Identification Of QTL Related To The Vertical Distribution Pod Number In Soybean

The number of pods is an important trait associated with soybean production and therefore has become an important breeding target.In order to explore new QTL(QTL,Quantitative trait locus)that can increase soybean production and cultivate high quality varieties,in this study,QTL mapping was performed using soybean-associated recombinant inbred lines RIL3613 and RIL6013 which were constructed by Dongnong L13,Heihe 36 and Henong 60 RIL(Recombinant inbred lines)as experimental materials.The experiment was conducted in 2015 to investigate the amount number of one-seed pod,number of two-seed pod,number of three-seed pod and number of four-seed pod at the top,middle and bottom of each plant.A total of 16 pod characteristics were defined.SSR(Simple Sequence Repeats)genetic maps(150 RIL3613 markers,2849.54 cM total marker length,137 RIL6013 markers,and 1886.8 cM total map length)were used to perform QTL mapping using the Inclusive composite interval mapping,composition interval mapping,singles marker analysis method simultaneously.For gene loci that are mapped by more than two methods at the same time,a QTL for the main effect was defined.The results showed that 21 QTL controlling the number of traits were detected in RIL3613,explaining the phenotypic variation of 1.45-11.67%,including 3 QTL for number of one-seed pod on upper part,5 QTL for number of one-seed pod on middle part,2 QTL for number of one-seed pod on lower part,4 QTL for total number of pod containing one seed,2 QTL for number of two-seed pod on middle part,2 QTL for number of two-seed pod on lower part,5 QTL for number of four-seed pod on middle part,4 QTL for number of four-seed pod on lower part,3 QTL for total number of pod containing four seed.26 QTL for control traits were detected in RIL6013,explaining the phenotypic variation of 0.04-7.91%,including 7 QTL for number of one-seed pod on upper part,3 QTL for number of one-seed pod on middle part,5 QTL for number of one-seed pod on lower part,1 QTL for number of two-seed pod on middle part,1 QTL for total number of pod containing two seed,2 QTL for number of three-seed pod on middle part,3 QTL for number of two-seed pod on lower part,6 QTL for number of four-seed pod on upper part,9 QTL for number of four-seed pod on middle part,13 QTL for number of four-seed pod on lower part,8 QTL for total number of pod containing four seed.14 QTL and 21 QTL detected in two populations overlapped with QTL found in previous research.They are genetically stable genetic loci.There are 11 overlapping marker region regions in the RIL3613 and RIL6013 populations.The 19 QTLs(qPN-C1-1,qPN-C1-2,qPN-C2-1,qPN-C2-2qPN-D1a-1,qPN-D1a-2,qPN-D1b-3,qPN-D1b-1,qPN-D1b-2,qPN-G-3,qPN-G-1,qPN-I-1,qPN-I-3,qPN-I-2,qPN-L-1,qPN-L-3,qPN-L-1,qPN-L-4,qPN-O-1,qPN-O-2)associated with the above regions not only represent potential gene loci that affect the seed-set of pod number and number of pods but also have important implications for molecular breeding.