An RNase H‐Like gene complements resistance to Bean common mosaic necrosis virus in Phaseolus vulgaris

Abstract

Abstract Bean common mosaic virus and Bean common mosaic necrosis virus (BCMNV) are related positive‐sense RNA potyviruses that limit the production of common bean (Phaseolus vulgaris L.) worldwide. Potyviruses infect other legume species, such as Glycine max, which can serve as a source of orthologous resistance genes. The bc‐1 on chromosome Pv03 in P. vulgaris and Rsv4 on Gm02 in G. max are syntenic gene regions that confer resistance to Potyviruses. Receptor‐like kinases underlie both gene regions, and a linked RNase H‐Like protein, which enhances potyvirus resistance, was recently associated with Rsv4. We sought to determine if RNase H‐Like encoding genes are similarly located in the bc‐1 region and enhance resistance to BCMNV. Synteny analysis between P. vulgaris and G. max revealed RNase H‐Like genes near the bc‐1 locus. Positional cloning among reference genomes and select genotypes, along with linkage mapping in recombinant inbred line and F2 populations, identified the RNase H‐Like 1 gene, which enhanced resistance to BCMNV NL‐3 strain when combined with I, bc‐1, and bc‐u or with bc‐1 and bc‐u genes by reducing systemic spread of susceptible symptoms in non‐inoculated leaves. A single nucleotide polymorphism marker, G03_4166082, was developed to track the resistant and susceptible alleles for RNase H‐Like 1 in breeding programs. Overall, this study advances the understanding of the complex mechanisms underlying BCMNV resistance in common bean.