Cucurbit chlorotic yellows virus, a crinivirus infecting Cannabis sativa plants

High cannabidiol-containing plants of Cannabis sativa (high-CBD) growing in farms in Israel displayed foliar symptoms of interveinal chlorosis and yellowing, brittleness and occasionally necrosis. These symptoms, which were more apparent in older leaves, resembled those caused by the crinivirus lettuce chlorosis virus (LCV). However, this virus was not detected by reverse transcription (RT)-PCR using specific primer sets. High-throughput sequencing of viral RNA extracted from symptomatic leaves revealed the presence of cucurbit chlorotic yellows virus (CCYV), a crinivirus in the Closteroviridae family. The complete viral genome sequence was obtained using RT-PCR followed by Sanger sequencing. The two CCYV RNA genomic segments shared 99.5%-99.85% nucleotide sequence identity with CCYV isolates from the GenBank. The virus was transmitted from symptomatic cannabis leaves to healthy plants of cannabis and Cucumis sativus 'King Star' (cucumber) by the whitefly Bemisia tabaci Middle Eastern Asia Minor 1 (MEAM1) species, causing disease symptoms identical to those of the donor plants. Cannabis-CCYV was also transmitted between infected cucumber plants and cannabis seedlings of unknown genotype. Severe disease symptoms of yellowing and leaf-edge necrosis were observed on high-CBD and high Delta(9)-tetrahydrocannabinol-containing (high-THC) flowering cannabis plants and were associated with mixed infections of LCV and CCYV. To the best of our knowledge, this is the first report of CCYV infecting C. sativa plants.