Mapping Of Quantitative Trait Loci For Major Agronomic Traits In Summer Soybean

It is an important content and basis of plant genomics to construct genetic linkage map with recombinant inbred line group as the research material and QTL analysis of its main characters.In this study,the F2:7 and F2:8 recombinant inbred lines,which was derived from the cross of cultivated soybean Gong 387-1 and Ya'an Heidou,were used as the research materials for constructing the genetic map by SSR molecular.The QTL analysis of 15 main agronomic and kernel characters,such as plant height,number of pod per plant,number of seed per plant,seed weight per plant,100-seed weight,seed coat color and so on,was carried out,the main results were as follows:500 SSR markers covering 20 linkage groups of soybean were selected,and a genetic map of 70 polymorphic markers distributed in 19 chain groups was constructed,containing1788.06 cM,and the average distance between markers was 26.30 cM.On the whole,SSR markers were more evenly distributed on this map,and there were more densely marked regions,which were located on the linkage groups of N,M,O,B2,L,and there were also larger space.Compared with the public genetic map,although the marker numbers were less,the location and distance of markers were more consistent with the public genetic map.Using mapping complete interval mapping method,a total of 11 QTL loci of 4characters were detected,and distributed in the linkage groups of d₁b,A₂,B,B₂ in 2016.A total of 16 QTL loci of 6 characters were detected,and distributed on 10 linkage groups in2017.Although the detected locus of 100-seed weight were differentl in the two-year,but its contribution rate were all greater than 10%.BE021153 locus located in the 2nd linkage group were correlated with the plant height in the two years,and the position was closer.By QTL analysis of environmental and genetic interactions,2 locus related plant height,2locus related number of pod per plant,one locus related respectively number of blighted pod,mumber of grain per plant,seed weight per plant,and 2 locus related 100-seed weight were deteceted.By analyzing the interaction between gene superior and environment,one pair QTL locus related plant height,4 pairs QTL loci releted number of branch per plant,one pair QTL locus releted seed weight per plant were detected,and they all be located in linkage group A_2..Using the mutation posterity of Yaan Heidou for the relational analysis used,3 SSR loci were correlated with plant height trait,and 3 loci were correlated with plant height trait at low level.One low correlation loci were detected in the number of pod per plant,number of blighted pod and 100-seed weight.2 low correlation loci with seed weight per plant and 2 moderate correlation loci with seed color were detected.It is indicated that there are some gene loci associated with the main traits around these loci.Thus,the distance among the molecular markers can be decreased to lay the foundation for the molecular marker-assisted breeding of soybean.