Pepino Mosaic Virus in Tomato: Challenges, Control Strategies, and Future Prospects for Resistance Breeding.

Pepino mosaic virus (PepMV) is a highly infectious potexvirus that poses a significant threat to tomato cultivation in greenhouses worldwide. The threat posed by this virus is attributed to by its genetic complexity, characterized by the presence of multiple genotypes in circulation, mixed infections, and ongoing genotype turnover. Surveys of wild Solanum species have identified promising sources of resistance; however, this resistance is often incomplete, manifesting as symptomless, yet virus-positive, plants. When resistance is identified, introgressing of these traits into elite backgrounds is frequently impeded by reproductive barriers and linkage drag. Consequently, there are currently no commercially available cultivars with durable resistance to PepMV. Current control measures rely on stringent hygiene practices, seed health protocols, and the use of mild isolate cross-protection, which can mitigate fruit symptoms when carefully genotype-matched and closely monitored. Looking forward, achieving durable control will likely require host-centered strategies. Loss-of-susceptibility mutations and RNA interference-based approaches have demonstrated strong potential in experimental studies. Future solutions may involve the integration of genome editing with RNA-based technologies, supported by regulatory harmonization and socioeconomic viability considerations.