极危植物毛果木莲花粉败育及其结籽率研究

 毛果木莲是云南特有种,也是被IUCN评估为极危种(CR)的濒危植物.通过石蜡切片技术与显微观测技术对极危物种毛果木莲花粉败育、花粉胚珠比与结籽率进行研究,发现该物种花粉败育率达29%,正常花粉胚珠比>4527,结籽率聚合果达到34%,单果达44%.结合花粉胚珠比,初步认为该物种交配系统为专性异交类型,花粉败育对结籽率低影响不大.结合该物种野外种群调查,初步分析认为该物种的选择性败育特性是适应外界环境资源有限的一种生殖保障策略.

Study on pollen abortion and seed setting ratio in Manglietia hebecarpa C.Y. Wu et Law,a critically endangered plant in Yunnan Province

In order to know about the endangered reason of the reproductive characters in Manglietia hebecarpa C.Y. Wu et Law,a CR species(IUCN),only distributed in Yunnan Province,we studied the sterile pollen,pollen-ovule ratio and seed setting rate of this species by paraffin section and microscopic observation techniques.The random samples were taken from its natural population in Pingbian county in Yunnan province.We found that the pollen abortion reaches 29%,normal pollen-ovule ratio are greater than 4527,seed setting ratio of follicle is 44% and 34% of aggregate fruit.The mating system was obligate outbreeding type according to pollen-ovule ratio and the seed-setting ratio was not high compared with the other species and is not straightly related with pollen abortion.With field survey and analysis,we found the plant natural population was very small and segregative,and we thought the selective abortion of androecium or gynoecium was one kind of reproductive adaption for the external environment stress to some extent in Manglitia hebecarpa.