【作者】 马成涛；

【导师】 方炎明；

【作者基本信息】 南京林业大学 ， 植物学， 2011， 硕士

【摘要】 生物多样性是世界的自然财富,是人类赖以生存的基础,而遗传多样性又是生物多样性的基础,是遗传改良的源泉。红桤木是从北美引进的速生木本非豆科固氮树种,经济价值高,造林或栽培历史悠久,形成了优良的品系和相应的配套技术,适应性强,在特殊立地上可以造林,苗木生长量比国内同类树种或品种提高10%,红桤木成功引入中国,对造林及家具、制浆造纸等行业具有重要意义。因此,研究红桤木的遗传多样性具有重要意义。本文选取了在六合基地和下蜀林场两个栽培居群60个样本进行多样性研究。运用方差分析、UPGMA聚类和RAPD标记等方法,从表型和分子水平等系统地研究了红桤木群体内、群体间的变异,进而为红桤木育种和遗传改良奠定基础。1.通过对2个栽培居群60个样本进行表型特征分析,结果表明红桤木具有丰富的变异,各部位平均变异系数有明显差异,排序为：叶宽>叶长>叶脉>叶长宽比。2.四个性状表型分化系数变异幅度为0.27%～24.68%。群体间平均表型分化系数为7.97%,群体内平均表型分化系数为92.03%,群体内变异为其主要的变异来源。3.从45条随机引物中筛选出11条扩增谱带清晰且稳定的引物,用这些引物对60份种质进行扩增,扩增出位点81个,多态性位点81个,多态性比例为100%,具有较高的遗传多样性(Shannon多样性信息指数(Ⅰ)为0.509,Nei’s指数为0.3425),遗传分化Gst平均值为0.062,群体间基因多样性占总基因多样性的6.2%,群体内的基因多样性占总基因多样性的93.8%。红桤木的遗传多样性主要来自群体内部。4.基于红桤木表型和RAPD分子标记的聚类分析,本文认为：从种质保存的角度,六合居群的33、37、40、41、42、43、44、45、46、48、55、57、58和59号种质,下蜀居群的1、2、3、4、9、10、11、12、16、17、19、20、21、22、23、24、25、26和27号种质是需要保存的种质,用作育种材料。更多还原

【Abstract】 Bio-diversity is the natural wealth of the world and the foundation of human survial. The genetic diversity is the basis of bio-diversity and the source of genetic improvement. Alnus rubra is a fast-growing nitrogen-fixing species introduced from North America, high economic value, afforestation or cultivation has a long history,the formation of fine lines and corresponding supporting technology, adaptable, can be planted in special legislation on the ground, seedling growth compared with the similar species or varieties increased by 10%.The successful of Alnus rubra’s introduction is important for forestation, furniture and paper making. Therefore, the research of Alnus rubra’s genetic diversity has important meaning.In this paper,60 individual samples were collected from two cultivated populations located in LiuHe and XiaShu. From the phenotypic and molecular levels to study systematically the variation patterns within and among of Alnus rubra by using variance analysis, UPGMA clustering and RAPD markers, It will lay the foundation of Alnus rubra’s breeding and genetic improvement.1. Analysis of phenotypic characteristics of 60 samples from two cultivated populations showed that Alnus rubra had abundant variations. The average coefficients of variation were significantly different in different parts. From highest to lowest:leaf width> leaf length> leaf venation> leaf ratio.2. The variation range of four phenotypic differentiation coefficients was 0.27%～24.68%. The average coefficient of phenotypic differentiation among populations was 7.97%, while the average coefficient of phenotypic differentiation within groups was 92.03%, so the variation within groups was the main source of variation.3.45 random primers were selected from Invitrogen Corporation for the amplification reaction in the experiment.11 of which showed highly efficient amplification and were used for 60 germplasm in amplification test. The bands were clear and more polymorphic. All the bands were polymorphic in 81 loci and the ratio of polymorphic was 100%. Genetic diversity was abundant that judged from the average value of Shannon index (0.509), Nei index (0.3425). Gst index (0.062). Genetic diversity within populations possessed 93.8% and that among populations possessed 6.2% of the total. We can conclude that genetic diversity of Alnus rubra mainly from within populations.4. Based clustering analysis of phenotype and molecular makers of Alnus rubra, this paper suggested that the germplasm of No.33,37,40,41,42,43,44,45,46,48,55,57,58 and 59 from LiuHe population, as well as those of No 1,2,3,4,9,10,11,12,16,17,19,20,21,22,23, 24,25,26 and 27 from XiaShu population,were need to preserve as breeding material.,更多还原