The Influence of Drought on Growth and Development of White Poplar Shoots In Vitro

The study tested the effect of drought on growth and development of the shoots of five white poplar (Populus alba L.) genotypes (L-12, L-80, LBM, LCM and Villafranca) cultured in vitro. The effect of four different concentrations of polyethylene glycol (PEG 6000) (1 g/l, 10 g/l, 20 g/l and 50 g/l) in the rooting medium and the rooting medium without PEG (used as Control) were studied. After 35 days of cultivation, following characters were measured: height of shoot, number of roots, length of the longest root, the percentage of survival and rooting. According to the analysis of variance, effects of the media, genotypes and interaction genotype × medium were statistically significant for the most of examined characters. The best differentiation of genotypes was achieved on medium in which the PEG concentration was 50 g/l, so this medium was then used in drought tolerance evaluation. The best drought tolerance was achieved by the Villafranca genotype, which had the highest values of the height of shoot, the number of roots and percentage of rooting. Presented results suggest that testing of drought tolerance in vitro is a useful method for evaluation of white poplar genotypes. However, the research should be widening on the other parameters and set comparative experiments related to the tests in the field conditions.