Construction Of Chromosome Segment Substitution Lines And QTLs Mapping For Agronomic Traits In Cultivated Peanut

Peanut (Arachis hypogaea L.) is an important economic and oil crops in the world.Typical quantitative traits were presented with a lot of the important agronomic traits ofpeanut. However, the quantitative traits were controlled by multi gene of mini effects andeasily influenced by environments. Quantitative traits loci (QTL) mapping as a useful tooland effective method was widely employed to study quantitative traits. The excellentpopulation of QTL mapping was able to detect QTL accurately. Chromosome segmentsubstitution lines (CSSLs), as a superior population for its clear genetic background,genetic stability, precise of QTL mapping and genetic effect analysis and other advantages,can greatly accelerate the process of fine mapping. In the present study, a set of CSSL linesfrom a cross between Qinhuangdaoguangyang (hypogaea) as recurrent parent, andShiyaodou (fastifgiata) as the donor parent, was constructed and phenotypic evaluation andQTL mapping for agronomic traits were also conducted in two years and threelocations.The main results were summarized as follows:1. The CSSLs was composed of204lines with an average length of substitutedsegment of13.46cM, varying from2.2to99.27cM. Total length of the CSSLs was6903.27cM, which was1.79times of peanut genome. The recovery ratio of geneticbackground (RRGB) was98.84%on average, the smallest was97.19%, and99.72%of thelargest, all were higher than theoretical recovery ratio of genetic background96.875%.2.42chromosome single segment substitution lines were also screened as thebackground of Qinhuangdaoguangyang, the single segment substitutions were widelydistributed, involving the A subgenome7linkage groups including a02, a03, a04, a05, a06,a07, a10. b03, b05, b09linkage groups of B subgenome.3. A statistic analysis for some of the agronomic traits was carried out. The resultsshowed that the range of phenotypic value, and the variation coefficient were larger andrelatively continuous distribution, which accorded with normal distribution.4. A total of22QTLs were detected, including Pod width, Pod thick, Pericarpthickness, Reticulation thickness,100-pod weight,100-seed weight, Total branchingnumber, these QTLs additive effect value of-22.510-9.740, the explanation of thephenotypic variation rate was2.868%-13.523%.18QTLs additive effects show thereduction effect, additive effect value of-22.51--0.068, the explanation of the phenotypic variation rate was2.868%-13.523%, the four QTLs additive effect of synergy, additiveeffect value of0.046-9.740, the explanation of the phenotypic variation rate was3.990%-9.423%.5QTLs which control Pod width,6for Pod thick,2for Pericarpthickness,1for Reticulation thickness,3for100-pod weight,2for100-seed weight,3forTotal branching number, the contribution rate of5.608%-13.523%,2.868%-10.855%;7.650%-8.995%,7.570%,3.316%-8.034%,3.990%-9.423%,4.520%-12.681%, respectively.