Exploration of Genetic Variability of Bean (Phaseolus vulgaris L.) Landraces through ISSR Markers

In this study, 30 bean landraces collected from three Mexican states, namely Puebla, Zacatecas and Oaxaca, were evaluated in order to estimate genetic diversity among them through their genomic fingerprints obtained from ISSR (Inter Simple Sequence Repeat) markers. Genetic variability of semi-domesticated bean populations is a valuable resource for plant breeding programs as a source of stress-tolerant genes that were lost during the selection process of commercial cultivars. In this study, ten ISSR primers produced a total of 92 bands, 82 of which were polymorphic (representing 89 percent of polymorphism). Jaccard's distances between pairs of accessions were used to define four groups according to their molecular diversity. The results obtained from this study proved the existence of important genetic variability among bean landraces collected at distinct geographical locations, establishing the basis for conservation and utilization of evaluated materials for breeding purposes. ISSR molecular markers were able to genetically differentiate bean accessions despite their expected high genetic homogeneity due to their self-pollinating nature.