小麦种质资源BJ399抗条锈病基因的分子标记定位

条锈病是影响小麦产量和品质的一种世界性病害。种质资源BJ399对小麦条锈病具有良好的苗期和成株期抗性,为明确其条锈病抗性基因,利用BJ399和高感条锈病品种铭贤169杂交,获得BJ399/铭贤169的F_1、BC_1和F_2代分离群体,并利用我国当前流行的条锈菌生理小种条中34号(CYR34)进行温室苗期抗条锈性鉴定和遗传分析。结果表明,BJ399对CYR34的抗性由1对显性基因控制,暂命名为 YrBJ399。筛选到3个与目的基因连锁的SSR标记Xwmc296、Xgwm425和Xgwm558,且3个标记位于抗病基因的同一侧,距离目的基因最近的标记为Xwmc296,其遗传距离为9.5 cM,标记Xgwm425和Xgwm558与目的基因 YrBJ399的遗传距离分别为14.3 cM和18.0 cM,并初步将抗病基因定位于小麦染色体2AS上。根据抗病基因来源和染色体定位结果推测, YrBJ399可能是一个抗条锈病新基因。

Molecular Mapping of Stripe Rust Resistance Gene in Wheat Germplasm BJ399

Stripe rust, caused by Puccinic striiformis f. sp. tritici(Pst), is a serious worldwide disease affecting yield and quality of wheat(Triticum aestivum L.). Our previous studies have shown germplasm BJ399 has greater resistance to CYR34 at seedling and adult stages. In order to reveal the genetic basis of BJ399 resistant to stripe rust, F₁, BC₁ and F₂ segregating population derived from the cross of BJ399/Mingxian 169 were used as materials and inoculated with Chinese Pst race CYR34 in the greenhouse, in Lanzhou, Gansu province.The result showed that BJ399 was resistant to CYR34, whereas Mingxian 169 was highly susceptible to CYR34. Genetic analysis indicated that the resistance of BJ399 to stripe rust was conferred by a single dominant gene, temporarily designated as YrBJ399. Three SSR Markers,Xwmc296,Xgwm425 and Xgwm558 were identified to be linked to the resistance gene as they were all located on the same side of the YrBJ399. The closest linked flanking marker was Xwmc296, with genetic distance of 9.5 cM, and Xgwm425 and Xgwm558 were linked to YrBJ399,with genetic distances of 14.3 cM and 18.0 cM, respectively.Based on the positions of the SSR markers on the wheat chromosome, YrBJ399 was located on chromosome 2AS. According to the origins and chromosome locations, YrBJ399 is likely to be a novel gene against stripe rust.