Molecular characterisation of wild populations and landraces of common bean from northwestern Argentina

Abstract

Information on the variability of wild bean populations and landraces is essential to set conservation strategies and design breeding programmes aimed at enlarging the genetic base of commercial beans. Nineteen Argentinean common bean landraces and wild populations were characterised and their diversity was analysed by means of inter-simple sequence repeat (ISSR) markers and seed proteins. Populations were successfully identified as belonging to the Andean gene pool of origin by phaseolin electrophoresis, whereas ISSR markers revealed high levels of inter and intra-population variability. Four of 10 primers produced polymorphic and reproducible DNA profiles, which were used to generate UPGMA (unweighted pair group method with arithmetical averages) and NJ (neighbour-joining) trees. ISSR markers revealed a high level of variability both within wild bean populations and landraces. Genetic variability of wild samples was associated with their geographic distribution. By contrast, landraces were clustered, at least to some degree, based on their seed colour and shape, showing no clear discrimination among sites. The results presented here suggest that, to a certain extent, hybridisation between wild beans and landraces occurs in the wild, a hypothesis that needs to be tested through further analyses.