山东省和河北省小麦白粉菌毒性与遗传多样性分析

由Blumeria graminis f. sp. tritici引起的白粉病是危害我国小麦安全生产的重要病害之一。分析菌株毒性结构和抗病基因有效性对于利用寄主控制白粉病具有重要意义。本研究对2011年从山东和河北两省分离的41个菌株进行了毒性分析，并采用SSR标记对其遗传多样性进行了分析。测试菌株的毒性频率在0.35 (Bg40-2，山东烟台)至0.74 (Bg46-1，山东平度)之间。山东省菌株的平均毒性频率与河北省菌株没有显著差异。除别菌株外(例如Pm17)，山东省和河北省的菌株对大多数抗病基因的毒性差异不大。全部测试菌株对来自地方品种齿牙糙的Pm24基因都没有毒性。极少数菌株对Pm1c、Pm16、Pm20、PmH和Mlxbd的毒性频率低于0.1，在河北省邯郸市和黄骅市发现对Pm21基因具有毒性的菌株，但在山东省没有检测到对Pm21具有毒性的菌株。对Pm5e、 Pm6、 Pm12、 Pm13、 Pm17、 Pm40、 Pm2+6和Pm5+6的毒性频率在0.18~0.48之间，对Pm1a、 Pm3a、 Pm3c、P m3g、 Pm4a、 Pm4b、 Pm5a、 Pm7、 Pm8、 Pm19、 Pm33、 Pm43、 PmY39、 PmPS5A和Pm1+2+9的毒性频率超过0.6。遗传多样性分析可见，小麦白粉菌群体的遗传变异主要发生在群体内部，菌株间具有一定程度的基因交流。同一地点采集的不同单孢分离菌株有些可聚为一类，但有些不能聚为一类，说明其遗传基础可能存在差异。供试菌株对不同抗病基因的毒性多态性与DNA多态性之间不存在一一对应的关系。

Virulence and Genetic Diversity of Blumeria graminis f. sp. tritici Collected from Shandong and Hebei Provinces

Powdery mildew caused by Blumeria graminis f. sp. tritici (Bgt) is one of the most important diseases that damages wheat (Triticum aestivum L.) production in China. Analysis of virulence structure and effectiveness of resistance genes is important in the control of powdery mildew with host resistance. This study was conducted to test virulence structures of 41 isolates collected from Shandong and Hebei provinces in 2011. The genetic diversity of these isolates was also analyzed using SSR markers. The virulence frequencies of isolates tested ranged from 0.35 (Bg40-2, Yantai, Shandong) to 0.74 (Bg46-1, Pingdu, Shandong). The mean virulence frequency for the isolates from Shandong was not significantly different from that of the isolates from Hebei Province. Except for a few resistance genes such as Pm17, the virulence frequencies of isolates from Shandong and Hebei provinces on most resistance genes were not different. None of the isolates tested was virulent on Pm24 carried by the Chinese landrace Chiyacao. A few isolates were virulent to Pm1c, Pm16, Pm20, PmH, and Mlxbd. Two isolates from Handan and Huanghuang of Hebei Province were virulent on Pm21, but none of the isolates from Shandong Province was virulent on Pm21. The virulence frequencies for Pm5e, Pm6, Pm12, Pm13, Pm17, Pm40, Pm2+6, and Pm5+6 ranged from 0.18 to 0.48. Genes Pm1a, Pm3a, Pm3c, Pm3g, Pm4a, Pm4b, Pm4c, Pm5a, Pm7, Pm8, Pm19, Pm33, Pm43, PmY39, PmPS5A, and PmDR147 had the virulence frequencies over 0.6. Analysis of genetic diversity indicated that the genetic variation of Bgt isolates occurred within the population, and gene flow occurred among isolates. Although some single spore progenies from the same location were clustered together, some were not classified into the same cluster, indicating the variation in their genetic bases. The polymorphism of virulence patterns for various resistance genes was not necessarily consistent with the DNA polymorphism as revealed by SSR markers.