Current status of Cucurbit aphid-borne yellows virus in some greenhouse and open field cucumber in Iran (Article in English)

Yellowing and thickening are the most prevalent viral symptoms on cucumber grown in the greenhouses and open fields in Iran. Surveys were conducted from 2010 to 2012 in the major cucumber growing areas in the nine provinces, targeting especially the greenhouse plantations. Cucumber leaf samples showing symptoms like Cucurbit aphid-borne yellows virus (CABYV, genus Polerovirus, family Luteoviridae) infection, were collected from greenhouse (n=439) and open field- grown cucumbers (n=106) and tested for the presence of CABYV by DAS-ELISA and RT-PCR methods. 44% and 43% of collected samples from the greenhouses and open fields were infected to CABYV, respectively. Furthermore, CABYV positive samples were tested for the simultaneous infection of Cucurbit chlorotic yellows virus (CCYV) and Cucurbit yellow stunting disorder virus (CYSDV). Mixed infections with either CCYV or CYSDV were also confirmed in 9.4% of the CABYV-infected samples. The CABYV and CCYV combination was more prevalent than CABYV and CYSDV combination. Strain-specific RT-PCR confirmed the presence of common strain (CABYV-C) in all tested samples. Nine Iranian CABYV isolates were partially sequenced and sequence analysis has confirmed their assignment to the CABYV-C strain. The phylogenetic analysis revealed that although belonging to the CABYV-C, the Iranian cucumber CABYV isolates clustered within this strain in two phylogenetically distinct subgroups which might have an independent origin and/or introduction in Iran. This work provides further information on the natural occurrence of CABYV in Iran, including yet unreported characterization of CABYV-C strain on cucumbers grown in greenhouses and fields.