以铭贤169为遗传背景的小麦抗条锈病基因YrJu4的单基因近等基因系构建

Development of near isogenic lines with a single wheat stripe rust resistance gene YrJu4 in the background of Mingxian 169

条锈病是我国小麦种植区域重要的流行病害之一。病原菌群体中流行小种改变常导致抗病品种"丧失"抗锈性。构建单基因近等基因系对于抗条锈病基因鉴定分析、病原菌小种毒性变异监测具有重要的意义。本研究以高感病冬麦品种铭贤169为遗传背景、尤皮Ⅱ号为抗条锈病基因供体转育构建单基因近等基因系。采用基因推导并结合遗传分析方法,明确铭贤169*6/尤皮Ⅱ号的近等基因株系N27和N36所含抗条锈病基因的个数,并利用与YrJu4紧密连锁的SSR分子标记对鉴定株系进行分子检测。基因推导分析结果表明,N27和N36近等基因株系可能含有YrJu3或YrJu4,或YrJu3+YrJu4。用菌系CY17和CY26对利用N27和N36株系构建的群体进行遗传分析,发现这两个株系对CY17和CY26的抗性都是受1对显性基因控制。分子标记检测结果表明,N27和N36株系都可扩增出与来源于抗性基因供体尤皮Ⅱ号的YrJu4相同的型带。因此,来源于小麦条锈菌鉴别品种尤皮Ⅱ号的抗病基因YrJu4已成功转育到轮回亲本冬麦品种铭贤169中,N27和N36株系是以铭贤169为遗传背景的YrJu4的单基因近等基因系,即铭贤169*6/YrJu4。

Stripe rust is one of the important epidemical diseases in the wheat-grown areas in China. The change of dominant races in the pathogen population usually results in that resistance varieties‘loss’ their resistance capability. Developing a set of near isogenic lines（NILs） with a single wheat stripe rust resistance gene is essential for characterization of stripe rust resistance genes in wheat cultivars and monitoring the change of virulence in the pathogen population. In this study,highly susceptible winter variety Mingxian 169 was used as recurrent parent and Jubilejina 2 as the resistance gene donor for developing a set of NILs. Through resistance gene postulation combined with genetic analysis,the resistance gene（s） contained in near isogenic lines N27 and N36 was deduced,and confirmed by PCR with two primers,SSR markers closely linked with YrJu4. The genetic analysis revealed that lines N27 and N36 may contain YrJu3 or YrJu4,or YrJu3 plus YrJu4,and the stripe rust resistance of both lines N27 and N36 to CY17 and CY26,respectively,is controlled by one dominant gene. The PCR results confirmed that the amplicon from Jubilejina 2 with resistance gene YrJu4 was in the same size of thosefrom lines N27 and N36. Therefore,the stripe rust resistance gene YrJu4 from differential variety Jubilejina 2 was successfully transferred into the winter-type recurrent parent,Mingxian 169,and both lines N27 and N36 developed are NILs of Mingxian 169＊ 6/YrJu4,with a single resistance gene YrJu4.