江苏省大丽轮枝菌的培养、遗传及致病特性分析

由大丽轮枝菌引起的黄萎病是我国棉花和茄子的主要病害之一,对棉花和茄子的生产造成巨大损失。为了研究大丽轮枝菌的群体遗传变异以及对棉花和茄子的交互致病性,本文对分离自江苏省的63个棉花黄萎菌和10个茄子黄萎菌进行了培养、遗传和致病特性分析。根据菌株在PDA培养基上生长时形成微菌核的多少来划分培养类型,结果菌核型占83.6%,成为主要的培养类型。用PCR技术检测菌株的致病类型、交配型以及是否具有无毒基因Ave1,结果落叶型菌株占86.3%,为优势种群,但是10株茄子黄萎菌100%都是非落叶型菌株;供试的所有江苏菌株交配型都是MAT1-2型,并且都没有无毒基因Ave1。选择江苏省的6个棉花黄萎菌和4个茄子黄萎菌在室内苗期接种棉花和茄子,进行交互致病性测定,结果这10个菌株都可以侵染棉花和茄子,而且来源于不同寄主作物的菌系之间致病力分化明显,表现在不同菌株对同一寄主的致病力不同,同一菌株对不同寄主的致病力也不同。研究结果为深入研究大丽轮枝菌群体遗传结构和制定黄萎病防治措施提供了理论支持。

Cultural,genetic and phytopathogenic characterizations of a Verticillium dahliae population from Jiangsu province

Verticillium wilt caused by Verticillium dahlia is one of the most important diseases on cotton and eggplants in China, which causes a significant reduction in yield of both crops. In order to reveal the population genetic variation and the cross-pathogenicity between V. dahliae isolates collected from cotton and eggplants , a V. dahliae population of 63 isolates from cotton and 10 isolates from eggplants in Jiangsu province was characte-rized in terms of the cultural morphology, genetic and phytopathogenic characterizations. According to the quantity of microsclerotia of the colonial morphology on PDA, the isolates were divided into three cultural types and the sclerotia type was the main group accounted for 83.6%. The pathotype, mating type and containing avirulence gene Ave1 were analyzed by PCR. The results showed that the defoliating pathotype was the dominant group accounted for 86.3%, but 100% of 10 isolates from eggplants in Jiangsu province were genotyped as nondefoliating. All of isolates from Jiangsu province were genotyped as MAT1-2, and there was no avirulence gene Ave1 in their genomes. The cross-pathogenicity of 6 isolates from cotton and 4 isolates from eggplants was determined by artificial inoculation on seedlings of cotton and eggplant. All 10 isolates could infect both hosts, and the pathogenicity varied not only among the different isolates to the same host but also on different hosts with the same isolate. These results will lay foundations for in-depth study of the genetic population structure of V. dahlia and for development of the disease control measures.