斜翼致濒原因探讨

An investigation on the probable causes for the endangerment of Plagiopteron suaveolens Griffith

斜翼是一个濒于灭绝的单型科植物。国内产地由于植被破坏导致居群及个体数量十分稀少。斜翼花开后自行脱落，胚囊成熟后逐渐退化、败育；花粉败育率为３８％。有性生殖障碍是该种植物个体数量稀少的主要原因，其生殖障碍可能主要是传粉和授精不能正常进行，并导致胚囊败育。应严格保护现有植株，并进行分株移植，以保存该物种。

Plagiopteron suaveoleas is extremely endangered in the wild and would become extinct if proper protective and propogational measures are not taken. It is scattered in Burma, Thailand and China. The population in China has flowers in blooming throughout a year, but flowers fall after blooming, and very few fruits and no seeds have been found to develop. Embryologically the plant develops normally until the organization of eight-nucleate embryo sac, but afterwards the antipodals secondarily increased, and the elements of embryo sac disintegrates finally, hence embryo sac becomes empty. The probable failure in successful pollination and fertilization leads to the collapse of embryo sac. Stained with malachite green-acid fuchsin -orange G,38 per cent of pollen grains are fo und to be sterile and this is possibly one of sexual propogation barriers. Inlocalities the recent massive clearing of vegetation for cultivation of economic plants leads in turn to the clearing of plants and this species becomes extremely endangered.