我国玉米大斑病菌生理小种组成变异研究

采用常规鉴别寄主鉴定技术,分析采自2005年和2006年我国10省份的100份玉米大斑病病菌分离物的致病性变异。鉴定结果表明,共鉴定出15个类型的生理小种,0、1、2、3、N、12、13、1N、23、2N、3N、12N、123N、123、23N;我国玉米大斑病菌的小种组成在继续变化之中,在全国范围内已无优势小种的存在;1、0号生理小种虽然是主要小种类群,但所占比例也仅有约20%,生理小种组成趋于多元化;北方地区小种的毒力组成较南方地区复杂,且毒力更强,不仅有能够克服单抗性基因的小种,而且有能够克服4个抗性基因几乎所有组合类型的小种。

Races of Exserohihun Turcicum, Causal Agent of Northern Leaf Blight in China

Using the differential hosts One hundred isolates of Exserohihun turcicum, collected from 10 provinces in 2005 and 2006, were identified in pathogenic variation to different Ht resistance gene. The results showed that 15 physiological races including 0, 1, 2, 3, N, 12, 13, 1N, 23, 2N, 3N, 12N, 123N, 123, 23N were found. In the state and there were not dominant races as well as in main production areas of maize. Race 1 and 0 were also the main races but its frequency was only about 20% respectively, and it means that the race component is in pluralistic. In north of China the virulence of the races is stronger than that in the south of China, those races not only can infect the maize with single Ht gene, but also infect that with multi gene of Ht.