Evaluation of hop varieties (Humulus lupulus L.) for their response to HLVd, HSVd, and CBCVd viroids in tissue cultures

Abstract This study evaluates the susceptibility of various hop varieties to three viroids: Hop Latent Viroid (HLVd), Hop Stunt Viroid (HSVd), and Citrus Bark Cracking Viroid (CBCVd), all of which pose significant threats to Slovenian hop production. The experiment was conducted under in vitro conditions, involving the cultivation of 13 different hop varieties in tissue cultures, alongside the in vitro synthesis of viroid transcripts and subsequent inoculation of the plants. The plants were then monitored for growth, development, and their responses to viroid infection. The findings reveal the complex interactions between hops and viroids, with successful inoculation observed in all varieties. However, infection rates varied, with HSVd showing the highest rates of infection, followed by CBCVd and HLVd. This research enhances the understanding of viroid dynamics in hop plants, which is crucial for developing effective disease management strategies. Despite the insights gained, no resistance or tolerance to the viroids was identified in any of the tested hop varieties.