Peanut antioxidants: Part 1. Genotypic variation and genotype-by-environment interaction in antioxidant capacity of raw kernels

•Genotypic variation of antioxidant capacity was studied in 32 representative Australian peanut genotypes.•G × E interaction was studied in 10 genotypes grown at 5 environments in 2 seasons.•Antioxidant capacity had significant variation of >25% relative standard deviation.•Genotype, environment, and G × E interaction were all significant (P < 0.05).•Antioxidant capacity was moderately heritable.

The potential to select for antioxidant traits in peanut (Arachis hypogaea L.) kernels by conventional plant breeding was investigated by oxygen radical absorbance capacity (ORAC) assay of (a) 32 full-season maturity genotypes grown at Kairi Research Station in 2008/09; and (b) a subset of ten genotypes with diverse antioxidant capacities grown in five different production regions in Queensland in 2009/10 and 2010/11. There were significant levels of variation of more than 25% relative standard deviation (RSD) in antioxidant capacity among the 32 tested genotypes; and that genotype, environment, and genotype-by-environment (G × E) interaction all significantly (P < 0.05) affected trait expression. Analysis of the G × E data confirmed the heritability of antioxidant capacity, which has not been previously quantified, whereby genotype explained 44% of the phenotypic variation on a plot basis and 82% on an entry mean basis. This indicated that there was substantial genetic control of antioxidant capacity in peanut kernels, but also that it will be important to characterize environmental interaction to enable plant/seed selection in the Breeding Program. The research also highlighted the utility of the ORAC assay for screening germplasm and provided practical advice on design of varietal assessments using antioxidant screenings.