大白菜hau胞质雄性不育系的鉴定及不育相关基因结构分析

 采用染色体压片法和形态观察法，对大白菜hau胞质雄性不育材料6w-9605A的2个遗传世代（F₁和BC₆）的染色体数和花器官进行鉴定。结果表明：F₁染色体数为28条；BC₆染色体数为20条，与白菜的染色体数相同。6w-9605A的花药呈三角形，干瘪无花粉，败育彻底。利用芸薹属作物雄性不育基因线粒体保守序列设计3对引物，在6w-9605A中扩增出867 bp的片段。基因预测显示，在线粒体基因atp6的下游产生1个新的开放阅读框为orf288，与目前报道的芸薹属作物细胞质雄性不育相关基因orf224、orf138等均不相同，这种新的基因结构特点极有可能就是大白菜hau胞质不育系6w-9605A产生不育的原因。

Characterization of the Chinese Cabbage hau Cytoplasmic Male-sterile Line and Sequence Analysis of the Fertility-related Gene

The male-sterility of the Chinese cabbage(Brassica campestris L. ssp. pekinensis)line 6w-9605A,a cytoplasmic male-sterile line,was studied in this research. Chromosome squashing revealed that the chromosome numbers in the F1 and BC6 of 6w-9605A were 28 and 20,respectively,and morphologic observation in the BC6 of 6w-9605A showed that the anthers of this line were degenerated and completely abortive. Further,primers were designed based on the conserved sequence of known cytoplasmic male sterility genes in the Brassica species,and a new open reading frame(ORF)of 867 base pairs was amplified from 6w-9605A. Sequence analysis showed that this ORF located downstream from the mitochondrial gene apt6 and was predicted as orf288. Sequence alignment demonstrated that the ORF is different from the sterile genes of pol CMS and ogu CMS,and it may cause the sterility of 6w-9605A.