111份多棱大麦种质主要农艺性状的遗传多样性

Analysis of the Genetic Diversity of the Main Agronomic Traits of 111 Multi-rowed Barley Germplasm Accessions

为客观评价多棱大麦种质资源主要农艺性状的遗传多样性,指导大麦亲本选配,以取自国内外不同生态区的111份多棱大麦种质为材料,考察7个主要农艺性状,通过变异系数、遗传多样性指数、主成分分析和聚类分析对供试材料的遗传多样性进行综合评价。结果显示:1)各性状的变异系数差别明显,变幅为13.7%~37.8%,其中单株粒质量(变幅37.8%)、单株粒数(变幅35.2%)和单株穗数(变幅33.0%)变异较大。2)各性状的遗传多样性指数相近,其中单株穗数最小(指数1.994),穗下节间长最大(指数2.085)。3)主成分分析结果显示,前3个主成分对变异的累计贡献率达80.000%,反映了多棱大麦的单株粒质量、株高和千粒质量特性。4)聚类分析将供试材料分为3大类群,类群Ⅰ高秆大穗,千粒质量高,单株穗数和单株粒数低,以地方品种居多;类群Ⅱ矮秆穗小,千粒质量低,国外品种占半数以上;类群Ⅲ株高适中,单株穗数、单株粒数和千粒质量高,以育成品种为主。说明基于农艺性状对大麦种质遗传多样性评价简单可行。结合主成分和聚类分析指导亲本选配,有助于更快培育出符合育种目标的大麦新品种。

The current research was aimed to evaluate the genetic diversity of the main agronomic traits of multi-rowed barley germplasm,thus providing directions for parental combination in breeding.Seven agronomic traits were compared among 111 barley accessions from home and abroad to evaluate their genetic diversity based on coefficient of variation,genetic diversity index,and principal component and cluster analyses.Results were as follows.First,variation coefficients of different traits varied significantly and ranged from 13.7%to 37.8%,among which larger variation coefficients were recorded with the traits of grain weight per plant(37.8%),grain number per plant(35.2%),and spike number per plant(33.0%).Second,these traits had similar genetic diversity indexes,with the minimum value for spike number per plant(1.994)and maximum value for internode length below spike(2.085).Third,principal component analysis revealed that the top three principal components accounted for 80.000%of the variations,implying the importance of grain weight per plant,plant height,and thousand kernel weight of multi-rowed barley.Fourth,based on the cluster analysis,the 111 barley accessions were classified into three groups.Group 1 was characterized by higher plant height,bigger spike,greater thousand kernel weight,and lower numbers of spike and grain per plant,which mainly comprised landraces.Group 2 had the traits of lower plant height and thousand kernel weight,of which the majority were foreign varieties.Group 3 was characterized by medium plant height,higher numbers of spike and grain per plant,and greater thousand kernel weight,which mainly consisted of bred cultivars.These results suggest that it is simple and feasible to evaluate the genetic diversity of barley germplasm based on agronomic traits.The combination of principal component analysis with cluster analysis can guide the selection of parents,which will facilitate the breeding of new barley varieties with desirable agronomic traits.