Aphid‐borne viruses infecting cultivated watermelon and squash in Spain: Characterization of a variant of cucurbit aphid‐borne yellows virus (CABYV)

Aphid-borne viruses are responsible for major cucurbit diseases and hamper the sustainability of crop production. Systematic monitoring can reveal occurrence distribution these viruses, in addition to unadvertised facilitating control diseases. For three consecutive (2018–2020) seasons, presence aphid-borne was monitored from a total 292 samples watermelon squash plants that showed yellowing symptoms cucurbit-producing areas (Castilla La-Mancha, Alicante, Murcia) Spain. We observed yellows virus (CABYV) most common found (29%) both crops. Likewise, except Castilla La-Mancha mosaic (WMV) also (23%) with relatively high frequency. Furthermore, we exacerbation bright often accompanied by considerable fruit abortion. CABYV only causative agent this new disease, two infectious cDNA clones (one watermelon, CABYV-LP63, another melon, CABYV-MEC12.1) were constructed further compare characterize disease. Based on full-length genome, isolates grouped phylogenetically together within Mediterranean clade. However, Koch's postulates tests successfully completed LP63 isolate, which several amino acid changes potential recombination events, as compared MEC12.1. Remarkably, isolate caused more severe higher RNA accumulation than MEC12.1 five plant species. These results suggest novel variant causes may be causing outbreaks