Molecular characterization of elite maize (Zea mays L.) inbreds using markers associated with iron and zinc transporter genes

Traditional maize (Zea mays L.) is deficient in iron (Fe) and zinc (Zn). Metal transporter proteins play pivotal role in uptake, translocation and accumulation of minerals. Here, a set of 70 intergenic SSRs, 20 intragenic SSRs and 20 intragenic InDel markers encompassing 62 metal transporter genes were used for characterization of 24 diverse inbreds varying for Fe (13.95-37.34 mu g/g) and Zn (11.83-37.90 mu g/g). A total of 356 alleles, with 26 unique (7.03%) and 36 rare (10.11%) alleles were observed. Cluster analysis categorized the inbreds into two main clusters. Five candidate gene-based intragenic SSRs were significantly associated with Fe (r = 0.46-0.52). Two intragenic InDel markers and 11 SSRs were significantly correlated with Zn (r = 0.44-0.76). HUZM-185 and HKI-323 possessed favourable allele of five genes that showed significantly high correlation with Fe. At least six significantly associated genes for Zn were found in BQPML-5207-4-2, CML152, CML169 and HKI193-1. Based on genetic distance, presence of genes and high micronutrients, potential cross combinations were identified for the exploitation of heterosis. This study is the first report on characterizing maize inbreds using markers for metal transporter genes.