NOVÉ POZNATKY O REPRODUKCI TOPOLU ŠEDÉHO V IN VITRO PODMÍNKÁCH.

The main goal of the presented study is to explore an effective micropropagation method for grey poplar (Populus ×canescens Aiton (Sm.)), which belongs to woody plant species characterized by rapid growth and early reproductive maturity. The influence of three culture media - Murashige and Skoog medium (MS), woody plant medium (WPM), and medium according to Lambardi et al. (2000) (LAM) differing in nutrition and phytohormone compositions have been followed in relation to shoot-tip segments growth. The best results have been achieved on MS medium enriched in glutamine (10 mg.l-1), glycine (2 mg.l-1), BAP (0.2 mg.l-1) and IBA (0.1 mg.l-1), even though the concentrations of photosynthetic pigments were comparable with apical segments cultivated on WPM medium. In addition, faster shoot regeneration and subsequent proliferation were observed in excised apical segments on selected MS medium in comparison to excised nodal segments, in which lateral buds formations was unequal and delayed due to excessive adventitious shoots formation at the base of segments. These results clearly indicate the importance of medium composition and a part of segments used for efficient in vitro micropropagation technique of grey poplar. [ABSTRACT FROM AUTHOR]