小麦大面积种植品种与骨干亲本的遗传差异解析

Genetic Difference among Founder Parents and Widely Grown Cultivars Using SSR Markers in Wheat

为了解小麦大面积种植品种和育种骨干亲本的遗传差异特点,利用分布于小麦全基因组的428个SSR标记对4个大面积种植品种和4个骨干亲本进行了比较分析。结果表明,8个材料间的遗传距离变异范围为0.460～1.126,平均0.876,其中骨干亲本间的平均遗传距离（0.955）高于大面积种植品种（0.718）。骨干亲本中检测到的等位变异数较大面积种植品种高16.4%,前者的平均等位变异（2.90）也略高于后者（2.43）。从不同基因组和染色体来看,骨干亲本在A、B和D基因组上及19对染色体（除了2D和6D）的平均等位变异均高于大面积种植品种。以上分析表明骨干亲本的遗传异质性高于大面积种植品种。进一步比较二者的分子差异,发现骨干亲本中有518个特有等位变异（在大面积品种中没有出现）,其中Xwmc513和Xbarc59为骨干亲本共有位点,大面积品种中也检测到315个特有等位变异,其中Xp3029、Xwmc235、Xgwm518、Xgdm43、Xbarc146和Xcfd80为共有位点。前人研究表明骨干亲本的一些染色体区段传递给了大面积种植品种,在它们的形成中发挥了重要作用。本研究发现的特异位点可能是遗传研究中除了骨干亲本重要位点之外的一些需要重点关注的基因组区域,进一步研究有助于解析一个品种是被大面积推广利用或成为骨干亲本的形成原因。

To understand the genomic characteristics among founder parents and widely grown cultivars in wheat,eight representative accessions,consisting of four founder parents and four widely grown cultivars,were evalu ated using 428 SSR markers distributing on 21 chromosomes. The Nei＇s distances among the eight accessions based on SSR data varied from 0. 460 to 1. 126,with an average of 0. 876. The mean value of Nei＇s distances among the four founder parents was 0. 955,which was higher than that among four widely grown cultivars（ 0. 718）. The num ber of alleles amplified in the founder parents was over 16. 4% than that in the widely grown cultivars. The mean number of alleles per SSR locus in the founder parents was 2. 90,which was a little higher than that in the widely grown cultivars（ 2. 43）. On the other hand,we found that the mean number of alleles observed in the founder par ents were higher than that in the widely grown cultivars on A,B and D genomes,or 19 chromosomes with the excep tion of 2D and 6D. Such results indicated that the genetic diversity among founder parents was more abundant than that among widely grown cultivars. Furthermore,518 unique alleles,present in the founder parents and absent in al the widely grown cultivars,were observed. At Xwmc513 and Xbarc59 loci,the same alleles were detected in the four founder parents. On the contrary,315 unique alleles which were found in the widely grown cultivars but ab sent in all the founder parents,were observed. At six loci,Xpsp3029,Xwmc235,Xgwm518,Xgdm43,Xbarc146 and Xcfd80,the same alleles were found in the widely grown cultivars. Previous studies demonstrated that genomic regions contributed by a founder parent could be traced often in widely grown cultivars,which might play an important role for their production. The SSR loci detected in this study might be other important genomic regions,which would be helpful to understand the cause of formation for founder parent or widely grown cultivar in the fureher study.