Home – Home – Jornals – Contemporary Problems of Ecology 2023 number 3

The resistance of Populus alba × P. bolleana No.7, P. alba × P. bolleana No.12 и P. davidiana × P. bolleana cv. Baichen 1 to osmotic stress in vitro has been investigated. Hybrid No. 7 was shown to tolerate up to 250 mM d-mannitol, whereas Baichen 1 variety only up to 50 mM d-mannitol in the nutrient medium after a 30-day culture period. Hybrid No. 12 remained viable at d-mannitol concentrations up to 150 mM. The use of d-mannitol significantly reduced the parameters of the leaf blade (length, width, leaf area) only in hybrid No. 7, for the rest of the samples the differences were insignificant (p < 0.05). The introduction of the osmotic component led to a decrease in the fresh and dry weight of all the studied samples by 1.7-2.2 times, while the water content of the tissues remained practically unchanged. The results of this study were confirmed by micromorphological parameters (stomatal apparatus and pubescence) in relation to drought tolerance. Poplar Baichen 1 was characterized by the weakest pubescence and the highest density of stomata (155.44 pieces/mm²), poplar No. 7 - the most dense pubescence and the smallest number of stomata per unit area (127.75 pieces/mm²). No direct relationship was found between the impact of osmotic stress and the number and size of stomata in the studied samples. We have shown that the studied poplar hybrids have different resistance to osmotic stress under in vitro conditions. More drought-tolerant hybrid No. 7 can be recommended for landscaping urban areas with increased anthropogenic pressure.