三倍体芒草自然杂交后代数量性状遗传多样性研究

以三倍体芒草奇岗的自然杂交后代为研究对象,对后代群体的16个数量性状分别进行变异分析、主成分分析和聚类分析。研究结果表明:(1)该杂交群体的变异系数在14.41%~151.85%之间,平均变异系数为51.22%,说明杂交后代变异广泛。(2)主成分分析结果表明,前4个主成分反映原变量的80.206%的信息。第1主成分贡献率为48.74%,较大载荷性状有分蘖数、丛径、基部周长、单株鲜重和单株干重;第2主成分贡献率为16.313%,较大载荷性状有外径、内径、单茎干重、单茎鲜重和含水量;第3主成分贡献率为7.775%,仅有腋芽数一个较大载荷性状;第4主成分贡献率为7.378%,仅叶片数一个较大载荷。(3)聚类分析结果表明,将66份奇岗自然杂交后代和6份母本奇岗种质分为4大类。第Ⅰ类材料因本身各性状不足,产量很低,不适合筛选高产种质;第Ⅱ类材料各性状变异系数普遍较小,性状稳定,适合作为育种的备选类群;第Ⅲ类材料因枯黄较少,更适合做发酵类能源草或青贮牧草;第Ⅳ类材料生物产量因子及其产量构成因子都明显优于母本,是较好的育种材料。以上研究结果对筛选芒属植物优良种质、创新芒属植物种质资源有积极意义,并为芒属植物多倍体育种提供理论依据和材料基础。

Study on Genetic Diversity of Quantitative Traits in the natural hybrid progeny of Triploid Miscanthus

In the present work,16 quantitative traits of natural triploid hybrid Miscanthus × giganteus J.M.Greef & Deuter were analyzed using the method of variation analysis,principal component analysis and cluster analysis.The results showed that:(1) Their variation coefficients ranged from 14.41％ to 151.85％ with the means of 51.22％,which indicated that the variation of crossbreed was wide.(2) The principal component analysis results showed that the first four principal components could reflect 80.206％ of the original variable information.The contribution rate of the first principal component was 48.74％,which was mainly contributed by the traits of tiller number per plant,cluster diameter,transect circumference,fresh weight per plant,and dry weight per plant;the second principal component contribution rate was 16.313％,which was mainly contributed by the traits of outside diameter,inside diameter,dry weight per stem,fresh weight per stem and moisture content;the third and fourth principal component contribution rate was 7.775％ and 7.378％,which was mainly composed by the trait of nodal bud number per stem,and the leaf number per stem respectively.(3) The cluster analysis results showed that 66 natural hybrid progeny and 6 female parent of Miscarnthus × giganteus J.M.Greef & Deuter germplasm were divided into 4 groups.The first group was composed by the material with low biomass yield.The materials in the second group were suitable for breeding because the variation coeffqcient of all their traits was generally small and stable.The materials in the third group were characterized to keep evergreen and then were identified to be suitable for biogas fermentation or silage grass.The traits of yield and yield components of the materials belonged to the fourth group were obviously superior to the female parent,indicating that they were good breeding materials.These above provided theoretical and material basis for screening and evaluating miscanthus germplasm and miscanthus breeding.