Molecular and biological characterization of Watermelon chlorotic stunt virus (WmCSV): An Eastern Hemisphere begomovirus introduced in the Western Hemisphere

Watermelon chlorotic stunt virus (WmCSV) is a bipartite begomovirus that causes severe diseases to cucurbits, particularly watermelon, across Eastern Mediterranean countries. Watermelon plants showing begomovirus-associated symptoms and virus vector whitefly infestation were collected from a cultivated area in Sonora, Mexico. Using rolling circle amplification (RCA) and sequencing, the full-length genome of an isolate of WmCSV was obtained. Agrobacterium-mediated virus inoculation to Solanaceae (Nicotiana benthamiana and tomato) and Cucurbitaceae (Squash, melon and watermelon) plants, fulfilled Koch's postulates confirming the disease causal agent. To the best of our knowledge, this is the first report of WmCSV associated to cucurbit diseases in the Western Hemisphere.