Detecting quantitative trait loci (QTLs) related to pod dehiscence is required for molecular marker-assisted selection for breeding new varieties with pod dehiscence resistance. In this study, we constructed a high-density genetic linkage map using 260 recombinant inbred lines derived from the cultivars of Heihe 43 (pod-indehiscent) (ZDD24325) and Heihe 18 (pod-dehiscent) (ZDD23620). The map contained 4953 SLAF markers spanning 1478.86 cM on 20 linkage groups with an average distance between adjacent markers of 0.53 cM. In total, six novel QTLs related to pod dehiscence were mapped using inclusive composite interval mapping, explaining 7.22–24.44% of the phenotypic variance across 3 years, including three stable QTLs (qPD01, qPD05-1 and qPD08-1), that had been validated by developing CAPS/dCAPS markers. Based on the SNP/Indel and significant differential expression analyses of two parents, seven genes were selected as candidate genes for future study. The high-density map, three stable QTLs and their molecular markers will be helpful for map-based cloning of pod dehiscence resistance genes and marker-assisted selection of pod dehiscence resistance in soybean breeding.
Figure 2: Distribution of SLAF markers and polymorphic SLAF markers on chromosomes. The abscissa is the length of the chromosome, and each yellow stripe represents a chromosome. The genomes were divided in units of 1 M. Different colors indicate the number of SLAFs, the color is deeper and the SLAFs are more. Darker regions in the figure are concentrated distributions of SLAF markers. The upper panel of the figure represents the distribution of the SLAF tag and the bottom panel of the figure represents the distribution of polymorphism of SLAF markers (with M as the unit).