Grapevine leafroll-associated virus-3 (GLRaV-3) and Grapevine fleck virus (GFkV) are significant viral pathogens commonly found in the form of mixed infections in V. vinifera 'Shine Muscat' in Korea, which severely limits the production of virus-free planting materials.This study assessed the effects of ribavirin chemotherapy (20 and 40 mg L -1 ), thermotherapy at 37C, and treatments that combine these two actions on in vitro growth, shoot-tip regeneration stability, and virus elimination efficiency in mixed virus-infected 'Shine Muscat' plantlets.The thermotherapy and the combined treatments resulted in relatively stable shoot growth in vitro, while the ribavirin treatment alone tended to inhibit shoot elongation, although this treatment resulted in limited root damage.The survival rates of regenerated plantlets after shoot-tip culturing varied by treatment, ranging from 50.0% (R40+T) to 80.9% (R20).All treatments exhibited higher mixed-infection elimination rates than the untreated control (47.6%), defined as plantlets without thermotherapy or the ribavirin treatment.Among them, the combined thermotherapy-ribavirin treatments showed the highest efficiency levels, with elimination rates of 82.4% (R20+T) and 92.3% (R40+T).These findings suggest that combining ribavirin with thermotherapy can significantly enhance the elimination efficiency of mixed viral infections while maintaining acceptable levels of growth and regeneration stability.This study lays a practical foundation for optimizing treatment conditions for the nurserylevel production of virus-free 'Shine Muscat' grapevines.
Kim et al. (Tue,) studied this question.