Multi-Environment Evaluation and Genetic Characterisation of Common Bean Breeding Lines for Organic Farming Systems

It is recognised that one of the main causes for the relative low yields under organic conditions is the use of modern cultivars which are bred for high-input management systems. The work described here aimed to study and test possible breeding strategies to produce cultivars of common bean for organic agriculture. To this purpose, crosses between a traditional Italian landrace named “Gnocchetto” and a cultivar were carried out. The F1 plants obtained were either backcrossed or self-fertilised and the obtained materials subjected to selection for quality traits at different development stages. The resulting lines were tested under four different environmental conditions for three years in order to determine their potential performance. The resulting data were analysed using a Multi-Environment Trial Analysis (MET) approach and different visualisations of the GGE biplot were generated. Furthermore, to assess the level of genetic similarity, the lines were characterised using 25 Simple Sequence Repeat (SSR) molecular markers. Results showed that the breeding approach applied allowed to select lines with the same technological and agronomic characteristics as commercially available cultivars, but with different adaptation abilities that make them suitable for organic agriculture.