First report of Moroccan watermelon mosaic virus in zucchini in Iran

During November 2017, 12 samples were collected from cucumbers (Cucumis sativus) and 14 from zucchini (Cucurbita pepo) plants grown in open field and showing virus-like symptoms such as mosaic, mottling, leaf deformation and yellowing leaf symptoms in Kerman province in South of Iran. The majority of both plant species were heavily infested by Bemisia tabaci, whereas no aphid colonies were observed. Leaf samples were collected from symptomatic plants and were subjected to total RNA extraction (Chatzinasiou et al., 2010). RT-PCR assays used for the detection of CCYV, CYSDV and CABYV (Orfanidou et al, 2014) showed that all samples were found positive to CABYV infection (26/26), whereas three cucumber samples were infected by CCYV (3/12) and four by CYSDV (4/12). Moreover, DAS-ELISA was used for detection of WMV, ZYMV, PRSV and Moroccan watermelon mosaic virus (MWMV) using polyclonal antisera kindly provided by Lecoq (INRA, France). None of the samples (0/26) was found to be infected with WMV, ZYMV or PRSV; however, 9 out of 14 zucchini samples were positive to MWMV infection. For further confirmation, specific primers namely MoDetF/MoDetR (5'-AARGAYGTTGATGTTGGRAC-3'/5'-CCATARTCAYTCTTGACYCCATC-3') were used to amplify a 211bp product of the Capsid Protein (CP) gene of MWMV. Results confirmed the presence of the virus in 9 out of 14 zucchini plants. Two isolates were selected for sequencing analysis and the BLASTn algorithm of the obtained sequences (accession numbers ..) showed 100% nucleotide identity with a MWMV isolate from Tunisia (Accession number EF579955). To our knowledge, this is the first report of MWMV infecting zucchini in Iran. Further surveys should concentrate on the spread, incidence and epidemiology of this virus and also other viruses infecting cucurbits in Iran.