Influence of thidiazuron on morphogenesis of leaf explants of Betula pubescens Ehrh. in culture in vitro

In the work, the dependence of the morphogenic and regenerative activity of leaf explants of Betula pubescens on their way of orientation on the nutrient medium and on the presence of thidiazuron in the medium is studied. Methods : cell culture in vitro; statistical analysis. The results obtained on the Betula pubescens (clone 3f1) indicate a high regenerative activity of the studied genotype. High growth-producing ability of thidiazuron in a concentration of 0,1-0,5 mg/l was noticed. It is shown that the orientation of the leaf blade on the medium can have a significant effect on the number of adventitious buds and shoots on the leaf and the frequency of regeneration, depending on the concentration of thidiazuron. Root formation was noticed in the 100% of explants cultured on a medium without hormones, when the leaf was adaxially placed on the medium. The percentage of rhizogenesis on leaf explants cultivated on media containing thidiazuron ranged from 17 to 57. There were from 1 to 7 roots of different length on the leaves. Differentiation of adventitious buds and shoots from callus tissue formed over the entire surface of the explant, and the development of adventitious kidneys induced in the first passage occurred in 76,7-100 % of explants in almost all experimental variants. A tendency has been revealed: most of the adventitious buds and shoots are formed on the side of the leaf blade that contacts the medium. The number of adventitious buds and shoots on the explants ranged from 1 to 50, depending on the concentration of thidiazuron in the first passage.