采用微卫星(SSR)标记研究苜蓿品种鉴定初报

A Preliminary Study on Alfalfa Cultivar Identification Using SSR Markers

苜蓿(Medicago sativa L.)是异花授粉植物,自交则衰退,品种内个体间基因型杂合,因此品种鉴定的难度较大。本文以苜蓿地方品种、育成品种和引进品种为材料,采用微卫星分子标记研究和鉴定供试苜蓿品种。结果表明:采用变性聚丙烯酰胺凝胶电泳进行PCR产物分离可以避免非特异带的出现,降低了实验误差;在品种鉴定方面,AFca1位点片段大小为148 bp的等位基因在龙牧系列品种中出现的频率明显高于其它品种,可作为品种区别的依据;在其它品种之间或与杂花苜蓿品种之间,多数的SSR位点有基本相同的基因型和等位基因,品种间的区别主要在于等位基因频率的差异,而大部分品种之间频率的差异很小,不能作为鉴定的依据,即仅靠有限的SSR位点很难区别供试苜蓿品种;通过某些品种特有性状相连锁的分子标记与其它品种之间的差异作为鉴定的依据进行探索研究,或许能真正将某些苜蓿品种与其它品种区别开。

Being as a plant of cross-pollination, the cultivar identification of alfalfa （Medicago sativa L. ） is more difficult than other self-pollination plant because of the admixture genotypes within a cultivar. A preliminary study on alfalfa cultivar identification was conducted on native cultivars, bred cultivars, and cross cultivars using SSR markers. The results suggest that some nonspecific bands were avoided by using dena tured gels for the separating of PCR products; the gene frequency of 148bp band of AFcal loci was much higher in Longmu series cultivars than that in other alfalfa cultivars, by which Longmu cultivars were identified among alfalfa cultivars. However, the gene frequency differences could not be used for other cultivar identification, because the differences among other alfalfa cultivars were small. Thus, it was very difficult to identify all alfalfa cultivars by using limited SSR markers. Some alfalfa cultivars could be identified by using the molecular marker associated with a specific trait of the cultivar.