小麦种质WS4-8苗期抗条锈性遗传分析及分子作图

Genetic Analysis and Molecular Mapping of Seedling Stripe Rust Resistance Gene in Wheat Somaclone 4-8

条锈病是小麦生产中的主要病害之一,研究和利用抗病种质是小麦抗条锈病育种的基础。为明确小麦体细胞无性系4-8(WS4-8)的抗条锈病基因及其遗传规律,用条锈菌生理小种CYR33对WS4-8和感病品种铭贤169及其杂交后代群体进行了苗期接种鉴定和抗条锈基因遗传分析。结果表明,WS4-8对CYR33表现抗病,其抗性由1对显性基因控制。利用BSA法对构建的F2代遗传作图群体进行了SSR标记分析,标记Xgpw5281、Xcfd35和Xgwm341与抗性基因具有连锁关系,且都为共显性标记,与抗病基因之间的遗传距离分别为6.8、7.2和21.8cM。根据作图结果,将WS4-8所携带的对CYR33的抗条锈病基因定位于小麦3DS染色体上。基于该基因的作图位置与分子标记结果,认为该基因可能是一个新的抗条锈病基因,暂命名为YrWS4-8。

Stripe rust,caused by Puccinia striiforrnis f. sp. tritici （PST）,is one of the most destruc- tive diseases of wheat （Triticum aestivum L. ） worldwide,including China. Detection and application of the resistance germplasm is the base for developing resistant cultivar. In order to identify and tag the new gene resistant to stripe rust in ＂wheat somaclone 4-8＂ （WS4-8, derived from Yongliang 4 by immature embryo tissue culture）,F1 and F2 populations from the cross of WS4-8/Mingxian 169 were inoculated with Chinese PST race CYR33 at seedling stage in green house. Genetic analysis indicated that the resistance to CYR33 in WS4-8 was conferred by a single dominant gene,temporarily designat- ed as YrWS4-8. SSR analysis showed that three co-dominant SSR markersXgpw5281, Xcfd35 andXg wm341 located on the chromosome 3DS were linked to YrWS4-8. Based on the gene location and mo- lecular marker detection results,it was suggested that the gene could be a newly discovered stripe rust resistance gene.