中文摘要：

从河南主要产棉区发病棉株中分离35个棉花黄萎病菌菌株。根据致病力测定结果,将河南黄萎病菌菌株和2个对照菌株划分为强致病力菌株、中等致病力菌株和弱致病力菌株3种类型,分别占24.3%、54.1%和21.6%。通过对其培养性状的测定发现,各地棉花黄萎病菌菌株的菌落生长速度和微菌核形成能力等培养性状上存在一定的差异,多数菌株为菌核型,占70.3%,少数为中间型和菌丝型,分别占21.6%和8.1%。不同培养类型的菌株致病力也不同,以菌丝型的菌株致病力最强,菌核型次之,中间型最弱。研究还发现,不同地区棉花黄萎病菌菌株间的致病力存在一定差异,同一地区的不同菌株间致病力也有一定差异。

英文摘要：

Total 35 strains of Verticillium dahliae were isolated from diseased cottons collected from main cotton production areas in Henan province. The Verticillium dahliae strains in Henan province could be divided into three pathogenic types： severe virulent type, intermediate virulent type and mild virulent type accounted for 24.3%, 54.1%, 21.6% respectively. The culture charac- teristics of these strains differed in growth rates of colony and the ability of microsclerotia formation. The sclerotium type was accounted for 70. 3%,and middle type and filament type with the proportion of 21. 6% and 8. 1% separately. The pathogenicity of strains with different cultural type differentiated,the filamentous type strains with severe virulence, the sclerotium type strains with intermediate virulence and the middle type strains with mild virulence. The pathogenicity of Verticillium dahliae in Henan showed differentiation among the strains from different regions in Henan,and the pathogenicity of the strains from the same place also had certain differences.