Hop Latent Viroid in Cannabis

Hop latent viroid (HLVd) is a single-stranded, circular infectious RNA that is completely dependent on its host plant’s metabolism for replication. As the name suggests, HLVd occurs worldwide in hops, but it can also infect hop’s relative, cannabis. 

How does Hop Latent Viroid affect Cannabis and Hemp Plants?

HLVd won’t kill the plant or even cause obvious symptoms of infection (i.e., curling or yellowing leaves); however plants will show subtle symptoms. 

HLVd will greatly reduce the quality and quantity of the flower the infected plant produces.  During the vegetative stage, plants will grow shorter with smaller leaves and tighter node spacing. Flowering plants will have smaller looser buds with much fewer trichomes. One of our clients estimated that plants infected with HLVd had half the cannabinoid content of healthy plants.

How does Hop Latent Viroid spread?

HLVd is most commonly spread via infected pruning tools, which is why cultivators should always sterilize their equipment before starting work on a new plant. 

HLVd can also spread through cloning when cuttings are taken from an infected mother. And because symptoms of HLVd are not obvious, it can be hard to identify infected mother plants. This is especially true when infection occurs later in the plant’s development, since stunted growth will not be as apparent. 

How can Hop Latent Viroid be Controlled?

Although HLVd can be eliminated from a cannabis or hemp plant via tissue culture, it is a long and laborious process that should only be reserved for cultivars that are critical to you business.

As with most plant pathogens, prevention is key. Good sanitation practices will go a long way in preventing the spread of HLVd and all other plant pathogens. Use fresh gloves each time you handle a new plant and sterilize tools often. 

Cultivators should also screen mother plants with qPCR tests to make sure any cuttings that are taken will be virus free. Cultivators can also screen incoming clones with qPCR assays to make sure they are not introducing infected plants to their grow. 

Test for Hop Latent Viroid with PathoSEEK

Medicinal Genomics has developed a PathoSEEK® qPCR assay that can be used to screen plants for three common virus infections: Lettuce Chlorosis Virus, Hop Latent Viroid, and Cannabis Cryptic Virus. DNA can be extracted from infected fan leaves using SenSATIVAx® DNA Purification Kits, and the multiplex assay can be run on the Agilent AriaMX and BioRad CFX96. If you are looking for a lab to test for HLVD, you can fill out the form below and we will connect you with a partner lab in your area. 

Available Hop Latent Viroid Products

Item # Name Reactions
420507 PathoSEEK® Virus Multiplex Assay A Starter Bundle
(HLVd, LCV, and Cannabis Cryptic Virus)
200 Buy Now
420121 PathoSEEK® Virus Multiplex Detection Assay A
(HLVd, LCV, and Cannabis Cryptic Virus)
200 Buy Now
420123 PathoSEEK® Hops Latent Viroid Positive Control 60 Buy Now

Prefer to Outsource Testing?

Cultivators who don’t have enough volume, lab experience, or start-up cash to test plants in-house can outsource to one of our partner labs. Fill out the form below and we will connect you with one in your area, if available.