中国小麦条锈病菌CYR32和CYR33的毒性及基因型多样性

Virulence and genotypic diversity of wheat stripe rust races CYR32 and CYR33 in China

为明确我国小麦条锈病菌当前主要流行生理小种CYR32和CYR33的毒性及基因型特征,从全国11个省(区)随机选取29个CYR32菌株和39个CYR33菌株,利用近等基因系及辅助鉴别寄主对其进行毒性鉴定,利用SSR分子标记技术对其进行基因型分析,并对其进行聚类分析。结果显示,CYR32和CYR33菌系各有17种毒性表型,而且在抗病基因Yr2、Yr17、Yr27、Yr32、Yr43、Yr Sp、Yr Exp2、Yr28、Yr V23上都发生了毒性分化,CYR32和CYR33菌系的多样性指数分别为0.089、0.097;CYR32和CYR33菌系的香农信息指数均值分别为0.44和0.45;当相似性系数为0.93时,CYR32和CYR33菌系分别被聚为5个和8个毒性类群;当相似性系数为0.84时,CYR32和CYR33菌系分别被聚为10个和16个基因型类群。表明在中国鉴别寄主上具有相同毒性谱特征的CYR32和CYR33菌系在近等基因和SSR分子标记中发生了不同程度的毒性和基因型分化。

To understand the characteristics of virulence and genotypic diversity of Chinese races CYR32 and CYR33, 29 isolates of CYR32 and 39 isolates of CYR33 were selected randomly from 11 regions in China. Isolate virulence was assessed by using near-isogenic lines and assistant differential hosts, and genotypes were analyzed by 15 pairs of simple sequence repeat（SSR） markers. Virulence and molecular data were clustered separately. The results showed that each of CYR32 and CYR33 had17 virulent phenotypes. The majority of CYR32 and CYR33 isolates showed differentiation in resistance genes Yr2, Yr17, Yr27, Yr32, Yr43, Yr Sp, Yr Exp2, Yr28 and Yr V23, and the virulence diversity index of CYR32 and CYR33 were 0.089 and 0.097, respectively. The average of Shannon information index of CYR32 and CYR33 were 0.44 and 0.45, respectively. At 0.93 similarity coefficient level,CYR32 and CYR33 were divided into five and eight virulence groups, while molecular data of CYR32 and CYR33 revealed ten and 16 genotype groups with a similarity coefficient of 0.84. The results showed that races CYR32 and CYR33 with the same virulence characteristics to Chinese differential setcould be further separated with the aid of near-isogenic differential lines and genetic markers.