水稻单株有效穗数主基因+多基因混合遗传分析

Genetic Analysis of Panicles per Plant in Rice by the Major Genes Plus Polygenes Mixed Inheritance Model

选择单株有效穗数差异大的3个亲本CB1(15.3)、CB4(6.4)和CB7(11.8),配制CB1×CB4和CB7×CB4组合,建立了相应的P_1、F_1、P_2、B_1、B_2、F_2群体,将其分为中、晚两个生产季节种植,考察了有效穗数性状.利用主基因+多基因混合遗传模型理论的Akaike信息准则(AIC)在B_1、B_2、F_2代中鉴定影响数量性状的主基因存在与否,主基因存在时通过分离分析估计主基因和微效基因的遗传效应及所占总变异的分量.结果表明该性状在所有B_1、B_2、F_2中均符合2对加性-显性-上位性主基因+加性-显性-上位性多基因的遗传模式,主基因遗传率为30.64%-72.26%,多基因遗传率为3.41%-28.20%,总基因遗传率为45.96%-87.29%;相同组合种植季别主基因遗传率及一阶参数对比表明,杂交亲本的选择及种植季别对该性状遗传率影响较小,h_a、h_b、j_(ab)、j_(ba)值均为负值表明显性效应和加性显性互作对该性状表达具有抑制作用.

Three rice parents with great difference in panicles per plant CB1（15.3）、CB4（6.4）and CB7（11.8）were chosen to construct the combines CB1×CB4 and CB7×CB4,also the corresponding P_1、F_1、P_2,B_1,B_2,F_2 populations were established and planted as middle and late two planting seasons and the panicles per plant traits were checked,respectively.The Akaike＇s information criterion（AIC） of the major genes plus polygenes mixed inheritance model was used to indentify the existence of major genes affecting quantitative traits in B_1,B_2,F_2 populations, and when the major genes existed,the genetic effects of the major genes and polygenes and their genetic variance were estimated through segregation analysis.Two additive,dominance and epistasis major genes plus additive-dominance-epistasis polygenes was the most fitted genetic model for this trait in all the B_1,B_2,F_2 populations.The heritability values of the major genes varied from 30.64 percent to 72.26 percent and those of polygenes varied from 3.41 percent to 28.20 percent,and the total heritability values were from 45.96 percent to 87.29 percent.Genetic of the trait was little affected by the hybrid parents and planting seasons selection after contrasting the major genes heritability and the first order parameter of the same combine,and h_a、h_b、j_（ab）、j_（ba） were all negative suggesting dominance and additive-dominance interaction might depress expression of the trait.