芸苔属脱外壁花粉作为研究花粉萌发的新实验系统

脱外壁花粉的分离与人工萌发已在芸苔属(Brassica L.)中取得成功。由于其缺乏外壁与萌发沟这一特点,脱外壁花粉是研究花粉萌发的有用的实验系统。作者重点研究了脱外壁花粉分离与萌发过程中有关极性形成、萌发位点预定及新壁的合成等问题。结果表明在外壁脱离之前花粉已经活化并预先建立了极性;脱外壁后的萌发位点仍位于原萌发沟处;在萌发位点处合成的新壁可能起限定花粉管直径的作用。由此推论,脱外壁花粉可在花粉生物学研究中广泛加以应用。

BRASSICA DE-EXINED POLLEN AS A NEW EXPERIMENTAL SYSTEM FOR STUDYING POLLEN GERMINATION

Exine deprived pollen only coated with inline has been isolated and artificially germinated in Brassica L. In view of the lack of exine and germ furrows, the de-exined pollen is an interesting experimental system for studying pollen germination. This report focuses on the microscopic and ultrastructural changes in the aspects of polarization, predetermination of the germination site and new wall synthesis during the course of isolation and germination of the de-exined pollen. It was shown that the de-exined pollen was already in an active state and had established its polarity and germination sites prior to exine detachment. The germination sites were still localized at the region of the previous germ furrows even after exine detachment. The new wall deposited at the germination sites appeared to have an important morphogenetic role in setting a limit to the size of pollen tube diameter . These results support our assumption that the de-exined pollen may have an extensive application in the research of pollen biology.