Effect of Genotype, Environment, and Genotype × Environment Interaction on Tocopherol Accumulation in Soybean Seed

Abstract

ABSTRACTSoybean seeds [Glycine max (L.) Merrill] are a major source of tocopherols that provide many human health benefits including decrease in lung cancer risk and osteoporosis. The objectives of this study were: (i) to determine the impact of genotype, environment, and genotype × environment on soybean seed tocopherols and (ii) to evaluate relationships between agronomic traits and tocopherols. Seventy‐nine recombinant inbred lines (RILs) from the cross OAC Bayfield × OAC Shire were grown in three field locations in southern Ontario, Canada, in 2009 and 2010. Agronomic and seed quality data were collected in each location. Significant differences (P < 0.001) for the α‐, γ‐, δ‐, and total tocopherol concentrations were found in the seed of RILs using combined ANOVA for 2009 and 2010. Of the two parental lines, OAC Bayfield accumulated more total tocopherol at most environments. Genotype, location, and year differences were significant as well as genotype × location, location × year, and line × year interactions. Broad‐sense heritability estimates were 0.38 for α‐, 0.47 for γ‐, and 0.35 for δ‐tocopherol. None of the agronomic traits were consistently correlated with any of the tocopherol components; however, oil and protein concentration were correlated to some tocopherols in some of the environments. The wide range in values for α‐, γ‐, δ‐, and total tocopherols among the RIL population that exceeded both parents provided evidence for transgressive segregation. Our results suggest that soybean producers should take locations and genotypes into account when growing soybean for enhanced tocopherol production.