Assessment of soybean test weight among genotypes, environments, agronomic and seed compositional traits

Abstract

AbstractThe value of soybean [Glycine max (L.) Merr.] depends on quantity (yield) and quality, such as seed composition and test weight (TW). Test weight is a bulk density measurement for grain quality evaluation, and higher TW grains are preferred for storage, transport, and export. Thus, soybean breeding should focus on improvement of TW. The objectives of this study were to determine genotypic and environmental effects on TW of soybean and explore relationships of TW with yield, maturity, 100 seed weight (SDWT), seed quality (SQ), seed oil concentration (SOC), and seed protein concentration (SPC). Three sets of breeding populations (BPs), two mapping populations (MPs), and five different high vs. low seed protein near‐isogenic lines populations (NILPs) were used. The BPs and MPs had an average range of 3.5 kg hectoliter (hL)–1 in TW among genotypes. The average ranges of TW in the NILPs were equal for both low protein (LP) and high protein (HP) lines (2.7 kg hL–1). Broad‐sense heritability estimates for TW ranged from .62 to .95. The genotypic and G × E effects on TW were significant in all trials. The SDWT, SQ, SOC, and SPC had strong significant relationships with TW in multiple trials, but were inconsistent overall. Test weight of NILPs differing by presence of ‘Danbaekkong’ high protein allele on chromosome 20 had mostly significant positive and negative relationships with SPC and SOC, respectively.