Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.
Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.
Using Tepary Beans to Improve the Common Bean’s Ability to Resist Abiotic and Biotic Constraints
The common bean (Phaseolus vulgaris) is one of the most worldwide consumed food legumes. Abiotic and biotic constraints negatively impact the common bean’s production. Nevertheless, a common bean-related species, the tepary bean (Phaseolus acutifolius), is known for its ability to resist abiotic and biotic constraints. This tepary bean’s valuable genetic variation could be used to improve the common bean. Here, I present the development of three interspecific bean lines that were used as parental bridge lines to cross tepary beans with common beans without the need for embryo rescue. We carried out whole-genome sequencing of these lines and identified their genomic introgressions. We found that these lines have large introgression blocks from P. parvifolius on multiple chromosomes, suggesting that these introgressions are likely the reason for their fertile hybridization with tepary beans. Then, I present a multi-environment trials study conducted to determine the adaptation of tepary beans to multiple climate and stress conditions and identify tepary beans for crossing with common beans. We identified tepary beans with broad and narrow adaptation to heat and drought conditions. Elite tepary beans found here were crossed with common beans. Then, we evaluated multiple interspecific common/tepary bean populations for drought and heat. We also conducted a genome-wide association study to identify genomic regions underlying the genetic response of the evaluated traits. We found that multiple interspecific lines have improved capacity to produce under drought and heat stress than their parental lines. We also found quantitative trait nucleotides associated with the phenotypic response of the genotypes evaluated. Finally, we created a biparental F2 tepary bean population to identify quantitative trait locus (QTL) associated with the resistance to bean rust and common bacterial blight fuscans. We found one major QTL associated with the resistance to bacterial blight fuscans on chromosome Pa.07 and one major QTL associated with the resistance to bean rust on chromosome Pa.10. None of these QTLs are reported in common beans.
Barrera Lemus, Santos, "Using Tepary Beans to Improve the Common Bean’s Ability to Resist Abiotic and Biotic Constraints" (2021). ETD collection for University of Nebraska - Lincoln. AAI28865047.