Research On Synthesis Selection Index For Quantitative Characters Of Major-polygene And Polygene

With the development of the science and technology,and the statistical ideas in genetics, index selection of quantitative characters is studied and applied extensively, and while studying different population always relate to the index selection, especially when the theorem of genetic breeding is developed quickly. But the former study on index selection was only on the single characters or the poly-gene characters, and fewer studied on mixing the major-polygene and polygene. In fact, the relationship of characters is not controlled by the polygene simply, that is we need to resolve the synthesize selection index of two quantitative characteristic genetic system, major-polygene and polygene, guiding for the work of breeding.The performance of the quantitative characteristic polygene nearly obeys the normal distribution, but major-polygene is showed multimodal or skewness,it accounts for this mixture of some normal distributions, that is the selection must be different from usual quantitative analysis in model , and need to compartment analysis with the mixed normal distributions firstly. There for, this paper using compartment analysis with the mixed normal distributions'EM method, with the help of the results of the non-segregating to estimate phenotypic variance,hereditary variance,heritability et al, giving the model of the synthesize selection index of two quantitative characteristic genetic system, major-polygene and polygene on the basic of classical theory, in order to combine the QTL better .The specific methods are as follows:First, using the date of non-segregating generations to estimate environmental variance; second, using frequency distribution of different characters to study which one belongs to major-polygene and polygene. We can get the parameter vectors we need if it is polygene, but we need to compartment analysis with the mixed normal distributions to get the parameter vectors if it is major-polygene; third, being based on the two steps, and combining with the classical theory of synthesize selection index, counting the phenotypic variance,hereditary variance,heritability and genetic gain, building the model of Synthesize selection index for quantitative characters of major-polygene and polygene, giving the result of impact. If the major gene is most, we can use QTL method to control it to master the character. This method is better to select the species.In addition, the model and method of this paper could be extended; it used mixed only one major-polygene and polygene, this method can popularize to the situation of one major-polygene and multi-polygene or multi-major-polygene and a polygene or different state of affairs.