Sequence analysis of three citrus viroids infecting a single Tunisian citrus tree (Citrus, reticulata, Clementine)

Abstract

We report the nucleotide sequences of three citrus viroids belonging to three different genera: Citrus exocortis viroid (CEVd), Hop stunt viroid (HSVd) and Citrus viroid-III (CVd-III) isolated from a single natural infected Citrus reticulata var. Clementine tree growing in a tree nursery in Manouba (near Tunis Capital). We describe the sequence variability of these viroids from their natural host without using an alternative passage by an indicator host or an artificial inoculation. This work confirms that naturally occurring viroid infections contain a mixture of sequence variants. These are the first sequences of citrus viroids from Africa

Single-Strand Conformation Polymorphism for Molecular Variability Studies of Six Viroid Species

“…Changes, including transitions, transversions, additions, and deletions and covering most variable sites in the viroid molecule were observed. 26) We also tested the ability of SSCP analysis to distinguish different clones of HSVd. The results showed that the present analysis was highly sensitive in distinguishing differences among clones.…”

First report of Hop stunt viroid infecting citrus orchards in Jamaica

“…Within 18 months, gumming at the bud union, an indication of infection with HSVd, was observed on Parson’s Special mandarin inoculated with samples from the Clarendon region. Total RNA extracted from the latter samples was subsequently used in reverse transcriptase‐polymerase chain reaction (RT‐PCR) with primers specific to HSVd (Elleuch et al ., 2006). Single fragments (∼ 283 bp) were amplified, cloned, and sequenced.…”