CGMMV and Its Effects
CGMMV is a member of the Tobamovirus genus which has long been a formidable adversary in the world of cucurbit cultivation, affecting crops like cucumbers, muskmelons, and watermelons worldwide. CGMMV is a serious problem for cucumber growers. Yield losses range between 25-50% when infection occurs at an early stage of the growing cycle.
Infected cucumber plants may also wilt and die prematurely, therefore are generally unmarketable. CGMMV infection causes structural changes in infected tissues leading to the mottling of leaves and fruits, and stunting of plants leading to reduced biomass. Early symptoms include vein clearing and crumpling on young leaves while mature leaves become bleached and chlorotic.
The virus can spread easily and stay alive for an extended time in plant debris, soil, water, vehicles, equipment, and tools. Contaminated seed and soil are the most common ways to introduce the virus into a crop. Regular handling of infected plants, such as when pruning or staking, can speed up the spread of the virus. One infected plant can infect up to ten healthy plants during these operations.
There is no cure for CGMMV, therefore the most effective means of control is prevention and monitoring measures such as certified seeds from reputable suppliers, healthy seedlings from reputable nurseries, regularly checking the farm, and reporting any unusual or unfamiliar symptoms.
Proof of Concept for RNA Based Treatment
This trial was conducted at the Agricultural Research Organization (ARO) – Volcani Center, Israel.
The objective was to determine the efficacy of the RNAway based treatment against CGMMV in mitigating the virus and severity of disease symptoms.
Trial design
Included 3 treatment groups: healthy plants, infected plants untreated, and infected plants treated with the RNAway based treatment.
A single RNAway based treatment was applied with irrigation, and plants were inoculated with the virus after 3 days.
Disease Assessment
The severity of CGMMV symptoms were qualitatively evaluated using the following categories: Size Color Bumps
Size = Reduction in new leaf biomass
Color = Degree of chlorosis
Bumps = Degree of leaf surface distortion
Each category was graded on a scale of 0-4, where a total score of 0 is completely healthy and 12 is severely symptomatic and / or collapsed from wilt.
Data presents plants treated with the RNAway based treatment remained healthy from the onset of disease incidence up to 25 days post inoculation with just a single irrigation treatment. Molecular testing (ELISA) also verified the absence of the virus in the irrigated RNAway treatment group.
Visual disease assessment 25 days post inoculation
Disease severity 25 days post inoculation
ELISA results 25 days post inoculation
