20份玉米自交系主要性状配合力及杂种优势分析

Combining Ability and Heterosis Analysis on Main Traits of 20 Maize Inbred Lines

为筛选优良玉米自交系和杂交组合,用20个玉米自交系按照12×8 NCII遗传交配设计配制96个组合,对单株产量等11个主要性状的配合力、遗传力和杂种优势进行分析。结果表明,自交系B4、A2、A5、B7、A3和B2的单株产量一般配合力效应值较高,组合A11×B2的单株产量特殊配合力效应值最高,有8个杂交组合的单株产量对照优势超过15%,分别为A9×B4、A11×B2、A2×B6、A3×B7、A10×B4、A5×B7、A2×B4、A6×B1,可进一步鉴定;遗传力分析表明,株高、雄穗主轴长、穗位高、雄穗分枝数、籽粒含水量、穗粗、穗行数、秃尖长8个性状的广义遗传力和狭义遗传力均较高,可在早代选择。穗长、行粒数、单株产量3个性状的广义遗传力较高,但狭义遗传力较低,适合在晚代选择;组合F 1的表型值与亲本的一般配合力和组合的特殊配合力均呈极显著正相关,配合力贡献率因性状而异;组合的单株产量杂种优势与亲本的一般配合力、组合的特殊配合力均呈极显著正相关,且组合的特殊配合力对杂种优势的贡献更大;亲本一般配合力与组合特殊配合力之间几乎没有相关性。

In order to select excellent inbred lines and hybrid combinations in maize,the combining ability,heritability and heterosis of 11 main traits such as yield per plant were analyzed by using 96 combinations of 20 maize inbred lines according to 12×8 NCII genetic mating design.The results showed that the general combining ability effect values of yield per plant of inbred lines B4,A2,A5,B7,A3 and B2 were higher,and the special combining ability effect values of yield per plant of combinations A11×B2 was highest.The control heterosis of yield per plant of 8 hybrid combinations exceeded 15%,which were A9×B4,A11×B2,A2×B6,A3×B7,A10×B4,A5×B7,A2×B4 and A6×B1,respectively,which could be further identified.Heritability analysis showed that the broad-sense heritability and narrow-sense heritability of plant height,tassel length,ear height,tassel branch number,grain moisture content,ear diameter,ear row number and bald tip length were high,which could be selected in early generation.The broad-sence heritability of panicle length,grain number per row and yield per plant was high,but the narrow-sence heritability was low,which was suitable for selection in late generation.The phenotypic value of F 1 was significantly positively correlated with the general combining ability of parents and the special combining ability of combinations,and the contribution rates of combining ability varied with traits.The heterosis of yield per plant of combinations was significantly positively correlated with the general combining ability of parents and the special combining ability of combinations,and the special combining ability of combinations contributed more to heterosis.There was almost no correlation between general combining ability and specific combining ability.