male flower was relatively high in 9 hours after blooming and get low 33 hours later. The pollen hardly had any viability after 48 hours.The stigmatic receptivity of female flower was strong during 1^st- 4^th day and began to decline on 5^th day. On 9^th day, stigma completely lost its receptivity.(3) The effective pollination way of J. curcas was insect pollination.(4)J. curcas was out-crossing, partly self-compatible,requiring pollinator.