Resistance to Infection by Fungal, Bacterial, and Viral Pathogens in a Common Bean Core Collection from the Iberian Peninsula

Abstract

Availability of germplasm with high level of resistance is essential for broadening the genetic base and breeding crop cultivars resistant to abiotic and biotic stresses. The objective of this study was to determine reaction of a common bean core collection from the Iberian Peninsula to anthracnose, rust, common and halo blights, bean common mosaic virus (BCMV, a potyvirus) and bean common mosaic necrosis virus (BCMNV, a potyvirus) pathogens. Of 43 accessions evaluated, 14 large-seeded Andean type, seven small-seeded Middle American type and seven with intermediate characteristics or recombinant type between the two gene pools had resistant reaction to one or more diseases. Resistance to race 17 or 23 of anthracnose pathogen was present in 17 accessions and four accessions were resistant to both races. Resistance to race 38 or 53 of rust pathogen was shown by 22 accessions and five accessions were resistant to both races. All accessions were susceptible to common bacterial blight and 12 accessions had resistance to halo blight. Ten accessions showed resistance to BCMV, none to BCMNV, and two were variable to both viruses. Accessions such as PHA-0573 (pinto), PHA-0589 (marrow), PHA-0654 (favada pinto), and PHA-0706 (favada) showed resistance to two or more diseases. These accessions may be valuable in breeding Andean bean for enhancing simultaneous utilization of both large seed size and disease resistance.