甘蓝型油菜双显性细胞核雄性不育系Shaan-GMS雄配子发育观察

Cytological observation of male gametogenesis development of digenic dominant Shaan-GMS in Brassica napus

采用常规压片与冰冻切片两种方法,观察甘蓝型油菜不育系Shaan-GMS的不育株与可育株小孢子母细胞减数分裂和小孢子发育过程,以阐明小孢子败育时期和细胞学特征。植株表型上,花期可育株与不育株花器官差异较大:不育株花丝较短,花药小且干瘪,微粉或无粉,淡黄色;细胞学观察结果显示不育株的花粉母细胞能够进行正常的减数分裂,形成四分体,但在单核期开始发生异常。主要表现为小孢子从四分体中释放后无法形成正常的小孢子外壁,随后小孢子外壁、内容物和绒毡层均提早降解,只剩下空壳与残渣,药室也随之萎缩变形,最终导致花粉败育。上述结果说明Shaan-GMS为单核败育类型,可能是一个细胞核雄性不育新材料。

DDGMS （digenic dominant genic male sterile） microsporogenesis was investigated using Shaan-GMS rapeseed （Brassica napus L.） by squashing and freezing the anther. In sterile plants,the anther was shriveled,dehydrated and small with short filaments. Cytological observation revealed a normal tetrad stage of anther. Pollen aborted at the uninucleate microspore stage when tetrads exine aborted after microspores released. Exines and cytoplasm of microspores as well as tapetum cells prematurely degenerated. Only debris left subsequently in the distorted and shrunk locules. The results suggested rapeseed Shaan-GMS to be a new type of DDGMS.