云南小麦条锈菌群体对18个抗条锈近等基因系的毒性分析

为监测云南省小麦条锈菌群体毒性及小麦抗条锈基因的有效性动态,2016年采用18个抗条锈近等基因系鉴别寄主对云南省9个州市的136个小麦条锈菌株进行毒性分析,并按八进制法对小种进行命名。结果表明,云南省小麦条锈菌群体毒性丰富,共鉴定出64个小种类型,其中居于前2位的小种是550273和550073,出现频率分别为28.68%和11.76%,是本年度优势小种;其它小种出现频率均在4.41%以下,为次要小种。条锈菌群体对Yr5、Yr10、Yr15、Yr32四个抗条锈基因的毒力频率均为0,对Yr24、Yr Tr1、Yr8、Yr17四个抗条锈基因的毒力频率在0.74%~11.76%之间,表明这8个基因是云南省当前有效的抗条锈基因;对Yr27的毒力频率为52.94%,对Yr1、Yr6、Yr7、Yr9、Yr43、Yr44、Yr SP、Yr Exp2、Yr Tye九个抗条锈基因的毒力频率为77.94%~91.91%,表明这10个抗条锈基因的抗性已减缓或丧失,说明这些基因在云南省已失效。

Virulence characterization of stripe rust pathogen Puccinia striiformis f. sp. tritici population to 18 near-isogenic lines resistant to wheat yellow rust in Yunnan Province

To characterize the virulence and race frequencies of the stripe rust pathogen, Puccinia striiformis f. sp. tritici(Pst) population and effectiveness of resistance genes to wheat stripe rust in Yunnan Province, a total of 136 isolates were collected from nine regions, and the virulence of all strains was identified using a set of 18 Yr near-isogenic lines, and races were named by octal code. The results showed that the Pst population in Yunnan was highly variable in races and virulence. Totally, 64 races were characterized and the top two most frequent races were 550273(28.68%) and 550073(11.76%), and the remaining races had frequencies less than 4.41%. No virulences was found for Yr5, Yr10, Yr15, and Yr32. The virulence frequencies to Yr24, YrTr1, Yr8, and Yr17 ranged from 0.74% to 11.76% . The eight genes are thought as effective genes in Yunnan at present. The virulence frequency to Yr27 was 52.94%; and those to Yr1, Yr6, Yr7, Yr9, Yr43, Yr44, YrSP, YrExp2, and YrTye ranged from 77.94% to 91.91%, indicating that the resistance of these ten genes to wheat yellow rust was declining and disappearing, and these genes were non-effective currently in Yunnan Province.