Dry beans (Phaseolus vulgaris L.) are an important legume for human consumption worldwide, providing key dietary nutrients such as carbohydrates, protein, and fiber. Michigan is the second largest dry bean producer in the United States, producing over 400 million pounds of dry edible beans per year and contributing to a farm gate value of over $139 million. However, biotic stress caused by fungal disease infection is among the main constraints that limit yield and increase management cost of dry bean production. Two of the most devastating fungal diseases in Michigan are white mold and root rot, which can cause up to 80-100% yield and seed quality decline in susceptible cultivars under heavy disease pressure. Resistant breeding lines are the ideal solution to managing these diseases as chemical control is expensive, harmful to the environment, and doesn’t ensure complete protection against infection. Unfortunately, resistance to both diseases is controlled by complex quantitative inheritance methods, with a lack of large effect resistance genes, laborious screening protocols, and historic difficulty pyramiding genes into one durably resistant phenotype. Therefore this research aimed to assist dry bean breeders in developing resistant lines by i) evaluating genomic prediction and GP + de novo GWAS as a tool for white mold (Sclerotinia sclerotiorum) resistance screening, ii) evaluating a diverse set of lines for resistance to root rots conferred by Rhizoctonia solani and Fusarium oxysporum, iii) investigating correlations between Fusarium oxysporum inoculated field and greenhouse screens and natural infection conditions and, iiii) investigating correlations between Fusarium oxysporum root rot resistance and major agronomic/ aboveground traits as an alternative non-destructive, high-throughput phenotyping method. The findings from these studies will ultimately assist dry bean breeders in the development of resistant lines for these important diseases.
Read
