Citrus Cachexia Viroid, a New Viroid of Citrus: Relationship to Viroids of the Exocortis Disease Complex

Hop stunt viroid (HSVd) sequence variants from Prunus species: evidence for recombination between HSVd isolates.

“…In some hosts, such as grapevine (Shikata, 1990 ;Polivka et al, 1996) and apricot (Astruc et al, 1996), the infection appears to be latent. In other cases, specific disorders such as hop stunt (Shikata, 1990), dapple fruit of plum and peach (Sano et al, 1989) and citrus cachexia (Diener et al, 1988 ;Semancik et al, 1988) have been associated with HSVd infection. Sequence variation between isolates affects all structural domains (Hsu et al, 1994), but little is known of the effect of specific mutations on the pathogenicity or host range of HSVd.…”

Nucleotide sequence and structural features of the Group III citrus viroids

“…Nevertheless, distinct properties including a characteristic symptom expression in citron (Citrus medica L.) of 'leaf-drooping' resulting from petiole bending (Duran-Vila et al, 1988 a), a relatively narrow size range of 280 to 292 nucleotides as estimated by sequential polyacrylamide gel electrophoresis (sPAGE), and sequence homology detected by hybridization with specific cDNA probes have been used to demonstrate the unique aspects of the Group III citrus viroids (Duran-Vila et al, 1988b;Semancik & Duran-Vila, 1991).…”

A stable 463 nucleotide variant of citrus exocortis viroid produced by terminal repeats

“…Secondary transmissions involved embedding a tissue piece from primary inoculum sources into the stems of healthy plants. Tip tissues from infected plants consisting of apex, young leaves and stems displaying severe symptoms of dwarfing, leaf epinasty and rugosity were homogenized and nucleic acids extracted as previously reported (Semancik et al, 1988).…”