Viroids
A viroid closely related to coconut cadang-cadang viroid (CCCV) has been found infecting both coconut and oil palm in the Solomon Islands (CCCV itself having been reported only in the Philippines and the related tinangaja viroid only in Guam). The viroid may thus occur more widely and affect more species of Palmae than previously thought (D. Harold & J.W. Randles, Waite Agricultural Research Institute, Glen Osmond, South Australia 506, AU; abstract P. I-2-106).
Three new viroids have been isolated from grapevine in Australia, provisionally known as grapevine Australian viroid, grapevine yellow speckle viroid, and viroid 16. The two latter are related to apple scar skin viroid (EPPO Reporting Service
503/01) with which it is proposed to form a new viroid group. Only GYSV is associated with a disease (M.A. Rezaian & A.M. Koltunov, CSIRO, Adelaide, AU).
Latent or cryptic viroids occur in numerous crop plants and ornamentals, e.g. hop latent viroid found in practically all of 80 hops cvs from all over the world; variants of hop stunt viroid and citrus exocortis viroid found in rootstocks and scions of. grapevine, raspberry, plantain, croton, hibiscus. These latent viroids are transmissible and could cause disease in other species (H.L. Sanger et al., Max Planck Institut, Martinsried, DE)
Sources
Abstracts of the 5th International Congress of Plant Pathology, Kyoto (JP), 1988-08-20/27