我国部分冬小麦品种(系)遗传多样性、群体结构和连锁不平衡分析  

Genetic Diversity, Population Structure, and Linkage Disequilibrium in Chinese Winter Wheat(Triticum aestivum L.)

作　　者：要燕杰 吴丹[1] 董剑[1] 赵万春[1] 陈良国[1] 石引刚[1] 高翔[1] 

机构地区：[1]西北农林科技大学农学院,杨凌712100

出　　处：《农业生物技术学报》2015年第7期863-875,共13页Journal of Agricultural Biotechnology

基　　金："十二五"农村领域国家科技计划课题(No.2011AA100501);国家小麦产业技术体系(No.CARS-3-2-47)

摘　　要：为了筛选与产量性状或品质性状显著关联的分子标记,本研究利用分布于不同染色体上的88对简单序列重复（simple sequence repeat,SSR）标记对91份我国冬小麦（Triticum aestivum L.）品种（系）进行了位点多态性分析、基于非加权平均法的聚类分析、基于数学模型的群体结构和连锁不平衡分析。结果表明,全部标记共检测到883个等位变异,平均等位变异是10.03;遗传多样性变化范围为0.160-0.932,平均值是0.703;多态性信息含量变化范围为0.148-0.929,平均值是0.667。这些结果显示目前我国冬小麦遗传多样性水平相对较低。其中B基因组的遗传多样性最高,D基因组最低。在多样性指数上,B基因组和D基因组差异显著（P〈0.05）。聚类分析将材料分成3大类,群体结构分析将材料分成4个亚群,类群划分结果与地理来源无明显关系,与系谱来源部分相关。聚类分析和群体结构分析相互补充和印证,使类群划分更加可靠。AMOVA分析显示,材料94%的遗传变异是由群体内不同个体间的差异造成的,6%的遗传变异与群体间的遗传分化有关。基因流数据显示不同的群体或亚群间存在着更频率的基因交流。基因组连锁不平衡衰减距离的＂基准线＂是r2=0.028 7,全基因组、A、B和D基因组连锁不平衡（linkage disequilibrium,LD）衰减距离分别是4.3、3.7、1.0和4.1 c M。B基因组LD衰减距离较短、衰减较快;A和D基因组LD衰减距离较长、衰减较慢。表明我国小麦LD衰减距离较高,采用全基因策略进行关联分析是可行的。评价我国小麦品种（系）的遗传多样性、群体结构和连锁不平衡,可为今后小麦杂交育种、分子标记辅助选择和关联分析提供参考和依据。In order to identify simple sequence repeat（SSR） markers which associated with yield or quality characters, this study was conducted to investigate polymorphism analysis of locis、cluster analysis based on unweight pair method using arithmetic averages、population structure analysis based on mathematic model and linkage disquilibrium analysis among 91 wheat（Triticum aestivum L.） cultivars and breeding lines using 88 wheat SSR markers distributed throughout the wheat genome. A total of 883 alleles were detected, with 2 to30 alleles per locus and a mean genetic richness of 10.03. The average genetic diversity index was 0.703, with a range from 0.160 to 0.932. The mean PIC value was 0.667, ranging from 0.148 to 0.929. These results indicated that the genetic diversity of the 91 Chinese winter wheat cultivars was low. Further analysis showedthat B genome had the highest genetic diversity and D genome had the lowest genetic diversity, significant differences were observed between these 2 genomes（P〈0.01）. The collection of winter wheats could be divided into 3 and 4 subgroups based on UPGMA（unweight pair method using arithmetic averages） and STRUCTURE analyses, respectively. The results of clustering had no obvious relationship with the geographic eco- type, but partly correlated to some extent with pedigrees. The results of clustering and population structure analyses could complement and confirm each other, making the results more reliable.Results of AMOVA（analysis of molecular variance） indicated that the majority genetic variation occurred in different individuals within a population. Furthermore, gene flow proved that there was some high frequency of gene intercommunication among different subpopulations. The baseline of linkage disequilibrium（LD）decay for genome was r2=0.028 7 and the mean LD decay distance of the whole genome was 4.3 c M, while the mean LD decay distance of A, B and D genome was 3.7, 1.0 and 4.1 c M, respectively. The LD decay distance and rate of B genome was shorter

关 键 词：小麦 简单序列重复(SSR)标记 遗传多样性 群体结构 连锁不平衡 

分 类 号：S435.122.1[农业科学—农业昆虫与害虫防治]