小麦花粉致死基因Ki的SSR标记分析

SSR Markers Analysis of Pollen Killing Gene Ki in Wheat

小麦雄性不育主要是通过花粉的败育表现,其不育材料对小麦杂种优势的利用研究具有重要意义和价值,国外研究表明,某些特定普通小麦品种间杂交F1表现的花粉部分不育现象,受控于核基因组花粉致死基因Ki,为了筛选小麦花粉致死基因Ki的连锁标记,利用现代分子生物学技术通过定位该基因,克隆出花粉致死基因连锁标记片段,为小麦雄性不育种质材料的转育提供有效的选择标记。对小麦花粉致死基因Ki进行了分子标记定位,以‘中国春’和澳大利亚春小麦品种的BC1F1代作为定位群体,利用分离群体分组分析法(BSA)对位于小麦6B染色体上85对SSR引物进行多态性筛选,具有多态性的引物再通过BC1F1定位群体进行验证,从中筛选出与目的基因连锁的2个SSR标记Xgwm626和Xgpw4138。运用Mapmaker 3.0软件进行连锁分析。结果表明,Xgwm626和Xgpw4138与Ki基因的遗传距离分别为9.2 c M和6.9 cM,且2个SSR标记位于目的基因两侧,并将Ki定位于小麦6BL染色体上。研究结果为Ki基因的分子标记辅助选择和进一步精细定位奠定了基础。

Wheat sterile mainly expressed through the performance of pollen abortion. The study on infertility material of wheat heterosis has great significance. Overseas research shows that among certain parts of the common wheat hybrids F1, pollen sterility is controlled by nuclear genome of pollen killing gene Ki. In order toscreen linked markers of pollen killing gene Ki in wheat, modern molecular biology techniques were used tolocate the gene, clone fragment pollen lethal gene linked markers, provide an effective selection marker fortransformation of male sterility in wheat germplasm and study the molecular markers of pollen killing gene Ki in wheat. A BC1F1 population derived from the crossing between Chinese spring wheat and Australian springwheat was used for molecular mapping of Ki gene. The sterile and fertile near isogenic bulks was constructedfrom the above BC1F1 population. By using Bulked Segregant Analysis（BSA） method, 85 SSR primers on wheat6 B chromosome were screened, and two SSR markers（Xgwm626 and Xgpw4138） were found to be linked to Ki gene. These markers could be used in fine mapping of Ki and marker-assisted selection. Two SSR markers Xgwm626 and Xgpw4138 located on the long arm of chromosome 6B were linked to Ki, and their geneticdistances to Ki were 9.2 c M and 6.9 c M, respectively, indicating that these two markers could be used inmolecular-assisted breeding.