【作者】 严茂粉；

【导师】 王克晶；

【作者基本信息】 中国农业科学院 ， 作物种质资源学， 2007， 硕士

【摘要】 野生大豆（Glycine soja）是栽培大豆（G．max）的野生祖先种，为栽培大豆的遗传育种和种质改良提供了重要的基因资源。北京地区是我国野生大豆分布区中部。近些年，北京地区经济迅速发展，人口急剧增加，一些因素破坏了野生大豆的生存环境，使宝贵的资源在逐渐流失。因此本文对北京地区的野生大豆进行考察和遗传多样性的研究，为考察、设立原位点保护、制定合理的取样保存方案、研究和利用提供理论依据。本文通过实地考察，收集北京地区野生大豆10个居群，每个居群30个单株（居群2为28个单株），共298个单株。分别从形态水平和分子水平上对北京野生大豆群体进行了遗传多样性分析。采集的种子进行田间种植，共调查了11个形态性状（7个数量性状和4个质量性状）；实验室内分析共采用了40对SSR引物，平均每个连锁群上2对引物。分析结果表明：1、质量性状多态相对单一；居群内个体间的数量性状值相差很大，居群间数量性状的平均差异大小有一定的地理分布性，但各性状差异表现不尽相同。性状变异系数大小顺序依次为：叶片长×宽＞单株产量＞地上部茎叶干重＞生长速率＞株高＞百粒重＞播种至开花天数。数量性状的多样性指数高于质量性状的多样性指数。Shannon指数计算表明北部山区指数最高，为1.42，其次是中-西部平原与山区，最低是东部山区，为1.19。1号居群的Shannon指数最高，9号居群多样性最低。通过聚类分析，把北京地区10个居群分为4组。2、利用40对SSR引物研究了北京地区天然野生大豆居群的遗传结构与遗传多样性。10个居群共检测到526个等位变异，平均等位基因数（A）为12.75个，平均有效等位基因数（A_e）为6.98，居群平均shannon指数（I）为0.658，平均期望杂合度（H_e）为0.369。平均基因分化程度(G_ST)为0.544，居群内遗传多样度(H_s为0.362，居群间遗传多样度(D_ST)为0.446。北京天然群体平均多基因位点杂合度（H_o）为1.3‰。本研究显示中-西部生态区居群比北部和东部山区居群有较高的遗传多样性。在地理上，环绕北京地区的太行山和燕山两大余脉区域野生大豆居群遗传分化表现出地理差异。我们看到一个可能是经过自然选择而形成的有抗旱潜力的居群在遗传上表现单一化。期待该居群提供耐旱基因利用。更多还原

【Abstract】 Wild soybean （Glycine soja） is commonly accepted as the ancestral species of the cultivated soybean （G. max）. As valuable genetic resources, wild soybean is an extraordinarily important gene pool for soybean breeding. In recent years, with the development of economy and the enhancement of population, some factors destroyed the survival environment of wild soybean. Now many valuable resources have been disappearing. Therefore, in order to provide scientific basis in making rational collecting, in-situ conservation, academic study and effective use of wild soybean resources, we collected natural populations of wild soybean growing in Beijing and analysed the genetic diversity.Ten natural populations of wild soybean in Beijing were collected. Each population had 30 individuals except population No.2 （28 individuals） and the total samples contained 298 individuals. We planted these individuals in the exprimental field and then investigated 11 morphologic characters including 4 qualitative and 7 quantitative traits. A set of 40 pairs of SSR primers with 2 pairs of primers per linkage group were used to analyse the genetic diversity. The results were as follows:1. The polymorphisms of the qualitative traits were simple; the variations （differences） in the quantitative traits were bigger within the populations and somewhat presented a region-dependent distribution geographically although some traits were different in distribution patterns. The CV of traits were showed as the follows: Leaf lengthxwidth>yield per plant>aboveground biomass>Growth rate >Plant height> 100-seed weight>Days from sowing to flowering. The Shannon-Weaver indexes of the quantitative traits were higher than those of the qualitative traits. The highest Shannon-Weaver index was 1.42 for the Northern mountainous area, while the lowest value of 1.19 for the Eastern mountainous one. The Shannon-Weaver index of population No.1 was the highest, while that of population No.9 was the lowest. Based on the morphological data, the 10 natural populations were clustered into 4 groups.2. In 10 natural populations, 526 alleles （bands） were detected in total. The average number of alleles per locus （A） and the effective number per locus （A_e） were 12.75 and 6.98, respectively. The mean values of expected heterozygosity and Shannon-Weaver index were 0.369 and 0.658, respectively. The natural populations showed a value of 0.446 for between-population genetic diversity （H_s） and 0.362 for within-population genetic diversity (D_ST). The coefficient of gene differentiation for the loci among the populations were estimated to be 0.544. The mean observed heterozygosity （H_o） of mulilocus was 1.29%. This study showed that the centre and western ecotopes had higher genetic diversity than the northern and eastern ecotopes and there were geographic genetic differentiation between the Taihang and the Yanshan mountains in natural populations of wild soybean in Beijing region. A drought-tolerance population presented extremely low genetic diversity, which seemed to have undergone and survived aridity and is expected in exploitation of tolerance gene（s） for crop breeding and applied ecology.更多还原