2013年我国部分麦区小麦白粉菌群体对温度敏感性及其与毒性的关系

研究小麦白粉病菌群体对温度的敏感性及其与毒性的关系,可为气候变化背景下小麦白粉病的长期发生趋势预测和防治提供依据。本研究对2013年采自云南、四川、河南、北京和陕西五省(市)的小麦白粉菌标样进行分离纯化,获得90个单孢子堆分离物,采用小麦离体叶段法进行温度敏感性测定,并利用32个已知抗病基因品种(系)进行毒性测定,且对两者之间的相关性进行分析。结果表明,供试菌株ET_(50)分布于19.78℃~25.15℃,平均ET_(50)为23.22℃,其中73.34%的供试菌株ET_(50)值介于22℃到24℃之间,小于22℃的菌株占10%,大于24℃的菌株占16.67%。利用Popgen1.32软件对5个省(市)小麦白粉病菌群体的毒性进行多样性分析,结果表明五省市小麦白粉菌群体毒性水平上的多样性指数H值为0.237 0,其中四川群体毒性多样性水平最高,Nei’s基因多样性指数H值为0.221 2,河南群体最低,H值为0.197 5。小麦白粉菌群体对温度敏感性与毒性多样性相关性分析结果表明,ET_(50)与毒性多样性(H和I值)间存在显著的负相关。

Temperature sensitivity and its correlation with virulence of Blumeria graminis f. sp. tritici isolates in some wheat growing

In order to predict and control wheat powdery mildew ( Blumeria graminis f. sp. tritici) , we studied the sensitivity to temperature on pathogen isolates and the relationship between temperature-sensitivity and their virulences. In 2013, a total of 90 isolates were sampled from 5 provinces (cities)，including Yunnan, Sichuan, Beijing, Henan and Shaanxi. The isolates were tested on their sensitivity to temperature by using the detached leaf segment method and their virulences were determined by 32 wheat varieties or lines with known powdery mildew resistant genes. The results showed that the mean ET50 of tested isolates was 23.22℃. The highest and the lowest ET50 of the isolates were 25.15℃ and 19.78℃, respectively. The ET50 value of 73.34% of isolates ranged from 22.0℃ to 24.0℃, and 10% of isolates below 22℃, 16.67% of isolates above 24℃. The virulence gene diversity index of the 90 B. graminis f. sp. tritici isolates was 0.237 0. The highest index was recorded on isolates from Sichuan Province with H = 0.221 2 while the lowest index was recorded on isolates from Henan Province with H = 0.197 5. The results showed that there was a significant negative correlation between temperature-sensitivity and virulence diversity of B. graminis f. sp. tritici populations.