DIVERSITY ARRAY TECHNOLOGY (DART) USED FOR MAPPING DROUGHT TOLERANCE IN COMMON BEAN

Abstract

Common bean (Phaseolus vulgaris L.) is an economically important crop principally in developing countries in Latin America, Africa and Asia. Drought is one of the main abiotic stresses worldwide and affects about 60% of the bean growing area. Advances in molecular marker technologies offer powerful methods to examine elationships between traits, generating a large volume of potentially useful information to help breeding programs. This study aimed to use the DArT (Diversity Arrays Technology) platform for common bean together with microsatellites (SSRs) and SNPs (Single Nucleotide Polymorphism) for mapping the AND 277 x SEA 5 population from CIAT (Colombia), and locating QTLs associated with drought tolerance. A total of 4,468 DArTs, 288 SNPs and 180 SSRs were used in genotyping. Phenotyping of the 105 inbred recombinant lines (RILs, F8 generation) was performed by evaluating 18 traits associated with drought tolerance using a completely randomized design with four replications, applying a terminal stress in the vegetative phase V3/V4. Five SSRs, 91 SNPs and 4,468 DARTs were used for QTL detection which was performed through Statistical Machine Learning (SML). Eighteen QTLs were identified for the non-irrigated treatment for vase experiment and 05 QTLs for rhizotron experiment. All QTLs detected under drought conditions had the SEA 5 parent allele. This study is important for genetic improvement not only for a better understanding of the genetic inheritance of such a complex trait as drought tolerance, as well as for finding molecular tools to be used for marker-assisted selection.