Identificação e validação de regiões genômicas associadas às características agronômicas e doença no feijão comum

Abstract

To increase the competitiveness and efficiency of common bean production systems, it is important to identify and validate genomic regions associated with agronomically important traits. Among these traits, upright plant architecture, the number of days to flowering, and resistance to diseases, especially anthracnose, stand out. This strategy ensures the effective application of these markers in the context of marker-assisted selection genetic breeding, promoting significant advances in yield and grain quality. The objective of this study was to: 1) Perform association mapping for plant architecture and the number of days to the beginning of flowering. 2) Validate the previously identified SNP marker linked to the resistance allele to the Lv238 isolate of the race 65 of Colletotrichum lindemuthianum. To achieve the first objective, the association mapping approach was used, using a UFLA diversity panel with 121 lines genotyped with the BARCBEAN6K_Illumina SNP Chip with 5398 SNPs and phenotyped in the field in two seasons. For validation, for the SNP marker ss715646893 (1,165,722pb), an F2 population from the cross between the cultivars BRS Estilo x BRS Valente and a diversity panel with 49 lines were used from synthesis and genotyping with the TaqManTM probe. Resistance to the Lv238 isolate is controlled by a gene (R2 = 72%),

mapped in a region of chromosome Pv04 that has 17 repeat Kinase receptor proteins (LRR- RLK). The result of the association mapping identified 4 SNPs for upright plant architecture

and another 2 SNPs for the number of days to the beginning of flowering. These SNPs were identified on chromosomes Pv08 and Pv10. Regarding validation, the genotyping system based on TaqManTM type hydrolysis assays for the SNP marker ss715646893 was specific for the target allele CoL. The SNP marker ss715646893 presented a recombination frequency of 11.40% and a selection efficiency of 94.80% in the F2 population. The results obtained highlight the importance of identifying and validating molecular markers associated with target alleles for agronomic traits in common bean. This strategy is essential for the selection of parents and genotypes that present alleles of interest. There is an expectation of increased selection efficiency and genetic gain per unit of time in common bean breeding programs.