Identification, mapping of the genomic regions and mining of the candidate genes for Hundred Seed Weight (HSW) in soybean [Glycine max (L.) Merr.]

Abstract

Hundred seed weight (HSW) in soybean is an important trait determining yield and quality and is also desirable for specialty soy foods like tofu, natto, miso, and edamame. In order to identify the quantitative trait loci (QTLs) and mining of the candidate genes for HSW in soybean (Glycine max.), the current study was conducted on bold seeded soybean genotype EC1023 and VLS61, a medium seeded soybean genotypes derived F2 and F2:3 mapping populations. Genetic polymorphism studied with 517 SSR markers indicated the significant polymorphism between the parental genotypes to be 19.95% (103 markers); however, distribution of the polymorphism was not uniform across the chromosomes; Chr. 14 had 30.00 % polymorphism as against 7.14 % on Chrs.12. Through inclusive composite interval mapping approach, two major quantitative trait loci (QTLs) viz., qHSW-5.1 (PVE=10.70%) and qHSW-17.1 (PVE=19.86%) were mapped on Chr. 5 and Chr.17, respectively. The mapped QTLs were validated on interspecific RILs with varying level of HSW. QTL (qHSW-17.1) on Chr. 17 in the marker region Satt301-Sat_326 overlapped with the previously reported QTL for seed viability in soybean. Based on Protein Analysis Through Evolutionary Relationships (PANTHER), gene annotation information, andliterature search, 64 genes within two QTLs were predicted to be possible candidate genes that might regulate the HSW in soybean. The current study identified the two major QTLs and key candidate genes which govern the HSW in soybean, paving the way for developing soybean varieties with improved HSW through marker-assisted breeding.