Unraveling the dynamics of host specificity and resistance responses to potato virus Y, and implications for crop management

Abstract Potato virus Y (PVY), a virus member of the family Potyviridae, poses a significant threat to global agriculture, affecting crops such as potato, tomato, pepper, and tobacco. Despite its economic importance, there remains a critical gap in understanding the dynamics of PVY-host interactions and the development of effective management strategies. This study aimed to comprehensively characterize PVY isolates from sweet pepper, potato, and tomato plants, elucidating their infectivity and adaptation across diverse host species and cultivars. Initially, using antigen-trapped ELISA, we determined the optimal detection timeframe and leaf sampling strategy for detection of PVY by serological assays, showing that some hosts require a minimum incubation period and leaf selection for a reliable virus detection. By comparing PVY isolates from distinct hosts, we demonstrate that the choice of the isolate is crucial for resistance evaluations. Additionally, inoculation trials across various plant species elucidated differences in infectivity and adaptation among PVY isolates. Resistance trials in commercial cultivars of tomato and pepper plants and wild Solanum spp. accessions revealed susceptibility across all tested materials, challenging previous assumptions of resistant cultivars and accessions. These findings underscore the urgency of addressing PVY spread and understanding host-virus interactions to identify resistant genotypes for commercial use and for breeding programs directed to PVY isolates present in Brazil.