Shoot-fresh-weight (SFW) is one of the parameters, used to estimate the total plant biomass yield in soybean. Understanding the genetic and molecular basis of SFW could help increase the total biomass production. In this particular study, we identified QTLs associated with SFW in a Recombinant Inbred Line (RIL) population derived from interspecific cross of PI483463 and Hutcheson. A total of 551 (535 SNP and 16 SSR) markers, were found to be polymorphic between the parental lines and were used to screen the RILs to develop the genetic map. Linkage analysis and QTL mapping were performed using with the software QTL IciMapping version 4.0, with the minimum LOD score of 3.0 and estimating the likelihood of a QTL and its corresponding effects at every 1cM. QTLs with LOD value > threshold LOD, as determined by 1000 permutation tests at p > 0.05 were considered as significant QTLs. The analysis identified a total of 5 QTLs associated with shoot fresh weight over two environments, with the phenotypic variation (PV) ranging from 6.34 to 21.32%, and the additive effect from -0.54 to 0.33. Among these QTLs, qFW1314_19_1 had the largest LOD scores, with PV of 21.32%. Interestingly, three QTLs, qFW2013_19_1, qFW2014_19_1, and qFW1314_19_1 identified on chromosome 19(L), showed negative additive effects, indicating the contribution from the wild parent PI483463. The QTLs identified in this study can be the targets to identify the candidate genes for the SFW and can help in developing cultivars with increased biomass potential.

Seed weight (SW), often expressed as 100-seed weight (HSW), is an important yield component in soybean and has been found to show positive correlation with seed yield. It is shown to behave as a quantitative trait controlled by many loci that are largely unclear. In this study, we represent the identification of chromosomal regions controlling the seed weight in soybean. We used a Recombinant Inbred Line (RIL) population, consisting of 188 lines derived from a cross of a wild soybean PI483463 (HSW: 0.85g) and a cultivated soybean cultivar Hutcheson (HSW: 14.05g) to identify the chromosomal regions controlling the SW trait. The population, along with parental samples and check, William82 (HSW: 21.2g) was grown for four years and phenotype data was recorded postharvest. A total of 535 SNP and 16 SSR markers, polymorphic between the parents were employed to genotype the RILs using Golden gate assay to develop the linkage map. Whole genome QTL scanning identified a total of 17 QTLs, spanning 10 chromosomes for the 100-seed weight. All these QTLs explained phenotypic variation (PV) in the range of 3.77 to 12.33%. Of the 17 QTLs, 2 QTLs qSWA1-1 and qSWD2-1, found to be the consistent QTLs, expressing in all the four environments. The QTL qSWD2-1 explained highest contribution to the total PV with 10.04 -12.23 %. The remaining 15 QTLs were identified in at least one environment with PV ranging up to 10.39%. The findings from this study will provide useful information to understand the genetic and molecular basis of SW and facilitate further genomic research leading to the yield improvements in soybean.