河南省玉米小斑病菌生理小种鉴定及致病力分化

Identification of Physiological Races and Pathogenicity Differentiation of Bipolaris maydis in Henan Province

2013年从河南省4个地区采集玉米小斑病标样,对分离出的140个玉米小斑病菌菌株进行了生理小种鉴定和群体结构分析。结果表明,河南省玉米小斑病菌有T、C、S、O等4种生理小种,但各小种在地区间的分布存在差异,其中,O小种是河南省各玉米产区小斑病菌的优势小种,且在豫南分布最广泛,其次是C小种和S小种,T小种的比例最小。O小种具有不同致病力,强致病力菌株的出现频率较弱致病力菌株高,强致病力菌株主要分布在豫南地区,弱致病力菌株主要分布在豫北地区。

Samples of corn leaf blight were collected from 4 locations in Henan province in 2013. Among them,140 strains of Bipolaria maydis were identified with the identification hosts. Population structure of Bipolaria maydis race was analyzed. The results showed that isolation frequencies of Race T,Race C,Race S and Race O were significantly different among locations. Isolation frequency of Race O was significant higher than those of the other races, indicating that Race O was the dominant race of B.maydis in the corn-growing area, most widely distributed in southern Henan province. Following races were Race C and Race S. The proportion of Race T was minimum. The pathogenicity of Race O was different. The isolation frequency of strongly pathogenic strains of Race O was more than that of the weak pathogenic strains. The strongly pathogenic strains were mainly distributed in the southern Henan, while the weak pathogenic strains were mainly distributed in the northern Henan.