| dc.description.abstract | Common bean (Phaseolus vulgaris L.) is the most produced legume in the U.S. and worldwide. Fusarium root rot (FRR) is a widespread soil-borne diseases causing up to 86% yield reduction in beans. Large-seeded cultivars are usually susceptible to root rot. Finding FRR resistant genotypes under naturally infected soil and mapping genomic regions involved in its resistance were the main objectives in this research. In addition, halo blight, days to flower, growth habit, plant survival, seed weight, and seed yield were studied. Fusarium root rot and halo blight diseases were highly epidemic during the research period. The objectives were accomplished through two consecutive steps. First, phenotyping a set of genotypes from Andean diversity panel (ADP) under field conditions during three years starting with 310 genotypes in 2013. A Randomized Incomplete Block Design with two replications was used as the experimental design. From three years phenotypic data, ADP462-PI527540B, ADP48-W6_6534, ADP624-Dolly, ADP68-Soya, and ADP438-46_1 genotypes were resistant to FRR and ADP73-Masusu, ADP601-Camelot, ADP636-Montcalm, and ADP511-Canario were susceptible. In addition, ADP84-Kablanketi-defu, ADP55-Kabuku, ADP122-Kranskop, ADP454-INIAP429, and ADP50-Salunde were among the most resistant to halo blight and ADP638-Redhawk, ADP676-CELRK, ADP677-Etna, ADP242-G9013, and ADP269-G13092 were among the most susceptible. Genotypes ADP48-W6_6534, ADP624-Dolly, ADP438-46_1, and VAX3 (check) were resistant to both diseases. These genotypes can be used as parents in the bean breeding programs. Second, for GWAS, 3525 filtered single nucleotide polymorphism (SNP) markers of 246 Andean genotypes were used to find significant (P≤0.001) trait-marker associations. After correcting for population structure and relatedness, genomic regions on three chromosomes were associated with five traits. The study provided insights into the genetic architecture for FRR, halo blight, days to flower, growth habit and plant survival. Resistant genotypes can be used in the breeding programs, genomic regions should be validated before using as molecular markers to accelerate the breeding process. | en_US |
