[Localization of associative cyanobacteria on the roots of epiphytic orchids].

This work is the first study of the localization of phototrophic microorganisms in the rhizoplane and velamen of epiphytic orchids, namely on the aerial and substrate roots of Acampe papillosa and Dendrobium moschatum and on the aerial roots of the Phalaenopsis amabilis and Dendrobium phalaenopsis. The composition of the bacterial community on the plant roots depended on the conditions of plant growth. Under conditions simulating climate of moist tropical forests, the aerial roots proved to be populated with phototrophic microorganisms among which cyanobacteria predominated. Interlaced fungal hyphae and filamentous cyanobacteria formed a sheath on the surface of aerial roots. The nitrogen-fixing capacity of the sheath of aerial roots was studied by the example of P. amabilis.