Study on Spontaneous Self-pollination Mechanism of Asarum sieboldii

华细辛自发自交传粉机制研究(英文)

[Objective] The aim of this study was to investigate spontaneous self- pollination mechanism of Asarum sieboldii. [Methed] Through field observation and manual controlling test under the cultivated condition, the whole flowering process of Asarum sieboldii belonging to Asarum subgenus Heterotropa was thoroughly ob- served to investigate its pollination mechanism. [Result] Asarum sieboldii is a kind of species dominated by spontaneous self-pollination. Its female flower became mature firstly, and the duration of single flower ranged from 3 to 4 d. The first day was fe- male phase duration, and the stigmas could receive foreign pollen, while stamen fila- ments bent down towards the base of calyx tube with 90°, and anther had no crack. During the following 2 days, two cycles of stamens erected subsequently, while an- thers became dehiscent and naturally contacted with stigma at the same time, so spontaneous self-pollination was finished. Artificial self-pollination and out-crossing test had proved that the out-crossing of Asarum sieboldii were all fertile with seed setting rate of 100%. Emasculation by bagging test had suggested that Asarum sieboldii had no parthenocarpy and apomixes. [Conclusion] Asarum sieboldii belongs to sub- genus Heterotropa, but its pollination mechanism is similar to that of subgenus Asarum.

【目的]对华细辛自发自交传粉机制进行研究。[方法1通过野外观察和栽培条件下人工控制试验，对细辛属华细辛的整个开花过程进行了详细的观察，对其传粉机制进行研究。[结果]华细辛是一种以自发自交为主要传粉方式的物种。其花雌性先熟，单花期一般为3~4d，第1天为雌性期，柱头可以接受外来花粉，雄蕊花丝呈90°下弯，花药不开裂；第2及第3天，两轮雄蕊依次上举，花药依次开裂，并与柱头发生自然接触，完成自发自交传粉。人工自交和异交试验证明，华细辛的异交均是可育的，结实率均达到100％。去雄套袋试验表明华细辛不能单性结实，也没有无融合生殖现象。[结论]华细辛是杜衡亚属植物，但是其传粉机制与细辛亚属植物很相似。