中文摘要：

【目的】运用ISSR-PCR技术揭示中国河南和河北省冬小麦区6个地理群体小麦茎基腐病优势病原菌假禾谷镰孢（Fusarium pseudograminearum）的遗传多样性。【方法】利用筛选的17个ISSR引物对从河南和河北冬小麦区收集的166株假禾谷镰孢菌株进行扩增。根据群体扩增的结果,用POPGENE version l.32软件计算各项遗传多样性参数。根据不同地理群体的遗传相似系数,用NTSYSpc version 2.11软件进行群体聚类分析。【结果】从97个ISSR引物中筛选出了17个多态性较好的引物,用这17个引物对河南和河北冬小麦区的166株假禾谷镰孢菌株进行扩增,共扩增出234个DNA片段,其中多态性位点为218个,占总扩增片段的93.16%。平均每个引物可以扩增出13.76个条带,扩增产物大小在150—2 500 bp。POPGENE分析表明,6个地理群体的多态位点数在58—208,平均为124;多态位点百分率在24.79%—88.89%,平均为52.92%;有效等位基因数在1.1548—1.3293,平均为1.2584。遗传多样性分析表明,在地理种群水平上,Nei’s基因多样性指数在0.0897—0.2069,平均为0.1548;Shannon’s信息指数在0.1337—0.3257,平均为0.2368,这表明不同地理群体间存在一定的遗传变异。河南北部地区的Shannon’s信息指数和Nei’s基因多样性指数最高,表明该地区假禾谷镰孢菌株之间的遗传多样性最丰富。河南南部地区的Shannon’s信息指数和Nei’s基因多样性指数最低,表明该地区假禾谷镰孢菌株之间的遗传多样性最低。遗传相似性分析证明,河南北部地区假禾谷镰孢种群和河南东部地区种群最近,河南南部地区假禾谷镰孢种群和河南东部地区种群最远。6个地理群体间的遗传分化系数Gst为0.1571,群体内为0.8429,群体内多样性大于群体间的多样性。6个地理群体间的基因流Nm为2.6819,说明不同地理群体假禾谷镰孢菌株间存在较大的基因流动。6个地理群体总基因多样度Ht为0.1837,?

英文摘要：

【Objective】 Fusarium pseudograminearum is the dominant pathogen causing wheat crown rot. The objective of this study is to reveal the genetic diversity of F. pseudograminearum populations collected from Henan and Hebei winter wheat regions using inter-simple sequence repeat（ISSR） technology. 【Method】 F. pseudograminearum populations containing 166 isolates collected from Henan and Hebei winter wheat regions were amplified using 17 ISSR primers. Genetic diversity parameters were calculated by POPGENE version l.32 software. According to the genetic similarity coefficient of different geographical populations, the group clustering analysis was conducted using NTSYSpc version 2.11 software. 【Result】 Seventeen ISSR primers which could amplify more polymorphic loci were screened from 97 ISSR primers. The genetic diversity of 166 F. pseudograminearum isolates collected from Henan and Hebei winter wheat regions was analyzed with 17 primers. The amplification results showed that 234 fragments were amplified, and 218 fragments displayed polymorphic which accounted for 93.16% in the total amplified fragments. The average number of bands amplified per primer was 13.76 and the length of the amplified fragments ranged from 150 to 2 500 bp. The POPGENE analysis results showed that the number of polymorphic loci of 6 populations of F. pseudograminearum ranged from 58 to 208 with an average of 124. The percentage of polymorphic loci ranged from 24.79% to 88.89% with an average of 52.92%. The effective number of alleles ranged from 1.1548 to 1.3293 with an average of 1.2584. At geographical population level, Nei＇s gene diversity ranged from 0.0897 to 0.2069 with an average of 0.1548 and Shannon＇s information index varied from 0.1337 to 0.3257 with an average of 0.2368, indicating that there was a genetic variation between geographic populations of F. pseudograminearum. The Shannon＇s information index and Nei＇s gene diversity of Northern Henan were highest indicating that the isolates of F. pseudograminearum