大白菜核雄性不育两用系小孢子发生的细胞形态学研究

Microsporogenesis of Nuclear Male Sterile Chinese Cabbage(Brassica campestris ssp. pekinensis)

大白菜核型雄性不育两用系小孢子发生过程的细胞形态学观察表明，雄性不育株小孢子的败育发生在四分体时期。由于绒毡层细胞异常膨大，挤压四分体，四分体不分离产生四分小孢子，从而不能形成正常的花粉粒而导致败育。

Microsporogenesis has been examined in nuclear male sterile Chinese cabbage using light microscopy. Development of male sterile anther was silimar to male fertile anther up to the tetrad stage·After this stage,the tapetal cells became larger and pressed tetrads tightly and teterads did not segregated to form microspores.It is not clear whether the abortion of the tetrads stimulates proliferation of the tapetal cells or the proliferating tapetum actually interferes with microspore development,thereby causing degeneration.