重庆地区辣椒疫霉生理小种组成和群体遗传多样性分析  

PhysiologicaIl race and genetic diversity of Phytophthora capsici in Chongqing

作　　者：张世才[1] 张基林 段敏杰 杨小苗 黄启中[1] 黄任中[1] 李怡斐[1] 罗云米[1] ZHANG Shicai;ZHANG Jilin;DUAN Minjie;YANG Xiaomiao;HUANG Qizhong;HUANG Renzhong;LI Yifei;LUO Yunmi(Vegetable and Flower Research Institute,Chongqing Academy of Agricultural Sciences,Chongqing 401329,China;College of Life Science,Chongqing Normal University,Chongqing 401331,China)

机构地区：[1]重庆市农业科学院蔬菜花卉研究所,重庆401329 [2]重庆师范大学生命科学学院,重庆401331

出　　处：《植物病理学报》2024年第4期687-701,共15页Acta Phytopathologica Sinica

基　　金：国家特色蔬菜产业技术体系(CARS-24-A-04);川渝联合实施重点研发项目(cstc2021jscx-cylhX0002);重庆市人民政府与中国农业科学院农业科技创新战略合作项目(渝农发2022-164号)。

摘　　要：本研究采用平板对峙培养、鉴别寄主灌根接种和微卫星分子标记等方法,对2019和2020年采集自重庆市的66株辣椒疫霉(Phytophthora capsici)进行交配型、生理小种组成和群体遗传多样性分析。交配型检测结果显示A1交配型有13株,A2交配型有53株。生理小种鉴定结果显示42株P.capsici中有11株race1、28株race2、1株race3和2株race6(超级毒性小种)。利用6个已报道的微卫星分子标记位点对所有P.capsici菌株进行群体变异分析,共计获得59个不同的基因型;来自重庆地区11个P.capsici地理群体的有效等位基因数Ne为1.786~2.881,期望杂合度He为0.352~0.577,Shannon-Wiener指数H为1.242~2.079,多态标记百分率为83.33%~100%,群体之间的基因交流频繁(Nm=0.133~7.680),总群体的遗传分化处于中等水平(F_(ST)=0.113)。以上结果表明P.capsici在重庆各区县的遗传变异程度不同,总群体内杂合子过剩,具有丰富的遗传多样性。各地理群体的交配型组成、固定系数以及Hardy-Weinberg平衡和连锁不平衡检验提示重庆地区P.capsici可能同时存在无性和有性繁殖。AMOVA分析结果显示遗传变异主要来自群体内部。主成分分析(DAPC)表明重庆地区P.capsici菌株间存在明显差异,可划分为2个类群。Structure分析显示重庆地区P.capsici可能来自两个不同的祖先群体。上述有关重庆地区P.capsici有性生殖、生理小种组成和群体遗传结构等方面的研究结果为该地区辣椒疫病的防控奠定了基础。In this study,the mating types,physiological race composition,and genetic structures of 66 Phytophthora capsici isolates,collected from Chongqing during 2019-2020,were revealed by antagonistic culture,root-irrigation inoculation of differential hosts,and simple sequence repeats(SSR)marker-based analysis.The results showed that there were 53 P.capsici isolates of A2 mating type and 13 isolates of Al mating type;11 isolates of race 1,28 isolates of race 2,1 isolate of race 3,and 2 isolates of race 6.Genetic variation analysis of the P.capsici population,which consists of 11 different geographical sub-populations,was carried out by using six common SSR markers,and 59 different genotypes were obtained in total,with effective alleles of 1.786-2.881,expected heterozygosity of 0.352-0.577,Shannon-Wiener index of 1.242-2.079,and percentage for polymorphic markers of 83.33%-100%,and high levels of gene exchange occurring within subgroups(Nm=0.133-7.680)were indicated by medium population differentiation(F_(ST)=0.113).It was concluded that the degree of genetic variation of P.capsici populations in different regions of Chongqing was different,while the whole population had a surplus of heterozygotes,indicating a rich genetic diversity.The mating type proportion,fixation index,Hardy-Weinberg balance and linkage disequilibrium analysis for each geographical population showed that asexual and sexual reproduction may co-exist in P.capsici populations of Chongqing.Analysis of molecular variance(AMOVA)further showed that genetic variation mainly occurred within populations.Discriminant analysis of principal components(DAPC)showed that there were obvious differences and group division among P.capsici isolates from Chongqing,which could be divided into two groups.Structural analysis showed that P.capsici in Chongqing may come from two different ancestral groups.The results lay a basis for the control of Phytophthora blight of pepper plants.

关 键 词：辣椒疫霉 生理小种 遗传多样性 群体结构 

分 类 号：S436.418.1[农业科学—农业昆虫与害虫防治]