大麦条纹病抗性鉴定及与SSR标记的关联分析

Barley Leaf Stripe Resistant Identification and Association Analysis with SSR Markers in Barley Germplasms

大麦条纹病是对大麦产量及品质影响最为严重的病害之一,为探明我国不同来源的大麦种质对条纹病的抗性差异并挖掘与大麦抗条纹病相关联的候选标记,本研究利用97个SSR标记对137份大麦品种进行遗传多样性及群体结构分析,并结合抗性鉴定结果进行关联分析。结果表明,人工接种大麦条纹病菌后共鉴定出18份免疫、27份高抗、28份中抗、42份中感和22份高感大麦材料;在97对SSR引物中挑选出85对多态性较好的引物,85对SSR标记共检测到651个等位变异,平均每个标记为7.57个;SSR标记的基因多样性指数变幅为0.0401~0.8646,平均值为0.5799;多态性信息含量变幅为0.0393~0.8498,平均值为0.5155,137份大麦材料的遗传距离范围为0.1021~0.4807,平均值为0.2774;聚类分析及群体遗传结构分析均将137份大麦种质分为4大类群;根据一般线性模型(GLM,general linear model)共获得7个与大麦抗条纹病显著关联的标记(P<0.05),解释率在5.80%~17.89%之间,其中标记EBmatc0039的解释率最高;标记EBmac77和MGB357与大麦条纹病抗性呈极显著相关(P<0.01),二者在一般线性模型中解释率分别为6.07%和9.60%。本研究结果可为大麦抗条纹病育种提供参考。

Barley leaf stripe is one of the most serious diseases affecting barley yield and quality.In order to determine the resistant differences of barley germplasm to Pyrenophora graminea and explore candidate markers associated with resistance to Pyrenophora graminea.In this study,we identified the genetic diversity and population structure of 137 barley germplasms by 97 SSR markers and combined them with the results of resistance identification for association analysis.The results showed that 18 accessions were identified to be immunity,27 highly resistant,28 resistant,42 susceptible,and 22 highly susceptible by artificial inoculation with Pyrenophora graminea strain QWC.A total of 651 alleles were detected in 85 primer pairs,with an average of 7.57 alleles.The genetic diversity index ranged from 0.0401 to 0.8646,with an average value of 0.5799.Polymorphism information content ranged from 0.0393 to 0.8498,and the average was 0.5155,the genetic distances ranged from 0.1021 to 0.4807,with an average of 0.2774.The 137 barley germplasms were divided into four subpopulations by Cluster analysis and population structure analysis.A total of seven markers significantly(P<0.05)were obtainted to be associated with barley resistance to Pyrenophora graminea based on the general linear model,with the explained rates ranging from 5.80%to 17.89%,EBmatc0039 had the highest explained rate.EBmac77 and MGB357 were significantly associated with resistance to barley leaf stripe(P<0.01),the two markers'rate of phenotypic variation explained were 6.07%and 9.60%in General Linear Model.The results of this study can provide reference for barley resistance to Pyrenophora graminea breeding.