基于主成分、聚类和灰色关联度分析的超甜玉米杂交组合综合评价

Comprehensive evaluation of super sweet maize cross combinations based on principal component analysis,cluster analysis and gray correlation analysis

【目的】对超甜玉米杂交组合进行综合评价,为筛选优良超甜玉米杂交组合提供理论参考。【方法】对26个超甜玉米杂交组合和晋超甜一号(对照,CK)的9个农艺性状、品质及产量进行遗传变异分析,并利用主成分分析法、系统聚类分析法及灰色关联度分析法对超甜玉米杂交组合进行综合评价。【结果】26个超甜玉米杂交组合的性状差异较大,变异丰富,变异系数为6.25%~74.44%,其中,以秃尖长的变异系数最大,穗粗的变异系数最小。通过主成分分析发现,前5个主成分(产量因子、品质因子、穗行数因子、秃尖长因子和生育期因子)累计贡献率为87.7414%,可代表11个性状所反映的遗传信息,且筛选出综合得分高于CK的杂交组合,依次为TJ22、TJ3、TJ17、TJ15、TJ10、TJ11、TJ19和TJ12。通过聚类分析发现,26个超甜玉米杂交组合可聚成三大类群,第Ⅰ和Ⅱ类群又分别聚成2个亚类群,其中第Ⅱ和Ⅲ类群的产量和品质明显优于第Ⅰ类群。通过灰色关联度分析发现,穗粗、行粒数和穗长对品质影响较大,单穗重、穗粗和行粒数对产量影响较大,穗位高和秃尖长对品质和产量的影响均较小,且筛选出与参考品种关联度排名前10位的杂交组合,依次为TJ22、TJ3、TJ15、TJ17、TJ11、TJ10、TJ19、TJ12、TJ4和TJ26,均高于参考品种与CK的关联度。通过主成分分析筛选出的8个优良杂交组合和通过灰色关联度分析筛选出的10个优良杂交组合均处在第Ⅱ和Ⅲ类群。【结论】筛选出的8个产量高、品质优、综合性状好的杂交组合(TJ22、TJ3、TJ17、TJ15、TJ10、TJ11、TJ19和TJ12),可进行单地点品种比较试验。第Ⅱ和Ⅲ类群的其他组合还需通过杂交或回交进一步改良。

【Objective】To provide theoretical reference for screening fine super sweet corn hybrids,comprehensive evaluation of super sweet corn cross combinations was conducted.【Method】The genetic variation of 9 agronomic characters,quality and yield of 26 super sweet maize cross combinations and Jinchaotian 1(control,CK)were analyzed,and principal component analysis,system cluster analysis and grey correlation analysis were used to evaluate the hybrid combinations of super sweet corn.【Result】Characteristics of 26 super sweet maize cross combinations had large differences and abundant variations,and the variation coefficient was from 6.25%to 74.44%.Among them,the variation coefficient of bald tip length was the largest,and that of ear diameter was the smallest.According to the principal component analysis,the cumulative contribution rate of the first five principal components(yield factor,quality factor,ear row number factor,bald tip length factor and growth period factor)was 87.7414%,which could represent the genetic information of 11 characters.The hybrid combinations with higher comprehensive scores than CK were selected,they were TJ22,TJ3,TJ17,TJ15,TJ10,TJ11,TJ19 and TJ12.Through cluster analysis,26 super sweet cross combinations were grouped into three groups,ⅠandⅡwere divided into two subgroups respectively.The yield and quality of groupsⅡandⅢwere better than that of groupⅠ.Grey correlation analysis showed that ear diameter,row grain number and ear length had great influence on the quality of super sweet maize;single ear weight,ear diameter and grain number per row had great influence on yield.Ear height and bald tip length had little effect on quality and yield.The top 10 cross combinations were TJ22,TJ3,TJ15,TJ17,TJ11,TJ10,TJ19,TJ12,TJ4 and TJ26,whose correlation with reference varieties were all higher than correlation between reference varieties and CK.Eight excellent combinations selected by principal component analysis and ten excellent combinations selected by grey relational grade analysis were all in groupsⅡandⅢ.【Conclusion】Selected eight excellent hybrid combinations(TJ22,TJ3,TJ17,TJ15,TJ10,TJ11,TJ19 and TJ12)with high yield,good quality and good comprehensive characters can be carried out single site variety comparison test.Other combinations of groupsⅡandⅢneed to be improved by crossing or backcrossing.