Development and Evaluation of SNP Molecular Markers Associated With Zinc Concentrations In Dry Beans

Dry bean (Phaseolus vulgaris L.) seeds are a rich source of dietary zinc, especially for people consuming plant-based diets as the body needs to support the function of the reproductive, immune and endocrine systems. Zn transport and accumulation is a complex trait which is governed by genes of small effect. A study has been initiated with this regard to carry out the analysis of QTLs for zinc accumulation in seed across five studies based on individual projection of maps on chromosome 2 and 11 onto a consensus map. Then, confidence intervals of QTL location were combined and five meta-QTLs were identified and comparative genomics approach showed consistency in location of zinc transporters genes which were co-located within the five meta-QTLs. Co-location of meta-QTLs and genes involved in transport or regulation of zinc identified seven candidate genes which includes zinc ion biding, ZIP metal ion transport family, zinc induced facilitator (ZIF), basic-leucine zipper (bZIP), heavy metal atpase (HMA), vacuolar iron transporter (VIT) & heavy metal transport on chromosomes PV02, and PV11.To identify useful markers for seed Zn concentration, fifty SNP markers were designed in regions on chromosomes PV02 & PV11 as candidates for MAS seed Zn concentration & were tested in populations segregating for the QTL for the seed Zn. Among them, 9 were monomorphic and 19 were polymorphic on chromosome 2 and 22 were polymorphic on chromosome 11.The molecular markers (SNP) are currently being evaluated in three bean populations viz., 48 black beans, 15 genotypes from a Middle American Diversity Panel and 28 genotypes from Andean Diversity Panel. The study will help us in identifying superior genotypes rich in Zn content & will provide a benchmark for the future bean plant breeding programs the across globe.