【摘要】 选用山东省有代表性的棉黄萎菌１６个菌株（系）各配制成一定浓度的孢子悬浮液，于棉苗２～３叶期蘸根接种，观察发病的反应型。结果表明：各菌株致病力强弱差异明显，可分为致病力强的Ⅰ型（即与落叶型相似）、致病力中等的Ⅱ型和致病力弱的Ⅲ型，并发现山东省有落叶型菌系存在。更多还原

【Abstract】 Sixteen strains of Verticillium dahliae isolated from Shandong Province and one strain(VD-8)from BAU and two(T-9、SS-4)from USA were studied in the seedlings of cotton with root-dip methodin greenhouse. All strains were dlvidied into three types of pathogenicity. Type Ⅰ showed severe defoliat-ing virulance, Type Ⅱ was an intermediate type with indefoliating dead leaves.Type Ⅲ were character-ized by a mild wilt with yellow spots on leaves.更多还原