Investigations on some yellowing viruses on cucumber, squash andmelon grown in greenhouse in Antalya

This study was carried out in order to diagnose yellowing viruses which are common in recent years and mixed with nutrient deficiency intensively cultivated cucumber, squash and melon production areas in Antalya province and its districts. During the surveys carried out in 2015-2016 in the production areas, severe and widespread yellowing symptoms were observed, especially chlorotic spots in the old leaves, chloroticisation in the interatomic areas, leaves with thick and fragile appearance, color opening in the veins and yellowing. For this reason, the presence of Kabakgil aphid-borne virus (Cucurbit aphid-borne yellow virus, CABYV), Cucurbit chlorotic yellows virus (CCYV) and Cucurbit yellow stunting disorder virus (CYSDV) was determined by serological and molecular methods. 89% of 460 suspected plant species which collected from cucumber, squash and melon plants were contamined with at least one of these three viral agents, were determined by DAS-ELISA and TAS-ELISA tests. The species identified by ELISA tests as single infection with CABYV, CCYV and CYSDV were confirmed by reverse transcription polymerase chain reaction (RT-PCR). The coat protein (CP) gene region was used for the diagnosis of CABYV and CCYV and the primers obtained from the heat shock protein gene region (Hsp70) for CYSDV were used in RT-PCR studies and the expected levels of band were obtained for all three viruses. RT-PCR products were used to determine the coat protein gene for CABYV and CCYV and the DNA sequences of the heat shock protein gene region for CYSDV. The DNA sequences obtained were compared with the CP and Hsp70 genes obtained from the different production regions of the world and registered in the GenBank, and the similarities and phylogenetic relationships of the isolates with each other and with other world isolates were revealed. CABYV isolates that found in the gene bank database were found to have similarities between the coat protein gene regions of the CABYV isolates is %96-100, and between 91-95% of the coat protein gene regions of the CCYV isolates. There was a 91-100% similarity between the hsp70h gene sequences of CYSDV isolates. CABYV, CCYV and CYSDV isolates were registered to gene bank with accession number of respectively MK129536, MK12953, MK129538.