【作者】 刘振虎；

【导师】 卢欣石；

【作者基本信息】 北京林业大学 ， 森林培育， 2004， 博士

【摘要】 本研究采用形态学、等位酶及AFLP分子标记技术，以中国苜蓿40份材料为样本，以美国、法国和澳大利亚的34份材料作对照，首次从表型、蛋白质和DNA三个水平对中国苜蓿品种资源的遗传变异与其进化和分布之间的关系进行了分析，取得了中国苜蓿品种资源遗传多样性分布规律的初步结果。 针对8个形态学性状变异的研究发现，中国苜蓿种群遗传变异十分丰富，参试材料种群内的变异大于种群间的变异。在形态学性状中，第一真叶高度具有最高的变异水平，种群内的变异系数达26.40％，其余的性状中变异超过10％的还有叶长宽比指标，达14.26％。相关分析发现，除叶宽和单株分枝数两个指标以外，其余各性状之间都表现出显著的相关性。主成分分析表明，植株高度因素和叶长因素构成了第一主因子，在所有形态学变异来源中，这两个因素起着主导的作用。 通过对4种等位酶系统LAP、EST、PGM和MDH的淀粉凝胶电泳分析发现，在22份中外苜蓿品种(系)材料中共检测到9个基因位点和28个共显性等位基因。研究在遵循孟德尔遗传规律的基础上按照单体酶和二聚体酶在同源四倍体紫花苜蓿中的酶型规律对各酶谱进行了分析。结果表明，中国苜蓿种群等位酶分析平均多态位点比例为74.07％。在多态位点上的等位基因频率范围在0.788～0.003，平均每个位点上的等位基因数为2.73，明显高于外国对照种群(0.785～0.002和2.43)。 首次应用AFLP分子标记技术对我国北方苜蓿分布区12个省份的具有代表性的紫花苜蓿(Medicago sativa L．)种群40份材料进行了遗传多样性分析。结果表明，40个中国苜蓿种群的AFLP标记图谱显示了较高的多态性。从筛选出的4对AFLP引物组合(分别是E35／M50、E35／M49、E38／M62和E40／M47)中共得到到177条清晰的显带，其中97条呈多态性，平均每对引物扩增出44.3条带，多态性带的比例达54.8％。采用Nei的遗传相似系数和遗传距离矩阵得到的中国苜蓿种群间的遗传距离范围在0.548～0.802，聚类结果表明，起源以及分布区较近的品种(系)具有优先聚类的趋势。更多还原

【Abstract】 The relationship between genetic variance and evolution and distributing of alfalfa germplasm in morphological, protein and DNA levels are studied by morphological, allozymes and AFLP technics using 40 accessions which come from main growth areas in northern China as objects and 34 accessions including American, Australian and France materials as checks. A primary result was obtained in the field of alfalfa genetic diversity in China.Abundant genetic variance is found in alfalfa germplasm of China through research on the morphologic traits. And the intra-variance is larger than the inter-variance of the alfalfa population of China. The trait with the largest variance is euphylla height (EH), whose coefficient variance (C.V) is 26.40%, and the coefficient variance (C.V) of the Ratio of leaf Length and leaf Width (L/W) is above 10%( 14.26%). Multi-comparison indicated that all the variance levels have significant correlation among the studying traits except leaf width and branch amount of individual plant (BAP). Main component analysis indicated that the height and leaf length made up of the first component, and they play a important roles in the total morphological variances.Through the starch gel electrophoresis of four different allozymes as LAP, EST, PGM and MDH, 9 locus and 28 co-dominant alleles were found in all 22 alfalfa accessions. According to the genetic law of the zymogram of mornomeric and diameric enzyme in the quadploid plant the allele frequencies in polymorphic loci were statistically analyzed. The allozyme data indicated that in all examined loci, the polymorphic loci percentage is 74.07%. The range of allele frequencies is 0.788~0.003, and the average allele number in polymorphic loci is 2.73, which is much higher than the foreign check cultivars (0.785~ 0.002 and 2.43) .For the first time the genetic diversity of 40 alfalfa (Medicago sativa L.) populations distributing around 12 province of China is analyzed using AFLP technique. The result showed that the polymorphism is in a high level in China alfalfa populations. We have selected total 177 bands by 4 pairs of primer combinations, as E35/M5O, E35/M49, E38/M62 and E40/M47, which 97 are polymorphism bands. The average of each pair of primer combinations has amplified 44.3 bands. The percentage of polymorphism band is 54.8%. The genetic distance range of alfalfa population of China is 0.548-0.802. Cluster analysis showed that populations with a close origin and similar distributing area could get a prior clustering.更多还原