Cucumber green mottle mosaic virus (CGMMV) is a seed transmitted Tobamovirus that infects several cucurbit species and can result in significant crop losses. Recent findings of CGMMV in the United States and Australia have resulted in increased biosecurity measures for international seed trade. Most commonly, cucurbit seed is tested using ELISA and / or PCR to determine if it is contaminated with the pathogen. While ELISA and PCR are considered to be reliable testing methods, they are also laborious and take several hours to complete. In 2015 Agdia raised new monoclonal and polyclonal antibodies to CGMMV for the purpose of developing improved serological diagnostics that could be used for seed testing. One pair demonstrated superior sensitivity, particularly in a lateral flow device (ImmunoStrip®) format, and was selected for assay development. The resulting ImmunoStrip was found to be more sensitive than ELISA and demonstrated a high degree of specificity to CGMMV. It was hypothesized, based on its high degree of sensitivity, that the ImmunoStrip could offer a more sensitive method for detection of CGMMV in seed commodities. Such an assay could provide biosecurity personnel a mechanism to test seed lots in non-laboratory environments and obtain results hours faster than other methods currently in use.
To challenge this hypothesis several lots of infected seed were obtained that varied in CGMMV contamination levels. These lots were tested by the ImmunoStrip and compared to ELISA following International Seed Testing Association (ISTA) testing guidelines. The results, to be presented, provide compelling evidence the ImmunoStrip can be used for reliable detection of low level CGMMV contamination of cucurbit seed lots. To our knowledge this would be the first lateral flow test validated for detecting CGMMV in seed commodities.