Molecular characterization and genetic variability of traditional common bean accessions

Brazil is an important center of secondary diversity for common beans, with a vast variability of germplasm. This food is the most consumed legume in Brazil and, for Espírito Santo, which is a state characterized by family-based agriculture, it is a good income option for farmers. Bean diversity is underestimated, despite its importance, making the collection and characterization of germplasm essential, especially due to the challenges faced by producers, such as environmental influences that lead to the loss of genotypes. This study aimed to estimate the genetic variability of common bean germplasm collected in the state of Espírito Santo through molecular characterization via ISSR-type markers. To this end, 67 common bean accessions were used. The accessions were planted in a greenhouse and after 45 days the leaves were collected for DNA extraction. For molecular analysis, 23 ISSR markers were used and for statistical analysis, a dissimilarity matrix was obtained based on the Jaccard index, and from this matrix the dendrogram was constructed. The results revealed 67 different accessions, with high polymorphism being found, which assertively highlights a high genetic variability. In the dendrogram, it was also possible to verify the separation of the beans according to the gene pools: Andean and Mesoamerican. In this way, it was possible to confirm the fundamental role of farmers in the conservation of common beans in the state, highlighting the high variability maintained by them and the importance of preserving this genetic heritage.