不同来源大麦的SSR标记与连锁不平衡分析

SSR Markers and Linkage Unbalance Analysis of Different Barley Materials

为分析大麦种质材料遗传多样性并且为大麦基因型分析及育种组合选择提供依据,本研究利用品种间表现多态性的45个SSR标记对84份大麦材料进行分析,结果表明:(1)由45对SSR引物扫描鉴定出305个等位变异,平均每对引物扩增得到6.8个等位变异,同时45对引物的平均多态性信息含量为0.640 1;(2)根据遗传距离和聚类分析结果显示,本研究中84份大麦材料间的平均遗传距离约为0.614 2,表明由甘肃省农科院提供的84份大麦材料种质间遗传差异较大,亲缘关系相对较远;(3)群体遗传结构分析将84份种质材料分成6个亚群,与聚类分析结果较一致;(4)连锁不平衡结果显示,D'值范围主要集中在0和0.6之间,占到992个SSR标记位点成对组合的82.06%,表明这次选择的大麦种质材料内部基因间重组概率和突变概率都比较低;同时在分布于大麦7条染色体上的SSR分子标记检测中,发现了较高的LD水平(D'>0.5)主要分布于2H、4H、5H和6H上。由此可知,不管是自然变异还是人为选择,作物内部产生的遗传变异和连锁不平衡程度对研发高产和高抗逆作物的新品种起着至关重要的作用,所以通过大麦的SSR标记与连锁不平衡分析,可为今后的育种策略提供更有效和有针对性的理论方法。

In order to analyze the genetic diversity of barley germplasm materials and provide the basis for barley genotype analysis and breeding combination selection, this study used 45 SSR markers showing polymorphism among varieties to analyze 84 barley materials. The results showed that:(1) 305 alleles were identified from 45 pairs of SSR primers, with an average of 6.8 alleles amplified from each pair of primers, and the average polymorphism information content of 45 pairs of primers was 0.640 1.(2) According to the results of genetic distance and cluster analysis, the average genetic distance among the 84 barley materials in this study was about 0.614 2, indicating that the 84 barley materials provided by Gansu Academy of Agricultural Sciences had a large genetic difference and relatively distant genetic relationship.(3) The 84 germplasm materials were divided into 6 subgroups by genetic structure analysis, which was consistent with the results of cluster analysis.(4) The linkage imbalance results showed that D' values mainly ranged from 0 to 0.6, accounting for 82.06% of 992 SSR marker pairs, indicating that the intergene recombination probability and mutation probability were relatively low in the selected barley germplasm. At the same time, high LD levels(D'>0.5) were mainly distributed at 2H, 4H, 5H and 6H on seven barley chromosomes. It can be seen that whether natural variation or artificial selection, crop genetic variation generated inside and linkage disequilibrium degree to develop new varieties of high yield and high art crops plays an important role, so by SSR markers of barley and linkage disequilibrium analysis, for future breeding strategies to provide more effective and targeted theory method.