The Use of Cloned Sequences for the Identification of Coconut Foliar Decay Disease-associated DNA

Publisher Website
Google Scholar
Abstract
Single-stranded circular DNA associated with foliar decay disease of coconut palm in Vanuatu (FDD-DNA) has been purified and three fragments have been cloned in plasmid pUC19. Clones labelled with 32P by nick translation were used as specific probes for FDD-DNA in dot blot and Southern transfer hybridization assays. These assays were more sensitive than the polyacrylamide gel electrophoresis assay developed previously for diagnosis of FDD. Hybridization tests showed that FDD-DNA had no detectable sequence similarity to the geminivirus infecting Digitaria sanguinalis which grows alongside FDD-infected coconut palms; that Hibiscus tiliaceus, which is the host plant of the vector of FDD, Myndus taffini, is not infected with FDD-DNA; and that the symptomless coconut variety, Vanuatu Tall, is susceptible to infection with FDD-DNA. Native FDD-DNA migrates as two distinct bands in polyacrylamide gels, and both hybridize to the probe. Previous estimates and data presented here show that FDD-DNA is approximately half the size of the D. sanguinalis geminivirus DNA (approx. 2350 nucleotides) and support the view that FDD is caused by a virus not typical of any plant virus taxonomic group.