Hop latent viroid

Hop latent viroid
Virus classification
(unranked):	Viroid
Family:	Pospiviroidae
Genus:	Cocadviroid
Species:	Hop latent viroid

Hop latent viroid (HpLV), formerly known as Dudding Disease, is a plant pathogenic virus. It is a non-capsulated strand of RNA and an obligate parasite that requires the presence of a compatible host for its survivability. It infects hemp and cannabis, and due to its ability to remain undetected, it has become an issue of significant risk for these cultivars. Studies regarding this viroid and its ability to infiltrate its plant host are well underway; however, addressing measures to reduce its introduction into growing environments is still challenging.

Transmission

Hop latent viroid most notably spread from performing mechanical practices with contaminated tools and equipment such as boots, shears, shovels, or tractors. Viroids cannot physically enter a host independently, requiring some vector; in this case, it is with unsterilized tools or equipment when managing cultivars. Propagules can be unintentionally infected when obtaining them from a mother plant, or they can be from an infected plant that is asymptomatic. Hop latent viroid can enter cultivars undetected since some plants don't demonstrate any signs of infection.

Effects on plant

Plants affected by hop latent viroid may display stunted growth, brittle stems, and reduced foliage; symptoms result from RNA of the viroid disrupting the plant metabolites. These symptoms are reflected in the plant's foliage as trichome development becomes uneven and leaves develop chlorosis. Unfortunately, there are no signs to pre-diagnose the viroid-infected plant, so the plant's physiology and yield quality are indicators.

Management

Critical practices in managing hop latent viroid involve narrowing down the viroid-infected plant before introducing it to a growing environment. Cannabis and hemp are grown from propagules obtained from a mother plant; verifying if the mother plant is diseased is essential to avoid propagating that plant. This process could be accomplished by isolating it in a different environment or testing it with available testing kits for the viroid. Monitoring the plant's development (height and foliage) and identifying any abnormalities could indicate the presence of the viroid (for newly introduced plants). However, as previously mentioned, the viroid can go undetected, and growing these plants require mechanical practices. Tools for any conducted procedure must be carefully sanitized with a solution of 10% bleach to kill off hop-latent viroid (if potentially present) before and after usage.

External sources

• ICTVdB - The Universal Virus Database: Hop latent virus
• Family Groups - The Baltimore Method
• "Hop Latent Viroid Detection Kits". PCR KIT Bioingentech.
• Dorantes, Oscar Armando (June 2021). "Fool's Gold: Diseased Marijuana and Cannabis Hyperemesis Syndrome". J Investig Med. 69 (5): 1063–1064. doi:10.1136/jim-2021-001980. PMC 8223652. PMID 34074707.
• "Hop Latent Viroid in Cannabis". Medicinal Genomics, 4 Mar. 2023
• "Hop Latent Viroid Information". Kaizen Horticulture.
• Scheck, Heather. "Hop Latent Viroid". Pest Rating Proposals and Final Ratings, 29 Apr. 2022.
• Wilson, Tim. "The Hop Latent Viroid's Warning Shot to the Canadian Cannabis Industry". StratCann, 1 Apr. 2021.