Association of Tomato leaf curl Sudan virus with leaf curl disease of Squash in Saudi Arabia

During the field survey of cucurbits field in 2014–15, severe leaf curl disease of Squash was observed in the Kingdom of Saudi Arabia. The naturally infected plants exhibited typical upward severe leaf curling with stunted plant growth. The causative agent was identified by PCR using coat protein gene specific primers. Whiteflies were also observed in the cucurbits field indicated the possible begomovirus infection. An amplicon of 750 bp from naturally infected leaf samples was obtained which confirmed the association of a begomovirus with squash leaf curl disease. The full length betasatellites were also amplified from infected samples by using betasatellites specific primers. The rolling circle amplification was used to amplify the full viral genome. The full-length as well as betasatellites genomes were cloned and sequenced bidirectionally. The highest sequence identity (93.7%) of full genome was observed with Tomato leaf curl Sudan virus-Tomato-Hail isolates. The Phylogenetic tree analysis of full genome formed closed cluster with Tomato leaf curl Sudan virus -Tomato-Jeddah, Hadasham and Tabuk which provided the strong evidence about the association of Tomato leaf curl Sudan virus with squash leaf curl disease in Saudi Arabia.