Microsatellite Analysis of Common Bean (Phaseolus vulgaris L.) Genotypes in Tanzania for Diversity in Seed Iron and Zinc Micronutrients

Common bean (Phaseolus vulgaris L.) grain has big dietary role in supplying protein, energy, vitamins, dietary fibre and micronutrients for millions of people worldwide. In Tanzania, reports have shown existence of Fe and Zn micronutrient variabilities among the common bean genotypes. Eighty-four (84) genotypes were collected to study such variability by seed biochemical and leaf molecular marker analysis. The analyses revealed significant (p < 0.001) genetic variability for seed Zn and Fe nutrient contents. Highest seed Fe content was 118 ppm for genotype Kashiransoni and for seed Zn was 51.81 ppm for Imponzo 5 genotype (both were collected from NPGRC). With seven (7) SSR primers associated with Fe and Zn traits, genetic diversity was evaluated. A marker BM154 scored PIC value 0.967 mean while marker BM160 had a lowest PIC score of 0.899. Using an estimated genetic similarity value, two main clusters with sub clusters in the dendrogram were developed. To corroborate the UPGMA analysis results, a Principal Coordinate Analysis (PCoA) was performed and displayed outputs into scattered plot presentation. For Fe micronutrient improvement purposes, Inula was proposed to be crossed with Kashiransoni while Roba with Imponzo 5 for Zn micronutrient improvement. Selection was based on both concentrations of nutrients for each genotype and their genetic similarity distances