内蒙古30份冰草属种质资源表型性状遗传多样性分析

Genetic Diversity Analysis of Phenotypic Traits of 30 Agropyron Genus Germplasm Resources in Inner Mongolia

调查测定内蒙古30份冰草种质资源的22个表型性状,并进行相关分析、主成分分析及聚类分析,探究其表型性状的遗传多样性,为冰草遗传育种研究提供理论基础。结果表明:冰草种质资源质量性状和数量性状的遗传多样性指数变化范围分别为0.96~1.70和1.09~2.12,与质量性状相比,数量性状的变异更大。相关分析显示,株高与分蘖数、叶色与叶形态、叶鞘毛与叶片被毛等48个性状间呈极显著正相关(P<0.01);株高与小穗密度、叶片数与小穗密度、主茎节数与穗轴第一节间长、小穗密度与外稃长呈极显著负相关(P<0.01)。主成分分析显示,前10个主成分可反映表型性状70.26%的信息,采用主成分分析评价函数F和各性状指标进行线性回归构建了冰草种质资源综合评价函数。系统聚类分析将30份种质聚为3类,类群特征为矮株细茎密穗型的冰草种质占总样本量的86.67%。综上所述,冰草属植物种质资源存在丰富的形态变异,穗轴第一节间长、叶片数、分蘖数、外稃芒长4个性状的变异系数较大。

We investigated and measured 22 phenotypic traits of 30 Agropyron germplasm resources in Inner Mongolia,and conducted correlation analysis,principal component analysis,and cluster analysis to explore the genetic diversity of their phenotypic traits,providing a theoretical foundation for Agropyron genetic breeding.The results indicated that the genetic diversity indices for qualitative traits and quantitative traits ranged from 0.96 to 1.70 and 1.09 to 2.12 among populations,respectively,with greater variation observed in quantitative traits compared to qualitative traits.Correlation analysis revealed highly significant positive correlation(P<0.01)between 48 traits,such as plant height and tiller number,leaf color and leaf morphology,lamellar seta and leaf trichomes.Conversely,highly significant negative correlations(P<0.01)were observed between plant height and spikelet density,leaf number and spikelet density,main stem node number and the length of the first internode of the rachis,and spikelet density and the outer length.Principal component analysis indicated that the first 10 principal components could account for 70.26%of the information about phenotypic traits.We constructed a comprehensive evaluation function for Agropyron germplasm resources using linear regression with principal components analysis evaluation function F and various trait indicators.Cluster analysis grouped the 30 germplasm resources into three clusters,with the predominant cluster characterized by dwarf plants with slender stems and dense spikelet,representing 86.67%of the total samples.In summary,Agropyron germplasm resources exhibit rich morphological variation,with the largest variation coefficients observed in the traits of the length of the first internode of the rachis,leaf number,tiller number,and awn length.