Watermelon, a new host for Chickpea chlorotic dwarf virus

Watermelon (Citrullus lanatus) plants showing mild curling and size reduction of young leaves, and ripe fruits exhibiting chlorotic mottling on rind, white hard portions inside the flesh and unpleasant taste, were observed in different areas of Tunisia during several growing seasons (years 2005 to 2015). Leaves, fruit rind and fruit flesh were collected and total DNA was extracted. Rolling-circle amplification (RCA) using ?29 DNA polymerase was performed from a few representative samples. Several restriction enzymes were tested on the amplified DNA and a single DNA fragment of about 2500 bp was obtained following SpeI digestion from three different samples. The SpeI-restricted DNA molecule was cloned in pBluescript KS(+) and fully sequenced on both strands. The newly cloned DNA was 2571 nucleotides long and showed a typical Mastrevirus genomic organization. Sequence alignment analysis by BLASTN showed high nucleotide sequence identity values with several isolates of Chickpea chlorotic dwarf virus (CpCDV). Specific primers are currently used to test incidence of CpCDV infection in watermelon in Tunisia. Data regarding CpCDV infection in watermelon and association with the "hard watermelon syndrome" will be presented and discussed