background and aims: viroids are smallest known plant pathogens and cause several economically significant diseases. until recently, viroid detection relied mainly on biological tests and indexing. today various diagnostic techniques such as nucleic acid hybridization, southern blot and reverse transcription coupled with polymerase chain reaction (rt-pcr) are being used for detection and diagno...

A large body of evidence has lead to the suggestive proposal of a potential interplay between viroid-induced pathogenesis and RNA silencing regulatory mechanisms. A variety of techniques have been used to examine this interaction. This chapter outlines the use of a green fluorescent protein (GFP) sensor, containing viroid-specific sequence targets to study this phenomenon. In addition, a sympto...

plant samples were collected from yazd, isfahan, fars and tehran provinces and examined for their possible infection by hop stunt viroid (hsvd). the experimental host range of the viroid was determined by injection of infected sap into greenhouse grown seedlings and subsequent assay of inoculated plants by rt-pcr. fig, mulberry and citrus isolates of the viroid were compared with respect to hos...

in this study, the possible infection of thomson navel, moro blood sweet orange, page mandarin and webber pomelo with citrus viroids was investigated. biological indexing was performed by grafting on etrog citron (c. medica) and maintained in temperature-controlled greenhouse. after inoculation, rna was extracted by sds– potassium acetate method. detection of citrus viroids was done reverse tra...