Induction of direct somatic embryogenesis in leaf explants of Ulmus glabra

Ulmus glabra is a economical important tree species found in forests. However it is endangered due to high susceptibility to Dutch Elm Disease. Therefore, an efficient micropropagation method is important for breeding and genetic improvement of elm. This is the first report on induction of direct somatic embryogenesis from in vitro leaf explants in elm. The first experiment conducted with MS medium supplemented with different concentrations of BA or Kin or TDZ under light condition. Second experiment, carried out with MS basal media supplemented with 200 mg l–1 casein hydrolysed and different levels of 2,4-D and Kinetin in darkness. In third experiment 1/2 MS media supplemented with 200 mg l–1 casein hydrolysed and low levels of 2,4-D in combination with Kin were used, and the effects of light and darkness were investigated. Globular somatic embryos were achieved directly just on small leaves of genotype 2 in experiment 3. Non-embryogenic calli were induced in other experiments. The frequency of embryogenesis in most of the treatments of experiment 3 was 100%. However high number of embryos per explants was achieved in presence of 0.2 mgl-1 2,4-D without Kin (60.48) and 0.4 mgl-1 2,4-D combined with 0.2 mgl-1 Kin (47.76). Additionally, the percentage of embryogenesis and the average number of embryos per explants were higher in dark compared to the light condition.