Browsing by Author "Yanda, Focus Edson"

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    Microsatellite analysis of common bean (Phaseolus vulgaris L.) genotypes in Tanzania for diversity in seed iron and zinc micronutrients
    (Greener Journal of Plant breeding and Crop Science, 2023-02-15) Yanda, Focus Edson; Tryphone, George Muhamba
    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.
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    Variability of common bean (Phaseolus vulgaris L.) in Tanzania as evidenced by morphological assessment
    (Greener Journal of Agricultural Sciences, 2022) Yanda, Focus Edson; Tryphone, George Muhamba
    A total of 84 common bean (Phaseolus vulgaris L.) accessions were collected from different areas of Tanzania serving as source of germplasm. Nineteen agromorphological traits of 84 common bean accessions were assessed to analyze the variability as a core objective for this study. Among all the accessions, 40.48% were characterized by indeterminate bush with moderate climbing ability and pods distributed evenly up to the plant habitus followed by 36.9%. Similarly, 14.29% were the genotypes with indeterminate bush with semi-climbing main stem and branches habitus genotypes. Also, 14.29% were the genotypes with the indeterminate bush with prostrate, and 7.14% were the genotypes with indeterminate bush with erect branches habitus while 1.19% were the genotypes with determinate bush least. Phonological, quantitative and qualitative traits were evaluated and their scores were subjected to principal component analysis and cluster analysis. The phylogenetic tree demonstrated 2 major clusters which were further divided into sub-clusters. Principal component analysis accounted for the accumulative variance of 35.78% revealing morphological variation highly attributed with variables which had greater than 0.2 Eigen values. The study demonstrated low morphological variation among the genotypes and emphasized the need to broaden genetic variability of the common bean in Tanzania. The results of this study can be used to select the valuable breeding material for use. Besides, molecular markers can be deployed to assess further the variability and diversity of these genotypes.