四川小麦品种的遗传多样性及其对条锈病和白粉病的抗性

小麦条锈病和白粉病是四川小麦生产中的两大主要病害。为系统掌握四川小麦品种的遗传差异性及抗病性水平,以大田样品和近10年审定品种为试验材料,利用SSR分子标记对其进行遗传多样性分析,并对其成株期条锈病和白粉病抗性进行了鉴定。结果显示,115份大田样品和33个审定品种构成的总群体共扩增出38条多态性带,遗传相似系数变化范围为0.62~1。大田样品的观察等位基因数、有效等位基因数、基因多样性指数、信息指数、多态性位点数和多态位点百分率分别为1.868 4、1.422 8、0.253 0、0.386 7、33和86.8%,各项参数值均高于审定品种。聚类结果显示,多数审定品种与大田样品同源且出现于多个采样地点。抗性监测结果表明,四川省生产上大面积种植的小麦品种抗条锈性丧失明显,对白粉病的抗性丧失不明显。

Genetic Diversity and Resistance to Stripe Rust and Powdery Mildew of Wheat Varieties in Sichuan Province

Stripe rust and powdery mildew are two of the most destructive diseases of wheat in Sichuan province.For the sake of monitoring genetic diversity and resistance breakdown in wheat against the stripe rust and powdery mildew,33 registered varieties were used,and field samples were collected respectively from 615 and 577 plots located at different regions of Sichuan from 2009 to 2011.The results of SSR analysis of 115 field samples and 33 registered varieties showed 38 polymorphic fragments and the genetic similarity coefficients among the tested samples and varieties were 0.6-1.The observed number of alleles,effective number of alleles,Nei's gene diversity index,Shannon's information index,number of polymorphic loci,and proportion of polymorphic loci of the 115 field samples were 1.868 4,1.422 8,0.253 0,0.386 7,33 and 86.8%,respectively,which were higher than those of 33 registered varieties.Phylogenic analysis indicated most of registered varieties and field samples were homologous,which were present in different regions.A significant breakdown of resistance to strip rust was monitored in field wheat samples in Sichuan province whereas the breakdown of resistance to powdery mildew was not obvious.