[Axenic cultures of Aponogeton distachyus L].

For investigations of the auto-, mixo-, and heterotrophy of higher plants, the plants must be fed organic compounds. This is more easily accomplished with submerged water plants than with terrestrial plants. Until now, only relatively small and frequently reduced plants were used for this purpose. The present investigations with Aponogeton distachyus L. show that larger submersed plants can also be grown in axenic culture. The entire development from seed germination to flower formation of plants with almost one meter long leave and inflorescence stalks was accomplished in culture vessels of 5-8 litre capacity. This is possible only because the submerged plants do not develop supportive tissue and therefore grow around the walls of the vessel. In one case, the development of inflorescence occurred even in a one-litre flask. Vegetative development and flower formation were promoted by a variety of sugars but not by acetate. Development in the dark was not possible for an unlimited time. The tubers that were obtained in culture were successfully divided and used for the formation of clones.