玉米叶夹角、叶向值主基因十多基因遗传模型分析

摘要

为探讨玉米叶夹角、叶向值的遗传规律,以7873/PH6WC的六世代P1、P2、F1、B1、B2、F2为材料,在春播和夏播环境下,田间分穗上、穗下调查叶夹角和叶向值,对其主基因十多基因遗传模型进行分析.结果表明,在春播和夏播环境下,穗上叶夹角和穗上叶向值最适模型均为E-1模型,存在2对主基因.穗下叶向值在春播和夏播环境中都符合D-2模型,存在1对主基因.穗下叶夹角在春播环境中符合D-2模型,但在夏播环境中没有检测到主基因,属于多基因遗传模型(即C-0模型).夏播环境中,穗上叶夹角、叶向值、穗下叶夹角均检测到较高的主基因贡献率.夏播环境中,穗上叶夹角F2世代的主基因遗传率为85.60％,穗上叶向值主基因遗传率在B2和F2世代分别为88.92％、88.69％,穗下叶向值在B2世代的主基因遗传率为82.43％.但春播环境中,只有穗上叶向值在F2世代有较高的主基因遗传率(90.27％).玉米叶夹角和叶向值存在较大的主基因遗传率,可以采用单交重组或简单回交转育的方法进行遗传改良.%The major genes plus polygenes genetic rules of leaf angle and leaf orientation value in maize were studied to provide some theoretical references for improving maize yield through density-tolerance plant type breeding. The leaf angle and leaf orientation value above the upmost ear and below the upmost ear of six generations (P1 ,P2 ,F1,B1 ,B2,F2) of cross 7873/PH6WC were recorded and analyzed by major genes plus polygenes joint analysis of multiple generations method in spring and summer sowing environments. Results showed that the optimum models of leaf angle and leaf orientation value above the upmost ear in the two environments were E-l modeUand 2 pars of major genes were detected. One pair of major genes was detected for leaf orientation value below the upmost ear in both environments and the most fitting model was D-2 model. Leaf angle below the upmost ear was controlled by model D-2 in spring sowing environment,while its optimum model in summer sowing environment was C-0 model without any major gene detected. High heritability of major genes was detected for leaf angle and leaf orientation value above the upmost ear and leaf angle below the upmost ear in summer sowing environment. Under summer sowing condition, the heritability of major genes of leaf angle above the upmost ear in F2 generation was 85. 6% , those of leaf orientation value above the upmost ear in B2 and F2 generation were 88. 92%,88. 69%籸espectively, while that of leaf orientation value below the upmost ear in B2 generation was 82. 43%. However,only leaf orientation value above the upmost ear had high heritability of major genes(90. 27%) under spring sowing condition. Accordingly,single cross recombination and simple backcross could be applied to cumulate positive major genes of leaf angle and leaf orientation value,to achieve genetic improvement of maize.