Plant pathogenicity and transmission tests with Acholeplasma spp. isolated from coconut palms in Jamaica

Abstract

SUMMARYIsolates of Acholeplasma spp. cultured from lethal yellowing‐diseased coconut palms were characterised by polyacrylamide gel electrophoresis (PAGE) of cell proteins and by serological tests. Analysis of PAGE profiles placed 23 of the isolates in either of two related subgroups, (1A) or (IB), which show similarities to A. axanthum; 11 isolates were placed in group (2) which show similarities to A. oculi; and a single isolate formed a unique category (3). Serological relationships determined by fluorescent antibody and growth inhibition tests were in broad agreement with the PAGE classification. There was no evidence of transmission to plant hosts following injection of representative isolates into the cicadellids, Chlorotettix spp., Dalbulus maidis, Euscelidius variegatus or the cixid, Myndus crudus. Some isolates consistenty multiplied in E. variegatus following injection but were not acquired or transmitted during feeding through membranes. Antiserum to A. axanthum did not react with diseased or healthy palm tissues in enzyme‐linked immunosorbent assay and the recovery of further acholeplasma isolates from palms affected by bud‐rot disease demonstrated that these organisms were not specifically associated with lethal yellowing. The results suggested that these acholeplasmas are epiphytes or saprophytes on coconut palms.