[Microbiota of the Orchid rhizoplane]

Six bacterial strains isolated from the underground roots of the terrestrial orchid Calanthe vestita var. rubrooculata were found to belong to the genera Arthrobacter, Bacillus, Mycobacterium, and Pseudomonas. Strains isolated from the aerial roots of the epiphytic orchid Dendrobium moschatum were classified into the genera Bacillus, Curtobacterium, Flavobacterium, Nocardia, Pseudomonas, Rhodococcus, and Xanthomonas. The rhizoplane of the terrestrial orchid was also populated by cyanobacteria of the genera Nostoc and Oscillatoria, whereas that of the epiphytic orchid was populated by one genus, Nostoc. In orchids occupying different econiches the spectra of the bacterial genera revealed differed. The microbial complex of the terrestrial orchid rhizoplane differed from that of the surrounding soil.