Disease Note.

Cadang-Cadang-Like Viroid in Oil Palm in the Solomon Islands. D. Hanold, Department of Plant Pathology, Waite Agricultural Research Institute, University of Adelaide, Australia 5064. J. W. Randles, Department of Plant Pathology, Waite Agricultural Research Institute, University of Adelaide, Australia 5064. Plant Dis. 73:183. Accepted for publication 29 September 1988. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0183A.

Several oil palms (Elaeis guineensis Jacq.) with symptoms resembling those associated with coconut cadang-cadang viroid (CCCV) infection in the Philippines (2) were observed in a plantation near Honiara, Solomon Islands. The youngest three or four fronds were green, but the remainder had numerous nonnecrotic bright orange spots 2-3 mm long. Affected palms were stunted, and bunches of nuts were reduced in size and number. Nucleic acid extracts of leaves were analyzed for CCCV by fractionation on polyacrylamide gels, electrotransfer of nucleic acids to nylon membranes, and subsequent hybridization assay with a p-labeled complementary RNA probe representative of the full sequence of CCCV. Nucleotide sequences specific for CCCV in nucleic acids corresponding in size to monomeric and dimeric forms (about 297 and 594 nucleotides, respectively) of the viroid were detected. Size and sequence are distinguishing properties of CCCV (1), and we conclude that an agent identical to, or closely resembling, CCCV is present in these palms. This is the first report of the occurrence of a cadang-cadang-like viroid outside the Philippines-Guam region and its first record in a commercial oil palm plantatioq.

References: (1) J. Haseloff et al. Nature 299:316, 1982. (2) J. S. Imperial et al. Plant Pathol. 34:391, 1985.