20个玉米自交系穗部性状配合力及相关性分析

摘要

The combining ability and correlation of eight ear characteristics in 99 maize hybrids generated by crossing nine female parents with 11 male parents were analyzed by incomplete diallel cross (NC Ⅱ) design.The results showed that the line F6 had the highest general combining ability (GCA) for yield,followed by F7,M3,M4 and M8.All of the five lines have great potential in maize breeding.The cross combination M3×F10 had the highest specific combining ability (SCA) for yield,showing strong heterosis.Heritability analysis of ear characteristics showed that GCA variance was higher than SCA variance in ear diameter,number of rows per ear and seed rate,and they were mainly controlled by the additive gene effect,indicating that that the selections for these traits are effective at early generations.The other three traits had lower SCA,for which the selections should be carded out at late generations.The correlation analysis revealed that ear length,number of grains per row,ear diameter,number of rows per ear,100-seed weight and seed rate had extremely significant positive correlations with grain yield per plant.Among them,number of grains per row had the most significant effect on yield per plant.Barren tip length had a significant negative correlation with grain yield per plant.Therefore,we concluded that the combinations with more grains per row and shorter barren tip should be selected to achieve high yield of maize.%采用NCⅡ设计,对9个母本与11个父本组配的99个杂交组合进行穗部性状配合力分析和性状之间的相关性分析.结果表明,产量一般配合力效应值以F6最高,F7、M3、M4和M8次之,这些材料具有较大的育种利用潜势;特殊配合力效应值最高的组合是M3×F10.穗部性状遗传力分析表明,穗粗、穗行数、出籽率的狭义遗传力较高,且加性效应占主导地位,可早代进行选择;其余性状的狭义遗传力偏低,宜晚代进行选择.相关性分析表明,穗长、行粒数、穗粗、穗行数、百粒重及出籽率均与单株产量呈极显著正相关,以行粒数的作用最大;秃尖长与单株产量呈显著负相关.因此,在选育高产品种时,应注重对行粒数的筛选,同时注意秃尖较短的选系.