FIRST REPORT OF CUCURBIT CHLOROTIC YELLOWS VIRUS IN CUCUMBER IN TURKEY

Abstract

In November 2015 and February 2016, yellowing symptoms were observed in three greenhouse-grown cucumber crops in Antalya recalling those induced by Beet pseudo-yellows virus (BPYV), Cucurbit yellow stunting disorder virus (CYSDV) and Cucurbit chlorotic yellows virus (CCYV). To investigate the etiology of the yellowing disease observed, leaves from 30 symptomatic plants were subjected to total RNA extraction and tested by RT-PCR for the presence of BPYV, CYSDV (Boubourakas et al., 2006), and CCYV (Orfanidou et al., 2014). Fifteen samples were found infected by CYSDV and 21 by CCYV, of which 6 plants were dually infected by CYSDV and CCYV. Since CYSDV was already known in Turkey, the partial RdRp region of 2 isolates of CCYV was sequenced (Orfanidou et al., 2014) and BLASTn analysis of the obtained sequences (accession Nos. LT577941, LT577942) showed 99% identity with a CCYV isolate from Japan (AB523788). Moreover, transmission experiments by Bemisia tabaci biotype Q (MED) were carried out. Five groups of 30 adult whiteflies were given an acquisition access time of 24 h on cucumber leaves naturally infected only with CCYV. Thereafter, each whitefly group was transferred onto a healthy cucumber plant (hybrid Galeon) for an inoculation access time of 72 h, and 3 weeks post inoculation CCYV was detected in 4 out of 5 inoculated plants by RT-PCR. To our knowledge, this is the first report of CCYV infecting cucumber in Turkey. CCYV has also been reported in Lebanon, Egypt and Greece thus indicating that it is an emerging pathogen of cucurbit crops in the Mediterranean region.