Prevalence of new and invasive geminiviruses and beta-satellites in plants: an extensive survey in Southern Italy on vegetables in the frame of GeMed, a research project involving five Mediterranean countries

Viruses represent serious threats to crop plants. They are responsible for a considerable decrease in yield, quality, and safety of crops and food security, with social repercussions all over the world. The main objective of the GeMed project is the prevention and control of new and invasive geminiviruses (NIGs) infecting vegetable crops in the Mediterranean area. Mono- or bipartite geminiviruses, are among the most worrying viruses due to their economic impact and their high propensity to recombine. A serious NIG, spread in the Mediterranean area, is tomato leaf curl New Delhi virus (ToLCNDV, Begomovirus), that, after its first detection in 2012 in Spain, progressively extended its geographic range to Tunisia, Italy and Morocco. Likewise, other geminiviruses, so far restricted to some Mediterranean areas, are expected to spread further: among the most dangerous, chickpea chlorotic dwarf virus (CpCDV, Mastrevirus), up to now reported only in North Africa, and squash leaf curl virus (SqLCV, Begomovirus) and watermelon chlorotic stunt virus (WmCSV, Begomovirus) restricted to eastern Mediterranean areas. Moreover, the presence of satellite molecules needs to be monitored as satellites can dramatically increase virulence. PRIMA project GeMed involves Italy, France, Jordan, Morocco and Tunisia. In Italy, surveys have been performed in two eco-agrosystems, Sicily and Campania during the 2020, 2021 and 2022 growing seasons. Symptomatic plants have been sampled in eighty-five different fields. Total nucleic acids have been extracted and specific PCR for each of the NIGs here considered and for beta-satellites were performed. The results of this survey will be presented.