长春蒲公英花部综合征与繁育系统研究

The Research of Obligate Apomixis Characteristic in Dandelions(Taraxacum junpeianum)

通过田间观察,运用杂交指数、花粉胚珠比、授粉套袋等实验方法,对长春蒲公英花部综合征及繁育特性进行初步研究。结果表明:种群花期集中在5月,单花寿命1～2 d,聚药雄蕊,先熟,柱头被包裹在花药筒内,药室内向开裂,在花柱快速伸长突破药室的过程中,花柱毛将药室内的花粉粒带出。柱头经历棒状-Y型-羊角状3种形态,柱头开裂后才具有可授性。杂交指数≥4,P/O值为1 444,结合人工套袋和授粉试验的结果,确定长春蒲公英具有极高的无融合发生率。试验中发现长春蒲公英雄性不育系,可正常结籽,确定长春蒲公英为专性无融合生殖。

To investigate the reproductive characteristics of T. junpeianum, we have done several researches which in aspect of mating system, pollen activity, pollen tube germination and embryo sac development. These results revealed that the pollen fertility of T. junpeianum was only 20.6% , self-pollen which in stigma cannot germinate ,whereas pollen which rising from cross pollination can germination instead growth of the plant was slow. Before the pollen tube reached the ovary, it had stopped growing and then disappeared. When develop- ment of the embryo sac be observed, it had formed proembryo before inflorescence blooming. By investigate the mating system, we found that T. junpeianum owns a very high rate of apomictic;besides, male sterile line was founded,which was formed normal seeds. In conclusion, T. junpeianum owns obligate apomixes reproductive characteristic.