Molecular diversity and genetic variability of kernel tocopherols among maize inbreds possessing favourable haplotypes of γ-tocopherol methyl transferase (ZmVTE4)

Vitamin E deficiency is a serious health concern in humans. Biofortification of maize kernel with high vitamin E (alpha-tocopherol) provides sustainable and cost-effective solution. Here, a set of 24 inbreds possessing favourable alleles of gamma-tocopherol methyl transferase (ZmVTE4) was analyzed. Significant variation for alpha-tocopherol (10.08-32.74 mu g/g), gamma-tocopherol (4.80-53.09 mu g/g), delta-tocopherol (1.06-11.89 mu g/g) and total tocopherol (20.18-97.72 mu g/g) was observed. The mean alpha-tocopherol in the ZmVTE4-favourable genotypes was 20.23 mu g/g compared to 4.75 mu g/g in the unfavourable genotype. alpha-, gamma- and delta-tocopherol constituted 39%, 48% and 13% of the total tocopherols, respectively, among positive lines. Molecular characterization of 24 lines using 80 SSRs generated 217 alleles. Wide variation was observed for PIC (0.08-0.73), gene diversity (0.08-0.76), major allele frequency (0.33-0.96) and dissimilarity coefficient (0.37-0.77). Cluster diagram grouped the inbreds into three distinct clusters consistent with the lineage. The study identified a set of potential cross combinations to develop high yielding hybrids enriched with vitamin E, and map additional gene(s) affecting accumulation of alpha-tocopherol. This is the first report on biochemical- and molecular- characterization of sub-tropically adapted inbreds with ZmVTE4-favourable allele.