Morphological and genetic diversity among and within common bean (Phaseolus vulgaris L.) landraces from the Campania region (Southern Italy).

The common bean (Phaseolus vulgaris L.) is arguably the most important food legume and a fundamentalsource of proteins especially for rural societies. In several countries, this species is characterized by anumber of locally adapted landraces and many of them are at risk of extinction. In Italy, common beancultivation has always been a typical element of rural economies especially in the Southern regions. Wecarried out an investigation of the morphological and genetic diversity in 25 common bean populationscultivated in the Campania region (Southern Italy). We analyzed 26 qualitative and 11 quantitativetraits following the IPGRI descriptors. Furthermore, 10 SSRs were employed to examine genetic poly-morphism, differentiation and population structure. Molecular and morphological data distinguished allthe landraces under investigation. A considerable phenotypic diversity among landraces was observedfor many characters, including some related to agronomical performance. At molecular level, all theSSRs were polymorphic, with an average of 8.5 alleles per locus. Moreover, the vast majority of thelandraces (92%) displayed intra-varietal differences. Our work indicated the presence of a wide-rangingvariation among and within cultivated common bean landraces. Moreover, it provided evidence thatthe implementation of measures for their on-farm conservation, management and promotion should beuseful also to preserve genetic variability.