22份野生披碱草属种质农艺性状遗传多样性分析及综合评价

Genetic Diversity Analysis and Comprehensive Evaluation of Agronomic Traits of 22 Wild Elymus Germplasms

为客观评价披碱草属种质资源农艺性状的遗传多样性,对22份野外采集的披碱草属种质资源的15个农艺性状进行形态多样性指数分析,并对其进行相关性分析、聚类分析和主成分分析。结果表明,株高的遗传多样性指数最高(H′=1.8946);小花数变异系数(CV)最大(29.94%);株高与茎粗、旗叶长、旗叶宽、倒2叶长、倒2叶宽呈极显著正相关(p<0.01);聚类分析将22份披碱草属野生种质资源分为四个类群,第Ⅰ类群包括9份种质,具有穗长和花序长最短、花序小穗数最少等特点;第Ⅱ类群包括4份种质,具有最长茎长(包括花序)最长、花序小穗数和小花数最多,千粒重最重的特点,可作为选育种子产量高的品种的优良亲本;第Ⅲ类群包括5份披碱草属种质,具有植株矮小、茎秆较细、叶片细小的特点;第Ⅳ类群包括4份披碱草属种质,具有植株高大、茎秆较粗、叶片宽大的特点,可作为选育饲草产量较高抗倒伏品种的优良亲本。主成分分析将15个数量性状指标集中在累积贡献率达83.16%的5个主成分中,第一主成分与披碱草饲草产量密切相关;第二主成分载荷最高的是穗长和花序长;第三主成分载荷最高的是种子长和茎节数;第四主成分载荷最高的是种子宽;第五主成分载荷最高的是小花数。综上所述,22份野生披碱草属种质资源的遗传多样性丰富,E 22和E 08种质具有植株高大、茎秆粗壮、叶片宽大等优良特点,可以作为亲本用于改良当地披碱草属牧草品种。

In order to objectively evaluate the genetic diversity of agronomic traits in Elymus germplasms,the morphological diversity index of 15 agronomic traits from 22 field collected Elymus germplasms was analyzed,and the correlation analysis,cluster analysis and principal component analysis were also performed.The results showed that plant height had the highest genetic diversity index(H′=1.8946)and the maximum coefficient of variation of floret number(29.94%).Plant height was significantly positively correlated with stem diameter,flag leaf length,flag leaf width,length of penultimate leaf and width of penultimate leaf(p<0.01).Cluster analysis showed that the 22 wild Elymus germplasms were divided into four groups,and the group I consisted of 9 germplasms,which had the shortest panicle length and inflorescence length,and the least number of spikelets.GroupⅡcontained four germplasms,with the longest stem length(including inflorescences),the largest number of spikelets and florets in inflorescences,and the heaviest 1000-seed weight.It could be used as an excellent parent for breeding varieties with high seed yield.And,groupⅢincluded 5 Elymus germplasms,which were characterized by stunted plants,thin stalks and small leaves.GroupⅣconsisted of four Elymus germplasms,which had the characteristics of tall plants,thick stalks and wide leaves,and could be used as excellent parents for breeding varieties with high forage yield and lodging resistance.Principal component analysis(PCA)concentrated 15 quantitative traits into 5 principal components with a cumulative contribution rate of 83.16%,and the first principal component was closely related to the forage yield of Elymus,while the second principal component with the highest load was panicle length and inflorescence length.The highest load of the third principal component load was seed length and the number of stem nodes,and the fourth principal component with the highest load was seed width.Finally,the fifth principal component with highest load was the floret number.In conclusion,the genetic diversity of the 22 wild Elymus germplasms resources was rich.The germplasms of E 22 and E 08 had excellent characteristics including tall plants,stout stems and wide leaves,which could be used as parents to improve local Elymus germplasms.