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The Statistical Method Involved In Genetic Mapping Of The Fertility Restorer Gene For Cytoplasmic Male Sterility In Plants

Posted on:2015-03-23Degree:MasterType:Thesis
Country:ChinaCandidate:J S HuFull Text:PDF
GTID:2180330467450527Subject:Genetics
Abstract/Summary:PDF Full Text Request
Discovering new restorer gene and estimating the position of restorer gene will have important theoretical and practical significance of the utilization of heterosis to improve the production of crop, to have a better understanding of cytoplasmic male sterility and its restoring mechanism. Due to the interaction between restorer gene is often diversity, even within a species, fertility restoration may also be controlled by different restorer gene, and by different ways.This thesis set up two kinds of genetic models to study the genetic mapping of restorer gene for cytoplasmic male sterility. Developed maximum likelihood solution and using the segregation information of molecular markers linked to restorer gene for the estimating of parameters to analysis different sample size and recombination rate in coupling phase、repulsion phase、gametophytic and sporophytic of F2single loci and F2two loci model.The results are as follows:1. Two genetic models for different molecular markers were developed, which were F2single loci model and F2two loci model. Formulae for estimating the recombination rate of complete marker information by means of maximum likelihood. If you know which marker linked to this restorer gene, you can choose F2single loci model, but if you don’t know which marker linked to this restorer gene, you can choose F2two loci model.2. The bias, standard error and MSE of parameters were estimated with simulation method, and were used to evaluate the influences of different sample size and recombination rate on the estimating of parameters. The result showed that in F2single loci model and F2two loci model, different sample size have an obvious effect on the estimating of parameters, every parameters in the influences of different sample size, codominant, dominant-repulsion, dominant-coupling of gametophytic and sporophytic were estimated with the best accuracy under large recombination rate; the sample size larger than270were estimated with the best accuracy in F2single loci model, the sample size larger than570were estimated with the best accuracy in F2two loci model. Different recombination rate also have an obvious effect on the estimating of parameters, codominant, dominant-repulsion, dominant-coupling of gametophytic and sporophytic were estimated with the best accuracy under smaller recombination rate; in the circumstance of gametophytic and sporophytic in F2single loci model and F2two loci model, the estimating effect of codominant is the best, the estimating effect of dominant-coupling model take second place, the estimating effect of dominant-repulsion is the worst; the estimating effect of F2two loci model is better than the estimating effect of F2two loci model.
Keywords/Search Tags:Cytoplasmic male sterility, Restorer gene, Genetic model, Maximumlikelihood, Parameter estimate
PDF Full Text Request
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