First report of cucurbit aphid-borne yellows virus in Cucurbita pepo and Cucurbita maxima in Slovenia.
In summer of 2017 and 2018, a survey was conducted in the major cucurbit-growing areas in Slovenia to assess the occurrence of viral diseases. Leaf samples of 20 plants of Cucurbita pepo, three Cucurbita maxima, seven Cucumis melo, one Cucumis sativus, and one Citrullus lanatus showing mosaic, interveinal mottling or yellowing, blisters, and distortions were collected from 11 farms in southwestern Slovenia, seven in northeastern Slovenia, and five in southeastern Slovenia. Sequences of Cucurbit aphid-borne yellows virus (CABYV) were detected along with sequences of Cucumber mosaic virus (CMV), Watermelon mosaic virus (WMV), and/or Zucchini yellow mosaic virus (ZYMV). To confirm the presence of CABYV, each of the 26 individual plants, which were part of the pools of CABYV-positive samples, were tested by reverse transcription PCR using the coat protein (CP) gene-specific primers CE9/CE10. An amplicon of the expected size (600 bp) was generated from samples of 13 plants of C. pepo and from one of the C. maxima samples. CABYV is widespread throughout the Mediterranean Basin, but it was found for the first time in Slovenia in this study. The presence of CABYV in five different farms in southwestern Slovenia (eight samples) and in six different farms in northeastern Slovenia. Leaf yellowing symptoms were expressed on C. pepo infected by CABYV only. In some of the mixed infected plants, severe symptoms were observed.