QTL Mapping and Analysis of Traits Related to Pod Dehiscence in Soybean

Abstract

Pod dehiscence (Pod shattering) (PD) is an important reproductive trait in soybean, while this trait also causes major yield losses in the mechanically harvested soybeans. In this research, QTL mapping and correlation analysis of three related traits (PD trait (PDH), ratio of thickness to width (RTW) and days of full maturity (DFM)) were performeded in 112 strains of soybean recombinant inbred lines (RIL) population (JINF population) by using methods of composite interval mapping (CIM). The results showed that there was an extremely significant negative correlation between PDH and RTW (P=0.01, -0.960), a significant negative correlation between PDH and DFM (P=0.05, -0.740), and also a significant positive correlation between RTW and DFM (P=0.05, 0.867). The results of QTL mapping demonstrated that there was a major QTL controlling PD, designated as qPDH6-1, mapped on soybean molecular linkage group (LG) C2 (chromosome 6) between Sat_062 and Satt520 with a linkage distance of 3.1 cM. The LOD value was found to be 12.15, and about 49.44% of the total variance was accounted for. Total of 3 QTLs linked to DFM, designated as qDFM6-1 , qDFM6-2 and, qDFM18-1 , were examined by CIM. qDFM6-1 was found in the same marker region between Sat_062 and Satt520 as qPDH6-1 on LG C2 (Chromosome 6), with linkage distance of 7.2 cM , LOD value of 6.59, and 21.77% of total variance accountable. qDFM6-2 was also found on chromosome 6 in the region between Satt291 and Satt305 with linkage distance of 12.3 cM, LOD value of 2.85, and 9.74% of the total variance accounted for. qDFM18-1 was mapped on LG A2 (Chromosome 18) in the region between Satt217 and Satt130,with linkage distance of 0.6 cM, LOD value 2.81, and 7.74% of the total variance accounted for. 3 QTLs related to RTW were also identified, designated as qRTW11-1 , qRTW4-1 , and qRTW8-1 , which were mapped in the regions between the SSR markers Satt426 and Satt509 on LG 11, between Satt361 and Satt399 on LG 4 and between Satt187 and Satt377 on LG 8, with the corresponding linkage distances of 7.2 cM, 12.3 cM and 0.6 cM, LOD values 3.00, 2.77 and 2.14, and 9.03%, 8.20% and 7.02% of the total variance accounted for, respectively.