玉米穗腐病致病禾谷镰孢复合种的遗传多样性、致病力与毒素化学型分析  

The Genetic Diversity, Pathogenicity, and Toxigenic Chemotypes ofFusarium graminearum Species Complex Causing Maize Ear Rot

作　　者：王宝宝 郭成[2] 孙素丽[1] 夏玉生 朱振东[1] 段灿星[1] WANG BaoBao;GUO Cheng;SUN SuLi;XIA YuSheng;ZHU ZhenDong;DUAN CanXing(Institute of Crop Sciences/National Key Facility of Crop Gene Resources and Genetic Improvement,Chinese Academy of Agricultural Sciences,Beijing 100081;Institute of Plant Protection,Gansu Academy of Agricultural Sciences,Lanzhou 730070)

机构地区：[1]中国农业科学院作物科学研究所/国家农作物基因资源与基因改良重大科学工程,北京100081 [2]甘肃省农业科学院植物保护研究所,兰州730070

出　　处：《中国农业科学》2020年第23期4777-4790,共14页Scientia Agricultura Sinica

基　　金：国家重点研发计划(2016YFD0100103);农作物种质资源保护与利用专项(2020NWB036-12);中国农业科学院农业科技创新工程。

摘　　要：【目的】明确中国玉米穗腐病致病禾谷镰孢复合种(Fusarium graminearum species complex,FGSC)的菌群遗传结构、致病力、毒素化学型及其相互关系,为玉米镰孢穗腐病防控提供参考信息。【方法】从中国玉米主产区采集玉米穗腐病样本,经单孢分离鉴定,选取代表性的禾谷镰孢复合种,利用22对SSR和10对VNTR引物,使用Popgen32、NTsys2.1、STRUCTURE2.3.4群体遗传学研究软件进行数据分析,结合TEF-1α、β-tubulin和RPB2基因测序构建系统发育树,分析7个地理区域禾谷镰孢复合种的遗传多样性,采用花丝通道注射接种法测定各镰孢菌的致病力,利用产毒基因特异性引物进行毒素化学型的检测。【结果】在禾谷镰孢复合种中共检测到等位位点数48个,多态性位点数39个,多态性条带比率为81.25%,每对引物扩增出多态性条带2—4条;禾谷镰孢复合种7个地理群体平均Shannon’s信息指数和Nei’s遗传多样性指数分别为0.41和0.29,7个地理区域遗传相似度集中在0.6677—0.8797,遗传距离为0.1282—0.4039,表明菌群间具有较丰富的遗传多样性。依据Nei’s遗传距离对7个地理种群进行UPGMA聚类分析,可划分为3个类群;STRUCTURE2.3.4群体结构分析表明,禾谷镰孢复合种菌群被分为2个大类群最合适,西北地区绝大部分属于类群A,华中地区和华南地区菌株均属于类群B,东北地区50%以上菌株属于类群B。TEF-1α、β-tubulin和RPB2基因序列分析表明禾谷镰孢复合种由禾谷镰孢(F.graminearum)、亚洲镰孢(F.asiaticum)、布氏镰孢(F.boothii)和南方镰孢(F.meridionale)构成,上述镰孢菌中存在142个单核苷酸多态性位点(SNP),通过这些差异序列构建的聚类图能清楚显示出各个种内与种间的遗传分化情况,各镰孢种内遗传多样性十分丰富。禾谷镰孢致病力最强,平均发病面积百分比为20.79%;亚洲镰孢、布氏镰孢和南方镰孢的平均发病面积百分比分别为15.79%、11.77【Objective】The objective of this study is to clarify the genetic structure,pathogenicity,toxigenic chemotypes,and their relationship of Fusarium graminearum species complex(FGSC)causing maize ear rot in China,and to provide reference information for prevention and control of Fusarium ear rot of maize.【Method】The samples were collected from the main maize producing areas in China.Twenty-two pairs of SSR and 10 pairs of VNTR primers,along with TEF-1α,β-tubulin and RPB2 gene sequences were used for genetic diversity and Popgen32,NTsys2.1,and STRUCTURE2.3.4 software were used to analyze the data and construct the phylogenetic tree.The pathogenicity of FGSC was determined using the silk channel injection inoculation method,and the specific primers were used to detect the toxigenic chemotypes【.Result】A total of 48 alleles were detected by SSR and VNTR primers,39 polymorphic sites were found,with a polymorphic band ratio of 81.25%among 45 strains,the polymorphic bands ranged from 2 to 4.The average Shannon’s information index and Nei’s genetic diversity index of the 7 FGSC geographic populations were 0.41 and 0.29,respectively,the genetic similarity in 7 regions was 0.6677-0.8797,and the genetic distance was 0.1282-0.4039,indicating that there existed rich genetic diversity among the flora.Based on the Nei’s genetic distance,7 FGSC geographical populations were divided into 3 groups by UPGMA clustering.The population structure of FGSC stains could be divided into two different groups by STRUCTURE2.3.4.Most of the strains from Northwest China belonged to group A,those in Central China and South China belonged to group B,and more than 50%of the strains in Northeast China belonged to group B.Based on the sequences of TEF-1α,β-tubulin and RPB2,FGSC was composed of F.graminearum,F.asiaticum,F.boothii,and F.meridionale.There were 142 single nucleotide polymorphisms(SNPs)among these Fusarium strains.The dendrogram constructed by these differential sequences could clearly show the genetic differentiation w

关 键 词：玉米穗腐病 禾谷镰孢复合种 遗传多样性 毒素化学型 致病力 

分 类 号：S435.131.4[农业科学—农业昆虫与害虫防治]