QTL Analysis For Yield-related Pod Traits And Quality Traits Of Seed In Peanut(Arachis Hypogaea L.)

Arachis hypogaea L.is a widely planted economic and oil crop worldwide.Peanut are the fourth largest domestic crop in China.It is of great importance to carry out research and analysis of peanut traits,such as yield,pod size,oil content,etc.The use of molecular marker-assisted breeding to breed some fine cultivars has important theoretical and practical value.In this study,the materials were recombination inbred lines from “Shanhua15×Zhonghua 12”.Based on the preliminary experiment,a genetic linkage map of molecular markers was constructed.QTL mapping were performed based on the investigation data of pod traits and quality-related traits.The main research results obtained are as follows:1.Analyze the phenotypic data of peanut yield-related pod traits and quality traits of seed.The parents were significant difference in single-pod weight,single-seed weight,oil content,oleic acid content,linoleic acid content,palmitic acid content,tetracosanoic acid content,behenic acid content,and crude protein content.The RIL population varied widely in 6 yield-related pod traits and 19 quality traits of seed.The minimum value of the coefficient of variation was 4.39% and the maximum was 35.88%.There were super-parental lines in the population.The 25 traits all showed continuous variation and were typical quantitative traits.2.A genetic linkage map of cultivar peanut with 190 markers was constructed.There were 23 linkage groups.The total length was 1980.22 cM,the average distance between markers was 10.42 cM,and the minimum distance between markers was 0.30 cM.The average length of linkage group was 86.09 cM,and the number of individual linkage group marker was 2-19.3.QTLs for yield-related pod traits and quality traits of seed were located by software QTL IciMapping V 4.0.A total of 216 QTL were detected,including 4 QTL for pod weight,9 QTL for seed weight,3 QTL for shelling percentage,7 QTL for total pod weight per-plant,10 QTL for oil content,67 QTL for fatty acid content,12 QTL for crude protein content and 104 QTL for amino acids content.The PVE of individual QTL was 1.75%~13.40%.11 QTL were detected repeatedly in the four planting environments,2014,2015,2016 and 2017.The PVE of QspwA07 related to single-pod weight was 5.41%~10.43%,the PVE of QsswA07 related to single-seed weight was 5.46%~10.76%,the PVE of QocA07 related to oil content is 4.85%~9.32%.The three QTL were located between two markers,AHGS1213_c1 and GM2050,closely linked to the marker GM2050.The genetic distances were 4.19 cM,3.94 cM,and 2.19 cM,respectively.The PVE of QcpcA04-1 related to crude protein content was 4.45%~13.17%,it was located between two markers,PM427 and AHGS1143,closely linked to the marker AHGS1143.The genetic distance was 3.71 cM.The PVE of QbaB02 related to behenic acid content was 3.96%~11.69%,PVE of QtaB02 related to tetracosanoic acid content was 3.13%~5.39%,the PVE of QlysA07 related to lysine content was 2.92%~7.78%,the PVE of QleuA07 related to leucine content was 2.83%~4.80%,the PVE of QthrA07 related to threonine content was 3.73%~9.22%,the PVE of QvalA07 related to valine content was 5.24%~11.14%,and the PVE of QileA07 related to isoleucine content was 5.60%~8.03%.4.A total of 44 regions containing two or more trait-related QTL were detected.In the ALGS1213_c1~GM2050 marker interval of LG07(A07)linkage group,QTL related to 19 traits were detected,such as single-pod weight,single-seed weight,hundred-pod weight,hundred-seed weight,shelling percentage,crude protein content and oil content.The genetic distance between the two markers was 27.29 cM,and the above QTL were closely linked to the marker GM2050.The QTL clusters on the LG4(A04),LG7(A07),and LG13(B02)linkage groups contained more than 10 trait-related QTL.5.A total of 15 co-separation markers with QTL were detected,nine of co-separation markers with single QTL,which were AHGS1500_c1,AHGS1755,AHGS1358,GM1771,AHS2274_c1,AHGS1211,TC4H02,AHGS2526 and AHGS3217 with single-seed weight,crude protein content,tetracosanoic acid content,behenic acid content,palmitic acid content,methionine content,arginine content,valine content and threonine content respectively.Six co-separation markers with multiple QTL were AHGS1434,AHGS1917_c1,IPAHM229,GM2050,AHGS1280 and TC25G11,respectively.