Türkiye Tarımsal Araştırmalar Dergisi (Mar 2015)
Viroids and Viroid Disease Agents Detected in Turkey
Abstract
Viroids are circular, single-stranded RNAs that infect plants. Viroids belong to two families, Pospiviroidae and Avsunviroidae, whose members replicate in the nucleus and chloroplast of plant cells, respectively. The host range of viroids includes vegetable crops, ornamentals, and woody perennials, depending upon the viroid species. Viroids are easily transmitted mechanically through contaminated pruning tools. They can also be spread vegetatively by grafting, tuber propagation, infected seed, pollen, and insects. There are over 30 known viroid species that are taxonomically divided into two families. Viroids are also responsible for several cultivated plant diseases in Turkey. Viroids and viroid disease agents causing plant disease (Potato spindle tuber viroid, Chrysanthemum stunt viroid, Citrus exocortis viroid, Hop stunt viroid, Citrus cachexia viroid, Citrus viroid III–IV, Grapevine yellow speckle viroid 1–2, Avocado sunblotch viroid, Peach latent mosaic viroid) in Turkey were discussed in this review.
