Diversity of Common Bean Landraces, Breeding Lines, and Varieties from Cuba

Abstract

ABSTRACTCuba is the largest island in the Caribbean Sea and has a long history of common bean (Phaseolus vulgaris L.) cultivation. The crop was introduced to the island along with immigration of Native American tribes both from the west and from the southeast of the Caribbean archipelago. This resulted in both the Andean and Mesoamerican genepools being present in Cuba since pre‐Colombian times and opportunities for genepool intermixing in this secondary center of diversity. Microsatellites or simple sequence repeats (SSRs) have been found to be ideal for evaluating introgression in common bean because of their high polymorphism per locus. Therefore, the goal of this study was to use 36 SSR markers to evaluate a collection of 210 common bean landraces and cultivars from Cuba to determine the genetic diversity and common bean population structure found in this part of the Caribbean. The Cuban germplasm was very clearly divided into a majority Mesoamerican group and a minority Andean group. Surprisingly, the level of introgression between the genepools was lower than has been observed in previous studies of germplasm from other secondary centers of diversity. The optimum number of populations was K = 2, and subgroups were not evident, suggesting that only one race of each genepool is found on the island. In conclusion, Cuban beans are most likely to be derived from race Mesoamerica and race Nueva Granada, with very little mixing from other races. The implications of these results on the breeding of common beans in Cuba is discussed.