Viroid detection and identification by bioassay

Nie X and Singh RP. 2017. Viroid detection and identification by bioassay. Chapter 33. In “Viroids and Satellites” Hadidi A, Randles JW, Flores R, and Palukaitis P, ed. Academic Press/Elsevier. Page: 347-356.


Viroids are highly structured small circular RNAs that do not encode proteins but are able to replicate and cause diseases in plants. Characteristic symptoms caused by a viroid in a specific indicator host are the foundation of biological assay (bioassay) for detection and identification of the viroid. For bioassay of Solanaceae-infecting pospiviroids, a panel of indicator hosts are needed as similar types of symptoms may be induced by different viroids. For bioassay of citrus viroids, both citrus and herbaceous species are used. Many factors including environmental conditions, viroid strains, host species and genotype, and whether or not another viroid/virus is present, affect the bioassay. Combining bioassays with molecular assays for viroid detection and identification are also discussed.

Date modified: