Investigation of Virus and Viroid Diseases in Cucurbits

Cucurbita species are economically important vegetables, with Türkiye ranking second in the world for gherkin and cucumber production and sixth for pumpkin and squash production. However, diseases caused by viruses are a threat to global cucurbit production. Due to global warming, changes in agricultural practices, and advancements in virus detection, the number of viruses infecting cucurbits has significantly increased in recent years. In this study, to identify causal viruses (potyviruses and begomoviruses) and viroids (pospiviroids) that induced symptoms on cucurbits, leaves exhibiting virus-like symptoms were surveyed and collected from cultivation areas in Türkiye from July to September 2024, and subjected to detection of causal agents. A total of 150 plant samples were collected from three locations, with plants randomly selected and viral infection symptoms observed. RT-PCR assays for potyviruses identified watermelon mosaic virus (WMV) in 30 samples (20%), which included 11 snake melon, 3 pumpkin, and 16 zucchini samples. Additionally, PCR assays for pospiviroids successfully detected pepper chat fruit viroid (PCFVd) in six samples, including zucchini and snake melon. Amplified products of the expected size were sequenced and showed identities of over 95% with PCFVd isolates in NCBI. This study reports for the first time the identification of zucchini and snake melon as natural hosts of PCFVd.