玉米雌穗扁平性状的遗传研究

GENETIC STUDIES ON THE CHARACTERIZATION OF FLAT EAR OF MAIZE(ZEA MAYS)

基于SAS分析软件,同时采用P1、P2、F1、F2、B1、B26个世代和混合模型,系统研究了玉米雌穗扁平性状的遗传特性及与其他穗粒性状的相互关系,估算了包括1对基因加性-显性模型等在内的23个模型的爱氏信息准则(AIC)值和极大似然函数值,并对AIC值最小的模型进行了混合模型参数估计。结果表明:(1)玉米扁平性状与穗粗、穗行数表现为极显著正相关;(2)玉米扁平性状符合E-1模型,即该性状受2对主效基因(a、b)与多对微效基因共同控制,表现为质量-数量性状。其中主效基因a与主效基因b的效应方向相反,并且主效基因b对扁平性状的贡献率大于a,2对主效基因间存在明显的上位性,而微效基因的加、显效应也有利于促进扁平性状的表现。

Based on the statistical analysis system （SAS） software and mixed genetic model, the genetic basis of flat ear in maize （ Zea mays） and its relation with other kernel-ear traits were studied using six generations （ P1 , P2, F1 , F2, B1 , B2 ） . The value of Akaike＇ s Information Criterion （AIC） and maximum likelihood function of 23 models were calculated. Genetic parameters of the model with minimum AIC value were calculated as well. The results were as following ： （ 1 ） the trait of flat ear positively correlated to ear width and row number per ear at 1% level ; （ 2 ） the flat ear of maize was a qualitativequantitative trait, and was controlled by two pairs of major genes （gene a and gene b） and some minor genes. And the two major genes had the opposite effects on the trait, and gene b had more contribution to the phenotype of flat ear than gene a. Additionally, there was obvious epitasis between these two major genes, and the additive and dominant effects among the minor genes could redound to incarnate flat ear.