Breeding Common Bean for Resistance to Diseases: A Review

Diseases cause severe losses (20-100%) to yield and quality of common bean (Phaseolus vulgaris L.) worldwide. Our objectives were to describe major bean disease problems in the Americas and review progress achieved in breeding for resistance. We also describe strategies to integrate genetic improvement for resistance to multiple diseases with cultivar development. Common bacterial blight, halo blight, and bacterial brown spot are the major bacterial diseases. Angular leaf spot, anthracnose, root rots, rust, and white mold are severe fungal diseases. Bean common mosaic virus (BCMV), Bean golden mosaic virus (BGMV), Bean golden yellow mosaic virus (BGYMV), and Beet curly top virus (BCTV) are important viral diseases. Breeding for resistance to one or two diseases at a time is emphasized. Backcross, pedigree, and bulk-pedigree methods of breeding are used. The use of molecular markers has gradually increased. Substantial progress has been made in breeding and genetics of resistance to most of these diseases; however, improvement in resistance to bacterial brown spot, halo blight, root rots, and web blight has been slow and localized. Furthermore, cultivars with high levels of resistance to one or more quantitatively inherited diseases (e.g., common bacterial blight and white mold) are rare. Breeding strategies for simultaneous and integrated genetic improvement of multiple qualitatively and quantitatively inherited resistances and cultivar development are briefly described.