高粱株型表型性状精准鉴定及综合评价

Accurate Identification and Comprehensive Evaluation of Plant Architecture Related Traits in Sorghum

以高粱株型性状为研究对象,对株高、茎粗和叶片相关性状等9个指标进行精准鉴定,利用变异系数、相关性分析、聚类分析、主成分分析和隶属函数F值评价法对371份国内高粱种质资源进行精准鉴定与综合评价。结果表明:两年两点表型性状的平均变异系数范围为10.14%~39.37%,遗传多样性指数范围为1.94~2.14,种质资源变异种类丰富,节数、倒二叶角、倒三叶角和茎粗容易受到环境条件的影响。聚类分析将高粱种质资源分为三大类,第Ⅰ类为中秆平展型和中秆紧凑型植株,第Ⅱ类群为高秆平展型植株,第Ⅲ类群为矮秆紧凑型植株。通过主成分分析将9个性状分为4个主成分,第1主成分主要是茎粗、倒二叶宽、倒三叶宽和节数,贡献率为36.424%,第2主成分主要是株高、倒三叶长和倒二叶长,贡献率为24.786%,第3主成分主要是倒三叶角,贡献率为11.765%,第4主成分主要是倒二叶角,贡献率为11.132%。逐步回归分析法确定了株高、节数、茎粗、倒二叶角可以作为株型鉴定的主要性状。利用隶属函数综合评价法结合育种目标筛选出103、京选1号、44F、714R等30个优异种质资源。通过不同高粱品种类别间性状比较发现,改良种中的矮化、紧凑、抗倒伏趋势明显,更加符合现代化的生产要求。

This study attempted to investigate the phenotypic variation at nine plant architecture related traits(including plant height,stem diameter,and leaf related traits),via accurate identification and comprehensive evaluation of 371 domestic sorghum accessions,followed by the coefficient of variation,correlation analysis,cluster analysis,principal component analysis,and affiliation function F-value evaluation methods. Based on the phenotypic datasets from two years at two locations,the mean coefficient of variation ranged from 10.14% to 39.37%,and the genetic diversity index ranged from 1.94 to 2.14. These results revealed rich phenotypic variations in the germplasm collection,and visible variations for particular traits including internode number,the leaf angle of the second and third leaf from top,and stem diameter under environmental conditions. Based on cluster analysis,sorghum accessions were divided into three groups:Group Ⅰ was medium-culm spreading and medium-culm compact plants,Group Ⅱ was tallculm spreading plants and Group Ⅲ was short-culm compact plants. The nine traits were divided into four principal components by principal component analysis. The first principal component was mainly the straight stem,the leaf width of the second and third leaves from the top,and the number of internodes,with a contribution of 36.424%. The second principle component consisted mainly of plant height, the leaf length of the third leaf from the top and the leaf length of the second leaf from the top, with a contribution of 24.786%. The third principle component consisted mainly of the leaf angle of the third leaf from the top, with a contribution of 11.765%. The fourth principle component consisted mainly of the angle of the second leaf from the top,with a contribution of 11.132%. Stepwise regression analysis identified plant height,internode number,stem diameter,and the leaf angle of the second leaf from the top as the main traits that could be used for plant type analysis. Thirty elite germplasm resources,including 103,Beijing Selection No.1,44F,and 714R,were selected using the integrated evaluation method of the affiliation function in combination with breeding objectives. Through the comparison of traits between different sorghum variety categories,it is found that the improved varieties have a clear trend towards dwarfism,compactness,and resistance to overturning,which are more suitable for modern production requirements.