草地学报

›› 1998, Vol. 6 ›› Issue (2): 105-114.DOI: 10.11733/j.issn.1007-0435.1998.02.005

• 研究论文 • 上一篇    下一篇

苜蓿地方品种遗传多样性的研究──RAPD标记

李拥军1, 苏加楷2   

  1. 1. 全国畜牧兽医总站畜禽牧草种质资源保存利用中心, 北京, 100094;
    2. 中国农业科学院畜牧研究所, 北京, 100094
  • 出版日期:1998-05-15 发布日期:1998-05-15

Study on the Genetic Diversity of the Alfalfa Local Varieties(Medicago sativa L.)based on RAPD markers

Li Yongjun1, Su Jiakai2   

  1. 1. The Center of Preservation and Utilization of Germplasm Resources of Animal Husbandry and Forage Grass, The Center of National Animal Husbandry & Veterinary Service Beijing, 100094;
    2. Institute of Animal Science CARS, Beijing, 100094
  • Online:1998-05-15 Published:1998-05-15

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摘要： 利用RAPD技术对中国18个苜蓿地方品种和北美9个苜蓿基本种质来源的代表品种各取10个单株进行多态性分析。结果表明,苜蓿品种内和品种间均具有明显的多态性,如采用混合样分析则掩盖了品种内的多态性,而品种间的多态性则明显降低。7条引物共检测出52个位点,其中50个位点是多态的。品种间的差别是由该51个多态位点出现带谱的频率不同而体现的。中国18个地方苜蓿品种总的遗传变异水平与北美9个苜蓿品种很接近,品种内平均多态位点比例和基因多样性大于后者,表明中国苜蓿品种的杂合性较高,品种内的变异幅度较大。基因分化系数(GST)分析结果表明,苜蓿的遗传变异主要存在于品种内,这一特点与多年生苜蓿的繁育体系(异交)有关。中国苜蓿品种的GST小于北美9个苜蓿品种,表明中国苜蓿品种间的基因交流较强,遗传变异相对更多地存在于品种内。同时表明苜蓿品种的遗传结构不仅与其繁育体系(异交)有关,并与其地理分布和来源有直接关系。RAPD标记所揭示的多态位点比例和基因多样性均高于种子贮藏蛋白标记,这与基因表达的不同层次有关。

关键词: 苜蓿, 地方品种, RAPD, 遗传多样性

Abstract: Genetic diversity of the 18 alfalfa local varieties in China and the 9 alfalfa varieties representing the 9 alfalfa basic germplasm sources in North America were studied using RAPD markers.Resultsshowed that:Obvious polymorphisms within and among varieties can be revealed by amplifying individula DNA samples. Meanwhile, polymorphisms within varieties are concealed, and among varieties are obviously reduced,when using bulk samples.7 primers reveal total of 52 loci,and all the loci are scored as 1 forpresent and 0 for absent. Among the 52 loci,50 are polymorphic. Defference between varieties is reflected by the different frequencies on different loci. Total genetic diversity(HT)of the 18 alfalfa local varieties in China are close to, and polymorphic loci rate(P)and genetic diversity within varieties(HS)are higher than,that of the 9 alfalfa varieties in North America, indicating that the varieties in China are more heterozygous, and genetic variation within varieties are relatively larger. Analysis of gene differential coefficient(GST)indicating that genetic variation of Medicago sativa is mainly exits within varieties. This characteristic is related to the breeding system(out-breeing)of Medicago sativa.GST of the 18 alfalfa local varieties in China is smaller than that of the 9 alfalfa varieties in North America, indicating that more genecommunications occurred between the alfalfa local varieties in China, and variation within varieties takes up more of the total genetic variation. These results verify that the genetic structure of ch alfalfavarieties isalso related to their geographic distribution and sources. Polymorphisms revealed by RAPD markers arehigher than that of seed storage protein markers , indicating that polymorphism vary with different t levels of gene expression.

Key words: Alfalfa, Local varieties, RAPD, Genetic diversity