New sources of resistance to bacterial wilt identified in dry bean germplasm collection

Abstract

Objectives of the present investigation were to obtain preliminary knowledge on the variability of Curtobacterium flaccumfasciens pv. flaccumfasciens (Cff) and identify new sources of resistance to bacterial wilt of dry bean. Three isolates of Cff were inoculated on the cultivars Perola, Xamego, Rosinha G-2, Diamante Negro and Valente. Since the non-environmental variation was mainly affected by isolates and cultivars, the isolate Cff CNF 4 was selected to test dry bean genotypes for disease resistance due to its high degree of pathogenicity in a set of six cultivars. Of 333 tested accessions, 12 exhibited resistance reaction, while 85 plants showed both compatible and incompatible reactions to the pathogen. The resistant plants were selected and the families derived from these plants will be further tested to confirm the resistance reaction. The resist ant accessions and the selected ones that confirm the reaction class will be incorporated in the Embrapa Rice and Beans breeding program.