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

Authors: McNeece, Brandon; GILLENWATER, JAY - North Carolina State University; LI, ZENGLU - University Of Georgia; Mian, Rouf

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/19/2021
Publication Date: 4/26/2021
Citation: McNeece, B.T., Gillenwater, J., Li, Z., Mian, R.M. 2021. Assessment of soybean test weight among genotypes, environments, agronomic and seed compositional traits. Agronomy Journal. https://doi.org/10.1002/agj2.20665.
DOI: https://doi.org/10.1002/agj2.20665

Interpretive Summary: Test weight of soybean is an economically important trait for soybean transportation, storage, and quality. The value of soybean [Glycine max (L.) Merr.] is dependent upon quantity (yield) and quality. Test weight (TW) is a bulk density measurement for grain quality evaluation. Higher TW grains are preferred for storage, transport, and export. Thus, soybean breeding should include 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 other traits used in soybean breeding. Three sets of breeding populations (BPs), two mapping populations (MPs) and five different high vs low seed protein near-isogenic lines populations (NILPs) differing in protein and oil concentrations were analyzed. The BPs and MPs had an average range of 3.5 kg 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). One-hundred seed weight (SDWT) had strong significant negative relationships with TW in one BP (NC17-2) and one MP (NC19-3). Better seed quality (SQ) had significant positive effects on TW in two BPs - NC17-1 and NC18. The seed protein concentration (SPC) were significantly positively correlated with TW in NC18, and most of the NILPs. Seed oil concentration (SOC) was significantly negatively correlated with TW in NC18, NC19-2, and NILPs. TW was generally positively correlated with good SQ and SPC, while it was negatively correlated with SDWT and SOC in this study. This study will help guiding future studies on soybean TW.

Technical Abstract: The value of soybean [Glycine max (L.) Merr.] is dependent upon quantity (yield) and quality. Test weight (TW) is a bulk density measurement for grain quality evaluation. Higher TW grains are preferred for storage, transport, and export. Thus, soybean breeding should include 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 other traits used in soybean breeding. Three sets of breeding populations (BPs), two mapping populations (MPs) and five different high vs low seed protein near-isogenic lines populations (NILPs) differing in protein and oil concentrations were analyzed. The BPs and MPs had an average range of 3.5 kg 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). One-hundred seed weight (SDWT) had strong significant negative relationships with TW in one BP (NC17-2) and one MP (NC19-3). Better seed quality (SQ) had significant positive effects on TW in two BPs - NC17-1 and NC18. The seed protein concentration (SPC) were significantly positively correlated with TW in NC18, and most of the NILPs. Seed oil concentration (SOC) was significantly negatively correlated with TW in NC18, NC19-2, and NILPs. TW was generally positively correlated with good SQ and SPC, while it was negatively correlated with SDWT and SOC in this study.