动态性状主基因的分离分析新方法

A New Approach to Major Gene Segregation Analysis for Dynamic Traits

根据Legendre多项式的正交、可加和普适的特性,将关于时间的Legendre多项式镶嵌在遗传模型的每个遗传效应中,建立了动态性状主基因分离分析的数学模型,采用极大似然法求解模型参数。同建立在混合Logistic模型基础上的动态性状主基因分离分析法相比,新的方法在理论和实践上具有明显的优势:1)适合任何动态性状;2)能够同时分析主基因遗传效应和各种系统环境因素对动态性状变化过程的影响;3)便于计算;4)很容易推广到其他资源群体和复杂交配群体,充分利用多世代的资料实现对主基因的联合分离分析。以大豆1个F2群体为例采用新方法探索影响豆荚生长发育过程的主基因,结果表明:用2阶Legendre多项式能最佳的拟合主基因的作用和豆荚生长发育的变化规律;豆荚的生长发育过程受1对呈完全显性的主基因控制。

Based on the orthogonal, additive and universally practicable properties of Legendre polynomials, a new mathmatical model of major gene segregation analysis for dynamic trait was constructed by nesting Legendre polynomials within the effects of genetic and various environmental factors in genetic model. Maximum Likelihood method implemented via EM iteration was used to solve parameters in the model. Compared with the method on mixture Logistic model, the new method presented here performed remarkable advantages as： 1） it is suitable for any dynamic trait; 2） Ability to simultaneously analyze effects of genetic and various systemic environment factors; 3） it is convenient to solve, and 4） it is easy to be extended it to other resource populations and complicate mating populations, and to make full use of the material from multiple generations to jointly analyze major genes. The major gene was detected for developmental process of bean-pod in F2 population. It showed that the changing law of bean-pod growth development was fitted with the best precision by using 2 orders＇ Legendre polynomial and the developmental process of bean-pod was dominated by a major gene with full dominance.