Genetic variability-, genotype × environment interactions- and combining ability-analyses of kernel tocopherols among maize genotypes possessing novel allele of γ-tocopherol methyl transferase (ZmVTE4)

Abstract

Deficiency of vitamin-E or tocopherol causes neurological disorders in humans. α-tocopherol possessing the highest vitamin-E activity is present in low concentration in maize kernel. Nine lines and four testers possessing favourable allele of ZmVTE4 that significantly enhances vitamin-E activity were used to generate 36 hybrid combinations. Significant variation was observed for α- (5.95–39.03 μg/g), γ- (11.69–50.82 μg/g), δ- (4.09–10.76 μg/g) and total-tocopherol (33.18–90.53 μg/g). α-, γ- and δ-tocopherol constituted 36%, 53% and 11% of the total tocopherol, respectively. Majority of the experimental hybrids possessed significantly higher α-tocopherol (mean: 21.37 μg/g) than the check hybrids (mean: 11.16 μg/g). AMMI analysis revealed that across tocopherols, genotype and interaction effect accounted 35–77% and 23–45% of variation, respectively. The environmental effects were of minor magnitude. Non-additive gene action was predominant for α-, γ-, and total-tocopherol, while δ-tocopherol was conditioned predominantly by additive gene action. The information generated here assumes great significance in biofortification programme. This is the first report of variability, G × E interactions and combining ability for kernel tocopherol using maize hybrids possessing novel allele of ZmVTE4.