大白菜雄性不育系小孢子发生的细胞形态学研究

Microsporogenesis of Several Male-Sterile Lines in Brassica rapa L.ssp. pekinensis

采用塑料半薄切片技术 ,在光学显微镜下系统地观察了大白菜同质异核、异质同核细胞质雄性不育系、细胞核雄性不育系及其相应保持系花药发育过程的细胞形态学特征。研究结果表明 :细胞核雄性不育系花药败育主要发生在减数分裂期 ,花粉母细胞不能发生正常的减数分裂 ;细胞质雄性不育系花药败育主要发生在四分体时期或小孢子单核期 ,表现为绒毡层细胞异常 ,四分体或小孢子败育。

Microsporogenesis of two cytoplasmic male sterile(CMS)lines 66A and 61A,one genic male sterile(GMS)line 76A and their maintainers was investigated cytologically by using plastic semi thin sections with light microscopy.The complete abortion of 76A occurred at the stage of meiosis,the pollen mother cells could not develop to form tetrads due to the abnormal meiosis meanwhile the tapetum cells degenerated prematurely.CMS 61A line formed abnormal tetrad.The callose wall did not degenerate and no microspores were released from the tetrad.At the same time,an abnormal morphology of the tapetum cells was observed,which showed either hypertrophy or a formation of periplasmdium.The inhibition of mosporogenesis of CMS 66A occurred at the uninucleate stage when the microspore failed to continue gametogenesis and abnormal vacuolation and rudimental exine were observed.The tapetum cells were abnormal with hypertrophy or forming periplasmdium.