Abstract Background and Aims: Apple scar skin disease (ASSD) is one of the destructive diseases of pome fruits which is caused by ASSVd. Case presentation: We report molecular detection of ASSVd in symptomatic apples cv. Red Delicious with simultaneous presence of a new variant of HSVd from Khorasan Razavi province. Conclusion: This is the first report on the association of HSVd with...

The sequence of the 356 nucleotide residues of chrysanthemum stunt viroid (CSV) has been determined. Overlapping linear viroid fragments were obtained by partial ribonuclease digestion, radiolabelled in vitro at their 5'-ends, and sequenced using partial enzymic cleavage methods. Of the CSV sequence, 69% is contained in the published sequence of potato spindle tuber viroid (PSTV). Differences i...

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 diag...

Citrus Bent Leaf Viroid (CBLVd) and Dwarfing (CDVd), from genus Apscaviroid, are two of the widely distributed citrus viroids among eight reported to date. They have been found induce reduction in canopy volume fruit production trees on trifoliate orange hybrids rootstocks. Moreover, infected only with CBLVd or combinations Exocortis (CEVd), Hop Stunt (HSVd) CDVd associated a poor development r...

Background and Aims: Plant certification programs need reliable, fast, cheap and sensitive methods for detection of systemic pathogens with special interest in virus and viroid detection. Reverse transcriptase-polymerase chain reaction (RT-PCR) has been documented as an alternative assay for certification of plant propagating materials. The main object of the present study was the optimization ...