QTL Mapping Of Major Agronomic Traits And Marker-assistant Selection In Soybean

In this study, F2population obtained from Jiyu50and Jinong18hybrids as material, bymeans of SSR molecular marker technology, the soybean SSR local high density genetic mapwas constructed, and the soybean plant height, first pod height, number of main stem nodes,number of valid branchs,100-seed weight, weight of seeds per plant, number of seeds per plant,number of pods per plant, stem diameter, stem weight.These10main agronomic traits of QTLmapping and marker-assisted selection were studied for the main quality traits. The results are asfollows:1．On the basis of the previous work,50SSR primers were selected from the three moreintensive distribution QTL genetic linkage groups,12（G）,13（C1）and15（I），as a result,10polymorphic SSR primers were screened by parents.2．Using SSR molecular marker technology,10SSR primers were integrated into threelinkage groups based on SSR genetic map from the material of a F2population consisting of259individuals. Among these, the total length of12（G）linkage group was266.82cM, the averagedistance between markers was16.68cM, ranging from3.78to76.72cM; the total length of13（C1）linkage group was102.89cM, the average distance between markers was12.86cM,ranging from5.05to54.33cM; the total length of15（I）linkage group was136.99cM, theaverage distance between markers was27.40cM, ranging from24.09to44.12cM.3．With the application of the QTL IciMapping v3.2software, combined with molecularmarkers and phenotypic data, the soybean plant height, first pod height, number of nodes onmain stem, number of valid branchs,100-seed weight, weight of seeds per plant, number ofseeds per plant, number of pods per plant, stem diameter, stem weight of F2populations wereconducted complete interval map, with scanning step length of1.0cM, LOD threshold value of2.5, analysing QTL mapping and effect,24QTLs were detected.4．Using the6SSR primers associated with soybean protein and fat content, namelySatt100, Sat₂87, Satt199, Satt636, Sat₂38and Satt396, which have been positioned in thepreliminary work, high oil, high protein molecular marker were detected among the180copiesof40strains of F4plant which were extracted randomly from the soybean germ plasm nurseryof jilin agricultural university. The effect of MAS was verified preliminarily, providing a basisfor the further application of MAS to breeding high oil, high protein soybean varieties.