Leaf Primordia-Free Shoot Apical Meristem Culture: A New Method for Production of Viroid-Free Plants

Abstract

Viroids are the smallest and one of the most problematic pathogens known in horticulture. Despite not coding for proteins they replicate in nuclei or chloroplasts using host enzymes. From many pathological studies, it is obvious that viroids are completely different agents from viruses. For the past 40 years, elimination of viroids from infected plants has been the main theme in horticulture and several approaches have been established; however, these procedures remain complicated. Leaf primordia-free shoot apical meristem culture is a newly established method that can effectively eliminate viroids. Therefore, in this review, the method is summarized and the mechanism of viroid elimination is discussed.