FIRST REPORT OF SQUASH MOSAIC VIRUS IN TURKEY

Widespread symptoms of a possible virus disease were repeatedly observed in melon crops (Cucumis melo) grown in the provinces of Mersin, Adana, and Urfa (south-west Turkey). Affected plants showed mild to chlorotic mottling of the leaves, deformation of the blades, and chlorotic patches on the fruits. A virus was consistenly recovered from symptomatic leaf samples from different areas by mechanical transmission to herbaceous hosts. Symptoms in inoculated melon seedlings were the same as those observed in the field. ELISA tests of leaf extracts from naturally and artificially infected melon plants gave positive reactions with two antisera to Squash mosaic virus (SqMV; genus Comovirus, family Comoviridae), supplied either by Dr. H. Lecoq (INRA, Montfavet, France) or a Turkish company (Lojistic). Since the seeds used to establish the crops had been imported from abroad and SqMV is known to be seed-borne, seeds from imported seed batches were obtained from the farms where the disease occurred. SqMV was consistently detected by ELISA in germinated seeds from all batches. SqMV has several strains for three of which (Kimble, Arizona and Melon) partial sequences are available. Strain-specific primers, designed by using Genbank sequences AF059533 (Kimble strain), AF059532 (Arizona strain), and M96148 (Melon strain), were used in PCR assays for amplifying reverse transcribed viral RNA extracted from diseased plants. Amplicons of the expected size (579 bp) were obtained only with primers specific to the Kimble strain. This is the first report of the occurrence of SqMV in Turkey, where it has probably been introduced with imported seeds.