遮阴条件下玉米自交系配合力与遗传效应分析

Analysis of Combining Ability and Genetic Effect of Maize Inbred Lines under Shading Condition

为了利用杂种优势改良玉米品种的耐阴性,以10个耐阴性不同的玉米自交系为亲本,按照NC II4×6遗传交配设计,对遮阴和自然光照下玉米的产量及穗部性状的配合力、遗传参数进行分析。结果表明,产量、穗长、秃尖长、穗粗、穗行数、行粒数和百粒重7个性状在自然光照和遮阴处理下差异均达极显著水平,遮阴处理下昌改3、R2005、LYM35、LYM10这4个自交系的一般配合力较高,特殊配合力也较高,杂种优势也强,可作为玉米耐阴性遗传改良的候选亲本。LYM35×昌改3在遮阴处理下的特殊配合力效应值较高,在遮阴处理下表现优异,是耐阴性较强的组合。遗传参数分析表明,产量、穗长、穗粗、秃尖长和穗行数在遮阴处理下的狭义遗传力相对较高,可以在早代进行耐阴选择,行粒数和百粒重的狭义遗传力较低,广义遗传力较高,应在育种高世代进行选择。

In order to improve the tolerance of maize varieties with heterosis,ten inbred lines with different shading tolerance were used as parents,combining ability and genetic parameters of yield and ear characteristics under shading and natural light were analyzed according to NC II 4×6 genetic mating design.The results showed that there were extremely significant differences in yield,ear length,bald tip length,ear diameter,row number per ear,grain number per row and 100-grain weight under natural light and shade treatments.The four inbred lines of Changgai 3,R2005,LYM35 and LYM10 had high general combining ability,high special combining ability and strong heterosis under shading treatments,which could be used as candidate parents for shading resistance genetic improvement of maize.The special combining ability effect value of LYM35×Changgai 3 was higher in shading treatments,and it showed excellent performance in shading treatments.Genetic parameter analysis showed that the narrow heritabilities of yield,ear length,ear diameter,bald tip length and row number per ear under shading treatments were relatively high,which could be selected for shading tolerance in early generations.The narrow-sense heritabilities of grain number per row and 100-grain weight were low,but the general heritabilities were high,selection should be made in high breeding generations.