玉米果穗相关性状的配合力及其遗传效应分析

Combining Ability and Hereditary Effect of Ear-related Characters in Maize

为了明确玉米果穗相关性状的配合力及其遗传效应,按NCⅡ遗传交配设计,对参试的20个玉米自交系(9个母本,11个父本)的9个性状的一般配合力、特殊配合力、广义遗传力、狭义遗传力进行分析。结果表明,5个自交系JZF5、JZF2、JZM10、JZM5、JZM3在穗粒重等多个性状上兼具一般配合力(GCA)有益的显著或极显著值。穗粒重特殊配合力(SCA)排名前5的杂交组合JZF5×JZM4、JZF2×JZM1、JZF8×JZM5、JZF6×JZM5、JZF7×JZM5,它们的亲本之一穗粒重GCA为极显著正值,提示在杂交种组配时应兼顾GCA和SCA效应。穗长、秃尖长、行粒数、穗行数、水分含量加性遗传方差占比大于70%,穗粒重的加性遗传方差占比为35.7%,主要由非加性遗传方差构成。广义遗传力上,水分含量>秃尖长>穗行数>穗长>穗粒重>行粒数>穗轴重>穗宽>百粒重,其中秃尖长、穗行数的广义遗传力大于60%,水分含量的广义遗传力大于70%。狭义遗传力上,秃尖长>水分含量>穗行数>穗长>行粒数>穗轴重>穗宽>百粒重>穗粒重,其中秃尖长、水分含量和穗行数的狭义遗传力大于50%,适宜在早代进行选择;百粒重和穗粒重的狭义遗传力最低,分别是22.8%和19.7%,不宜在早代进行选择。本研究的果穗部分性状供试特性偏向父本,建议关注父本对玉米杂交种果穗相关性状的重要影响。

To clarify the combining ability and genetic effects of ear-related traits in maize, according to NC II genetic mating design, the general combining ability(GCA), special combining ability(SCA), the broad-sense heritability(HB^2) and the narrow-sense heritability(HN^2) were analyzed for 9 traits of 20 maize inbred lines(9 female parents and 11 male parents). The results showed that five inbred lines, namely JZF5, JZF2, JZM10,JZM5 and JZM3, were beneficially significant or extremely significant in GCA of multiple traits. JZF5*JZM4,JZF2*JZM1, JZF8*JZM5, JZF6*JZM5 and JZF7*JZM5 was the top five for the SCA in kernel weight, one of their parents had a very significant positive GCA for kernel weight, which suggested that both GCA and SCA effects should be taken into account in hybrid combinations. The additive genetic variance of ear length, bald tip length, grain number per row, row number and water content were greater than 70%. The additive genetic variance of kernel weight was 35.7%, which was mainly composed of non-additive genetic variance. For the HB^2, water content > bald tip length > row number > ear length > kernel weight > grain number per row > cob weight > ear width > 100-grain weight, and the HB^2 of bare tip length and row number were more than 60%,and the HB^2 of water content was more than 70%. For the HN^2, bald tip length > water content > ear row number > ear length > grain number per row> cob weight > ear width > 100-grain weight >kernel weight, the HN^2 of bald tip length, water content and ear row number were more than 50%, suitable for early generation selection;the lowest HN^2 was found in 100-grain weight and kernel weight, 22.8% and 19.7% respectively,which were not suitable for selection in early generations. In this study, some ear characters are more male parental, suggesting that more attention should be paid to the important effects of male parents on ear-related traits of maize hybrids.