Cucumber green mottle mosaic virus (CGMMV) is a Tobamovirus in the Virgaviridae. It was first detected in England. It then spread gradually to more European countries and different parts of Asia, and recently to North America and Africa. In 2014, it was detected for the first time in Australia infecting watermelon in the Northern Territory (NT). In July 2016, leaf sample was collected from a continental cucumber plant with leaf mottle and distortion symptoms growing in a commercial plastic tunnel house at Geraldton, Western Australia (WA). Diagnostics involving electron microscopy, ELISA, PCR and Next generation sequencing (NGS) were used to identify the presence of CGMMV in this sample (isolate WA-1).
When NGS was completed on isolate WA-1 the complete genome obtained had 6423 nucleotides. When subjected to BLAST analysis, the closest genomic nucleotide identities were 99.56-99.1% to genomes from Canada, Israel and India. CGMMV isolates from the other WA locations were found to have similar identities to that from Geraldton.
Delimiting surveys in key cucurbit growing areas (Geraldton, Carnarvon, Kununurra and Perth) were done between July-December 2016 to determine the extent of CGGMV spread. These included commercial cucurbit farms (field and protected cropping), roadside verges (Cucurbitaceae weeds) and seedling nurseries. A total of 95 locations were surveyed involving 41 properties and 54 roadside sites. Over 14,000 leaf samples were tested by ELISA and PCR. Infection with CGMMV was widespread occurring in 16 locations near Kununurra, Carnarvon, Geraldton or Perth). CGMMV was detected in cucumber, rockmelon, honeydew and watermelon crops, and single cucurbitaceous native plant and naturalized weed species.
Information workshops were held in WA cucurbit growing areas to deliver CGMMV management and biosecurity information.
Kehoe MA, Jones RAC, Coutts BA. 2017. First complete genome sequence of Cucumber green mottle mosaic virus isolated from Australia. Genome Announc 5:e00036-17.