MANIFESTATION OF THE TRAIT OF AERIAL ROOT-FORMATION IN THE RELICT SPECIES DIOSCOREA-BALCANICA KOSANIN AND DIOSCOREA-CAUCASICA LIPSKY

The morphogenetic pathway of aerial tuber formation suppressed under n atural ecological conditions can be clarified in the relict plants Dio scorea balcanica Kosanin and D. caucasica Lipsky using the method of c ulture in vitro. Formation of microtubers from lateral stem buds in th e leaf axil was induced in culture on stem cuttings with one or two in ternodes. On Murashige and Skoog nutrient medium containing 2% sucrose at daylength of 16 h, about 30% of the plants manifested the trait of microtuber formation. The presence of 6-BAP stimulated formation of m icrotubers in culture. Microtubers formed at the stem base and axillar y microtubers on nodes germinated to form roots initially and later a stem. Tubers separated from the starting plant developed in test tube culture. Induction of microtuber formation represents one more means o f vegetative propagation of these rare vanishing plants that need to b e conserved.