Clonal degeneration is mainly due to:
Clonal degeneration is progressive decline in vigor, yield, and quality of a clone over successive vegetative generations despite genetic identity maintained by mitosis. Major cause is systemic accumulation of viruses, phytoplasmas, and viroids in phloem and meristems, transmitted mechanically through propagules because sexual filter absent that normally excludes many pathogens. Potato seed tubers accumulate Potato Virus Y and Leafroll Virus, sugarcane accumulates mosaic virus and ratoon stunting disease, banana accumulates Bunchy Top Virus, strawberries accumulate mottle viruses. Mixed infect
Ref: Loebenstein G & Katis NI. Plant Virus Diseases in clonal crops; Faccioli G. Potato degeneration review
