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ARS Home » Pacific West Area » Pullman, Washington » Grain Legume Genetics Physiology Research » Research » Publications at this Location » Publication #426641
Research Project: Enhancing Yield, Disease Resistance, and Agronomic Performance in Edible Legumes

Location: Grain Legume Genetics Physiology Research

Title: Snap bean diversity for resistance to bean common mosaic and necrosis viruses examined using new and existing candidate gene-linked markers

Author
item SOLER-GARZON, ALVARO - Washington State University
item HART, JOHN - Consultant
item Miklas, Phillip

Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/2025
Publication Date: 11/27/2025
Citation: Soler-Garzon, A., Hart, J., Miklas, P.N. 2025. Snap bean diversity for resistance to bean common mosaic and necrosis viruses examined using new and existing candidate gene-linked markers. Molecular Breeding. 45:98. https://doi.org/10.1007/s11032-025-01605-w.
DOI: https://doi.org/10.1007/s11032-025-01605-w

Interpretive Summary: Bean common mosaic and necrosis viruses (BCMV/BCMNV) plague snap bean production in the United States and worldwide. Genetic resistance provides the best control of this viral disease. Many genes interact to confer resistance. Herein we describe 26 resistance gene combinations present in a panel of 376 snap bean accessions primarly from the United States. The presence or absence of seven resistance genes contributes to the diversity of resistance observed. Several snap beans with exceptional combinations of resistance to combat these viruses were identified. These resistant snap beans combined with new and exisiting markers developed to identify and track the different resistance gene combinations provide an invaluable resource for snap bean breeding and will lead to the development of new culitvars with better and more durable resistance to an entrenced viral disease problem in the U.S.

Technical Abstract: Snap bean (Phaseolus vulgaris L.), a nutrient-rich crop, is limited by Bean common mosaic virus (BCMV) and Bean common mosaic necrosis virus (BCMNV). To better understand the genetic basis of resistance, 376 snap bean accessions and 12 F2 populations were screened with US-6 [pathogroup (PG)-VII], NL-8 (PG-III), or NL-3 (PG-VI) strains and genotyped for the I, RNase H-Like 1, bc-1, and bc-3 alleles using existing candidate gene-linked markers. Two Vps4 genes associated with bc-u and bc-2 recessive alleles were re-sequenced to identify novel mutations. Two major allelic groups of bc-u missense mutations were identified: (bc-ua = bc-ud = bc-ug) and (bc-ur = bc-us), each interacting differently with bc-1 and bc-2 to confer strain-specific resistance or susceptibility to NL-3 and US-6. The new bc-2[IVT 7214] and existing bc-2[Robust] and bc-2[UI-111] nonsense mutations exhibited the same genetic effect across pathogroups, suggesting a single allele. Twenty-six gene combinations were found, 16 of which included the dominant I gene. Overall, 336 of 376 accessions carried I gene, of which 233 possessed the I + RNase H-Like 1C + bc-1 combination characteristic of host group (HG)-9 cultivars with restricted vein necrosis (VN) to NL-8. Importantly, 30 accessions possessed I + RNase H-Like 1C + bc-1 + bc-ua,d,or g, conferring VN to NL-3 strain, characteristic of HG-10 cultivars. This panel provides a valuable resource of resistance diversity to BCMV and BCMNV, which can be used in breeding programs with the markers described. The bc-2 and bc-3 alleles, found in only one or two accessions, offer untapped resistance potential.