玉米自交系表型性状主成分聚类分析研究

Cluster Analysis of Phenotypic Characters of Maize Inbred Lines Based on Principal Components

玉米作为重要的饲料作物和粮食作物，优良杂交种的选育和推广应用为玉米增产做出了突出贡献。杂种优势利用是玉米育种研究的重要内容，杂种优势理论建立在亲本遗传差异之上，因而种质遗传多样性研究是杂种优势利用的前提。该研究利用一批从国内外引进玉米优良种质资源选育而成的稳定自交材料，为有效利用这批新自交系，明确其应用潜力，采用了表型性状分析对其进行了遗传多样性研究，结果表明：供试的57份自交系间表型性状变异都集中在一个较小的范围内，各自交系间的欧氏遗传距离变幅为1.0108-11.0787，平均遗传距离为4.9345。当遗传距离为5.41时，可将57个自交系分为4个类群，各类群自交系各具特点，其中3号材料、9号材料植株较高，果穗较粗大，穗长、行粒数和百粒重等经济性状表现良好，是一个很好的高产育种潜力亲本；46号材料生育期较短、植株矮小，可在选育早熟、矮秆玉米组合上重点应用；其余自交系系各具特色，可结合不同育种目标有针对性地加以改良和利用，对玉米育种实践具有一定指导意义。

The narrow genetic diversity of maize breeding in China is a major constraint to the increasing of maize yield as a forage crop and food crop.Heterosis is an important aspect of the maize breeding research,heterosis theory is established based on parental genetic diversity,so the research of the genetic diversity of germplasm is the premise of heterosis.57 excellent stability of inbred lines material were selected from a number of excellent germplasm resources from home and abroad,for the effective use of these new electoral materials and making sure its potential applications,the research of their genetic diversity was necessary.The main results of phenotypic analysis showed that,the phenotypic variation of the inbred lines were concentrated in a small extent,and the genetic distances were among the euclidean ranged 1.010 8-11.078 7,with an average of 4.934 5.And when the genetic distance was 5.41,57 inbred lines were divided into 4 categories.Different inbred lines of different groups had different advantages,which had directive significance for maize breeding.Among them,inbred line’3’and’9’performed high plant height,big ear,as well as ear length,grain number and kernel weight,which were potential lines for high yield breeding.’46’had a short growth period and plant height,so it could be applied on breeding of early and drawf hybrids.As the other inbred lines,each with a distinct identity could be improved and utilized appropriately based on the different breeding objective,which had certain guiding significance for maize breeding practice.