Data from: Evaluation of host plant resistance to <i>Alfalfa mosaic virus</i> in peppers in greenhouse and field

<i>Alfalfa mosaic virus </i>(<i>Martellivirales: Bromoviridae</i>) (AMV) is an emerging pathogen of peppers (<i>Capsicum </i>spp. L.) in Colorado that has caused significant yield losses. The virus is transmitted non-persistently by aphids, and few management options are available to suppress the disease. Thus, the goal of this work was to evaluate the effectiveness of host plant resistance against AMV. We evaluated 30 commercially available pepper cultivars for resistance to AMV in the greenhouse and validated resistance in a subset of these under field conditions on commercial farms in Pueblo, CO. Plants were mechanically inoculated with AMV in the greenhouse, while peppers in the field were exposed to natural infection. Virus infection was assessed by quantifying symptom severity and measuring incidence through visual observations and ELISA. We found that in the greenhouse, 10% of cultivars showed no symptoms of AMV and low infection rates, indicating strong resistance, while an additional 25% displayed tolerance, with mild symptoms and reduced infection. Field trials on commercial farms revealed that half of the tested cultivars maintained low symptom severity and infection incidence throughout the season, though none exhibited complete resistance. Cultivar responses were consistent between greenhouse and field settings, and temporal changes in susceptibility were also observed in two cultivars. Our findings identify several pepper cultivars with innate resistance or tolerance to AMV that could be integrated into pest management programs. These results also provide a foundation for future research aimed at breeding AMV-resistant peppers and developing comprehensive management strategies for this emerging viral disease.