State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China.
College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China.
J Appl Genet. 2020 Dec;61(4):477-488. doi: 10.1007/s13353-020-00570-8. Epub 2020 Jul 26.
Genic male sterility (GMS) is an effective pollination control system applied in the hybrid breeding of Brassica napus L. Shaan-GMS is a spontaneous mutant of dominant GMS in B. napus. In this research, anther abortion in the homozygous two-type line 9A15AB derived from Shaan-GMS was characterised with the combined use of light microscopy and transmission electron microscopy. Results indicated that the most striking differences between the fertile and sterile plants occurred in the tapetum in the early microsporocyte stage. In sterile plants, the tapetal cells were irregularly arranged, multi-layered and occupied the growing space of microsporocytes. When entering into meiosis, the tapetum cells degraded and the cytoplasm fused. Some oval monolayer or bilayer membrane organelles existed in the tapetal cells in sterile anthers. Mitochondria in the tapetal cells were abnormal, and middle layer cells degraded early. Pollen mother cells of Shaan-GMS degenerated at the start of meiosis and ceased at the anaphase I stage, with no dyads or tetrads formed. The combined effects of the abnormal development of the tapetum, the middle layer cells and meiosis lead to male sterility in Shaan-GMS. Inheritance of male sterility of Shaan-GMS is controlled by a monogenically multiallelic locus with three different alleles (Ms, ms and Mf), with a relationship expressed as Mf > Ms and Ms > ms. The findings help lay the foundation for illustrating the mechanism of male sterility and the utilisation of Shaan-GMS in rapeseed.
基因雄性不育（GMS）是一种有效的授粉控制系统，应用于甘蓝型油菜杂种优势的培育。陕 GMS 是甘蓝型油菜显性 GMS 的自发突变体。本研究采用光镜和透射电镜相结合的方法，对源自陕 GMS 的纯合二型系 9A15AB 的花药败育进行了研究。结果表明，在早期小孢子阶段，可育和不育植株之间最显著的差异发生在绒毡层。在不育植株中，绒毡层细胞排列不规则，多层排列，占据小孢子的生长空间。进入减数分裂时，绒毡层细胞降解，细胞质融合。不育花药的绒毡层细胞中存在一些椭圆形单层或双层膜细胞器。绒毡层细胞中的线粒体异常，中层细胞早期降解。陕 GMS 的花粉母细胞在减数分裂开始时退化，停止在后期 I 阶段，没有二分体或四分体形成。绒毡层、中层细胞和减数分裂的异常发育共同导致了陕 GMS 的雄性不育。陕 GMS 雄性不育的遗传由一个单基因多等位基因座控制，有三个不同的等位基因（Ms、ms 和 Mf），表现型为 Mf > Ms 和 Ms > ms。这些发现为阐明雄性不育的机制以及在油菜中的应用奠定了基础。
