Article / Virome analysis of melon with yellowish symptoms reveals mixed infections of known and emerging viruses in Southern Italy

Kwak, M., Desbiez, C., Kil, E.-J., Parrella, G. (2025) Virome analysis of melon with yellowish symptoms reveals mixed infections of known and emerging viruses in Southern Italy. Phytopathologia Mediterranea 64, 585-596. https://doi.org/10.36253/phyto-16655

Résumé : New viruses and virus strains have emerged with increasing frequencies in cucurbit cropping systems, and surveillance for these pathogens requires effective techniques. Virus diversity was assessed in a melon leaf sample from one field in the Campania region of Southern Italy. Four viruses were identified in melon presenting yellowish symptoms, including: cucurbit chlorotic yellows virus (CCYV), cucumis melo endornavirus (CmEV), tomato leaf curl New Delhi virus (ToLCNDV), and cucurbit aphid-borne yellows virus (CABYV). De novo assemblies reconstructed near-complete genomes of these viruses, and using data available in GenBank, whole genome phylogenetic relationships were determined. Based on the HTS results, a virus survey was then carried out in the same melon field, using 108 symptomatic and non-symptomatic leaf samples and RT-PCR/PCR for specific virus detections. Results obtained confirmed presence of the four viruses, with incidences of 78% for CmEV, 78% for ToLCNDV, 69% for CCYV and 52% for CABYV in the field. Most samples had mixed infections, with from two to four viruses in individual samples. Multiple infections comprised 41% infected with CABYV + ToLCNDV + CCYV + CmEV, 28% with ToLCNDV + CCYV + CmEV, 9% with CABYV + ToLCNDV and 2 % of CMV+CABYV. ToLCNDV and CmEV were the most abundant virus detected. This record of CCYV and CmEV is the first for these two viruses in Italy, with CCYV detected with high incidence. CABYV also had high incidence compared to previous reports for this virus. Further research is required, including with other cucurbit hosts, to determine incidence of emerging virus complexes causing yellowing disease in melon.