棉花黄萎病菌致病力分化与ISSR遗传变异分析

Pathogenicity Differentiation and ISSR Genetic Variation Analysis of Verticillium dahliae Isolates from Cotton in Shihezi,Xinjiang

从新疆北部石河子棉区分离纯化得到15个棉花黄萎病菌菌系,对其生物学培养特征、致病力、致病类型以及ISSR遗传变异进行了分析。菌株培养特征表明,在供试15个菌株中,菌丝型菌株最多,其次是菌核型,中间型最少,3种类型分别占60%,26.7%,13.3%。以2个棉花品种为寄主,室温人工接种鉴定菌株的致病力,结果表明,供试菌株存在明显的致病力分化,按照平均病情指数将供试菌株划分为强、中、弱3个类型,分别占73.3%,26.7%,0%。特异性引物(ND1/ND2和D1/D2)PCR检测结果显示,供试菌系中落叶型菌系有5个,占33.3%,非落叶型菌系有10个,占66.7%,其中落叶型菌株的平均致病力高于非落叶型。菌株ISSR指纹分析表明供试菌株间遗传变异较大,进一步分析发现,ISSR遗传分化与致病力具有一定的相关性。研究结果还发现,菌株XJ-1和XJ-6遗传相似系数在99%以上,但其致病力存在明显差异;同一病株上存在不同菌落形态和致病力的2个菌株XJ-8-1和XJ-8-2,但遗传相似系数在95%以上,这都充分表明了新疆石河子棉花黄萎病菌致病力分化与遗传变异关系的复杂性,为棉花黄萎病抗病育种以及综合防治提供了重要的理论参考。

Fifteen Verticillium dahliae isolates were recovered from cotton in Shihezi ,Northern Xinjiang .Cultu-ring characteristics ,pathogenicity ,pathogenicity types and ISSR genetic variation of fifteen isolates were researched . The study of culturing characteristics on PDA medium showed that the examined strains could be divided into fila -mentous type,sclerotia type and intermediate type,which accounted for 60%,26.7%,13.3%,respectively.The pathogenicity test of all strains on two cotton varieties based on artificial inoculating in chamber indicated that fifteen isolates had obvious pathogenicity differentiation .The tested isolates could be divided into strong pathogenic type , middle pathogenic type and weak pathogenic type based on average disease index of two cotton varieties .No strains were weak pathogenicity ,while the strong pathogenic strains and middle pathogenic strains occupied for 73.3%, 26.7%,respectively .According to the results of special PCR primers （ ND1/ND2 and D1/D2 ） , the defoliating and non-defoliating strains accounted for 33.3%,66.7%of the tested isolates,respectively.And the average virulence of defoliating strains was stronger than non-defoliating strains .The genetic variation of fifteen Verticillium dahliae isolates was large ,but related to pathogenicity from ISSR fingerprint analysis .The results also showed the genetic similar coefficient of two tested strains XJ-1 and XJ-6 was high with above 99%,but the pathogenicity was signifi-cant difference and two strains XJ-8-1and XJ-8-2 with different culturing characteristics and pathogeniciy recovered Fifteen Verticillium dahliae isolates were recovered from cotton in Shihezi ,Northern Xinjiang .Cultu-ring characteristics ,pathogenicity ,pathogenicity types and ISSR genetic variation of fifteen isolates were researched . The study of culturing characteristics on PDA medium showed that the examined strains could be divided into fila -mentous type,sclerotia type and intermediate type,which accounted for 60%,26.7%,13.3%,respectively.The pathogenicity test of all strains on two cotton varieties based on artificial inoculating in chamber indicated that fifteen isolates had obvious pathogenicity differentiation .The tested isolates could be divided into strong pathogenic type , middle pathogenic type and weak pathogenic type based on average disease index of two cotton varieties .No strains were weak pathogenicity ,while the strong pathogenic strains and middle pathogenic strains occupied for 73.3%, 26.7%,respectively .According to the results of special PCR primers （ ND1/ND2 and D1/D2 ） , the defoliating and non-defoliating strains accounted for 33.3%,66.7%of the tested isolates,respectively.And the average virulence of defoliating strains was stronger than non-defoliating strains .The genetic variation of fifteen Verticillium dahliae isolates was large ,but related to pathogenicity from ISSR fingerprint analysis .The results also showed the genetic similar coefficient of two tested strains XJ-1 and XJ-6 was high with above 99%,but the pathogenicity was signifi-cant difference and two strains XJ-8-1and XJ-8-2 with different culturing characteristics and pathogeniciy recovered from the same diseased cotton were high similar with above 95%,indicating pathogenicity differentiation and genetic variation of Verticillium dahliae from Shihezi was complex .The study results would provide reference in order to breed cultivars and integrated control .