Marcadores moleculares SCAR para identificar fuentes de resistencia a enfermedades en frijol ayocote (Phaseolus coccineus)

In order to identify genes of resistance to four diseases that affect Phaseolus sp. [i.e, Common Bacterial Blight (CBB), Bean Common Mosaic Virus (BCMV), Bean Golden Mosaic Virus (BGMV) and angular leaf spot (ALS)], we amplified nine SCAR (Sequence Characterized Amplified Regions) markers: four linked to resistance to common blight, two for BCMV, two for BGMV and one for ALS. The genetic material included 16 ayocote bean (P. coccineus) populations collected from different locations at Veracruz and Puebla, Mexico. Populations from Veracruz showed greater number of SCARs for BGMV and ALS compared with populations from Puebla. The best P. coccineus populations were Jalapa, Veracruz and Acultzingo (Veracruz); Nauzontla, and Zacapoaxtla (Puebla). Cluster analysis separated the bean populations evaluated by geographical origin, but mainly by the presence of two of the nine amplified markers (SU91 and LG5). The study populations, mainly those of Veracruz, should be used in breeding programs to generate segregating populations with genetic resistance to the major diseases of beans in Mexico, since they showed high frequencies of SCARs.