苜蓿DUS测试标准品种SSR分子标记指纹图谱的构建

苜蓿在育种过程中,由于其异花授粉特性和骨干亲本的集中使用,导致品种间的遗传差异日益缩小,品种之间通过形态学鉴定愈加困难。通过构建苜蓿DUS测试标准品种DNA指纹图谱数据库,可以实现苜蓿品种的快速、准确鉴定。本研究利用筛选得到的10个SSR标记对33个苜蓿DUS测试标准品种进行指纹图谱构建和遗传多样性分析。结果表明,10对SSR引物共扩增出69个等位基因,平均每个标记可产生6.9个等位基因;多态性比率(PPB)从25%到90%不等,平均值为56.7%;各SSR标记的多态信息含量(PIC)范围为0.56~0.87,平均值为0.75。利用不同引物间的组合能有效区分33个苜蓿 DUS标准品种,并为每份标准品种建立了唯一标识的指纹代码,为苜蓿品种的审定和保护以及遗传背景分析提供了技术依据。

Construction of SSR marker fingerprint database of standard alfalfa varieties utilizing DUS tests

Due to cross-pollinating characteristic and the excessive use of backbone materials during the alfalfa breeding,the genetic diversity of alfalfa varieties is declining,and the discrimination of different varieties through phenotypical characteristics is becoming more difficult.The construction of a DNA fingerprint database of standard alfalfa varieties through the distinctness,uniformity and stability (DUS) test can facilitate the identification of alfalfa varieties.In this study we analyzed the genetic diversity among 33 standard alfalfa varieties with a DUS test and the DNA fingerprint of each variety was constructed based on 10 SSR markers.The results showed that a total of 69 alleles were generated from the 10 SSR markers,with an average of 6.9 alleles per marker;the polymorphic ratio varied from 25％ to 90％,with an average of 56.7％.The polymorphic information content per SSR marker varied from 0.56～0.87,with an average of 0.75.The 33 varieties could be clearly distinguished by the 10 SSR markers.The DNA fingerprint of each variety was established providing a technical basis for the validation and conservation of alfalfa varieties and genetic background analysis.