| Peanut is an important oil crops and economic crops. China is the biggest country on production, consumption, and export of peanut in the world. Yield, quality and disease resistance are typical complex quantitative traits, traditional breeding methods is difficult to simultaneously improve many traits in peanut. With the development of modern genetics and molecular biology, complex traits can be decomposed into simple Mendelian genetic factor, so it is possible to manipulate the complex quantitative traits in crop improvement for yield, quality and disease resistance, using the method of marker-assisted selection (MAS). Therefore it is necessary and very important theoretically and practically to study the inheritance of yield, quality, disease resistance and the other important traits in peanut, to construct the linkage map, as well as the QTL mapping. In present research, molecular genetic map was constructed in peanuts, using several genetic populations included recombinant inbred lines (RILs) and F2 population as materials, based on SSR molecular markers and integrate experimental data of two year's environments, the genetic effects of agronomic traits on yield, quality, and disease resistance, as well as their QTL are studied, and the main results are as follows:1. A recombinant inbred lines (RIL) derived from Zheng8903×Yuhua 4 in Arachis hypogaea L was developed. Investigation of 20 traits related to yield, quality and disease resistance showed that all the traits except of resistance disease trait in groups were conformed to the normal distribution, suitable in studying for inheritance of quantitative traits and QTL mapping.2. Using the developed RILs population derived from a cross of "Zheng8903×Yuhua 4" as the material, and joint segregation analysis of major gene with minor genes mixed inheritance model as method, the inheritance of yield, quality and the resistance to web blotch disease in peanut were analyzed. As the results showed that main stem length, total bearing branches, mature pods per plant and kernel percent were controlled by three major genes, and those of 100-pod weight and 100-kernel weight followed two major genes with several minor genes. The inheritance of protein content in peanut was complied with the non-major gene model, and the fat was controlled by two major gene with several minor genes, while those of oleic acid content, linoleic acid content and palmitic acid content were controlled by two major genes only, and O/L and Behenic acid content were controlled by three major genes. The disease resistance to web blotch was controlled by three major genes with several minor genes as well. For the heritability, the results showed that those of oleic acid content, linoleic acid content and palmitic acid content were over 60%, and that of the disease resistance to web blotch was over 80%, which belong to the quality traits controlled by major gene(s).3. Using a RIL population derived from the cross of "Zheng8903×Yuhua 4" as the basic population, combined with other the RIL population derived from "Zheng9001×Zheng8903" and two F2 population, "Baizi×Yuhua 4", "Kainongbai 2×Yuhua 4", with the help of the Join Map 3.0 and Map Chart 2.1, a composite linkage map of Arachis hypogaea L. including 17 linkage groups and 101 marker loci was constructed. The linkage map was 953.88 cM in total length with the longest linkage group of 14 SSR markers and was 158.8 cM.4. The 62 additive QTLs related to shape, yield, quality(fat, protein, fatty acids) and the disease resistance to web blotch in peanut were mapped through the jointed linkage map based on a RILs population derived from Zheng8903×Yuhua 4, and field investigation data from two years and two locations, using the software of WinQTLCart 2.5 and QTLNetwork 2.0. And selected 18 loc trait closely linked QTL (genetic distance of less than 3 cM) of the 22 SSR markers, molecular marker assisted breeding to the establishment of technology has taken a solid step forward.
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