摘要： 从河北省22个主要产棉县市分离纯化得到67个棉花立枯病菌菌株,经鉴定均为立枯丝核菌(Rhizoctonia solani Kühn)。菌丝融合试验表明,其中的62个菌株属于2个菌丝融合群,即AG-4和AG-2,分别占测定菌株的91.04%和1.50%;另有5个菌株与标准菌株不融合,占7.46%,表明河北省棉田立枯丝核菌的优势菌系是AG-4融合群。通过选用麦芽蛋白胨(MPDA)培养基(Ⅱ)进行对峙培养,将AG-4融合群菌株划分为6个不同的营养亲和群,即AG-4-A、AG-4-B、AG-4-C、AG-4-D、AG-4-E和AG-4-F,分别占测定菌株的59.02%,6.56%,9.84%,1.64%,21.31%,1.64%。致病力测定结果表明,不同菌丝融合群及其各营养亲和群致病力不同,以AG-4-A对棉苗的致病力最强,其次是AG-2,均导致棉苗死亡;AG-4-E和AG-4-F虽然致病,但并不致死棉苗,各群相对致病力强弱顺序依次为:AG-4-A>AG-2>AG-4-B>AG-4-C>非融合类>AG-4-D>AG-4-E>AG-4-F。

关键词: 立枯丝核菌, 菌丝融合群, 营养亲和群, 致病力测定

Abstract: Sixty-seven strains of Rhizoctonia solani were isolated from diseased cotton seedlings sampled from 22 main counties of cotton production in Hebei province. They were divided into two anastomosis groups through hypha mating with standard strain. The frequency of AG-4 was 91. 04% of the tested strains,which indicated that AG-4 was the major anastomosis group of R. solani in Hebei province. While the frequency of AG-2 was 1. 50%.The other five strains belong to non-fusion strains,accounting for 7. 46% in frequency. 6 vegetative compatible groups of AG-4 strains were determined by their behaviors on MPDA (maltose peptone dextrose agar) II medium.Pathogenicity assays of the 67 strains were conducted on cotton seedlings under greenhouse condition. Results demonstrated that AG-4-A displayed the strongest pathogenicity,and AG-2 was the second,whereas AG-4-E and AG-4-F showed the mild pathogenicity and did not cause dead cotton seedling. The pathogenicity of different anastomosis groups and their vegetative compatibility groups as follows: AG-4-A > AG-2 > AG-4-B > AG-4-C > non-fusion > AG-4-D > AG-4-E > AG-4-F.

Key words: Rhizoctonia solani, Anastomosis group, Vegetative compatible group, Assay of pathogenicity

中图分类号: 

• S435.62