植物数量性状诱发突变的数学模型

本文提出了一种植物数量性状诱变的数学模型——混合分布模型。该模型将诱变后代群体分解成正常与突变两个子群体,总群体中性状的分布由两个子群体的分布混合而成。利用信息条件最小X~2估计方法,可以估计出总群体及两个子群体的均值和方差,以及突变子群体占总群体的比例,即突变率,并由此确定分布的形式。从两个子群体的方差还可估算出突变性状的广义遗传力。另外,该模型能够推广到多元情形,并举出了一个实例。

A MATHEMATICAt MODEL FOR PLANT MUTAGENESIS IN QUANTITATVE CHARACTERS

In this paper, a mathematical model-tke Mixed Distribution Model-for plant mutagenesis in quantitative characters is proposed.Accordingto the model, when a given character is taken into account, a plant mutation progeny's population or the General Population (GP) , such as M2generation,can be divided into two subpopulations-the Normal Subpopu-lation ( NS ) which consists of plants appearing normal in the character andthe Mutant Subpopulation ( MS ) which consists of corresponding mutants-and the character's distribution in the GP is a mixture of two distributions of the NS and MS.By means of the Information-Condition Minimum Chi-square Estimation method, mean values and variances of the GP, NS and MS and the proportion of the MS to the GP or the mutation rate can be estimated and therefore the forms of the distributions can be confirmed. The broad heritability of the mutation character can also be calculated from the variances of the NS and MS.Moreover, the model can be extended to multi-element situations, from which more useful and more accurate information can be obtained. An example is given.