Home – Home – Jornals – Contemporary Problems of Ecology 2023 number 5

Betula pendula Roth. is tolerant to tehchnogenic air pollutants. However, the viability of pollen decreases under stress conditions, as well as under air pollution. The researches were conducted in Middle Siberia on eight plots of motley birches near industrial city of Krasnoyarsk. In each plot on west side of 15-20 trees, male twigs were cut at pollination time. Pollen was extracted from the male generative organs for size and viability (potential, by starch test, and realized, by in vitro germination) determination. The results were analyzed by statistical methods. The researches have revealed reduction of pollen viability under technogenic pollution and reliable differences in pollen grain diameters under different growing conditions, whereas deformed pollen grain were not revealed. The variability of pollen grains in diameter in the biocenosis did not exceed 9.3-9.9 %. Maximum number of sprouted pollen grains observed under background conditions, and minimum at the eastern border of city in the main direction of the transfer of technogenic aerosols. The length of pollen tubes in trees growing under these conditions decreased by more than twice in comparison to the critical value (namely, pollen grain diameter of 18-20 µm). Regression analysis has shown correlations between pollen germination and accumulation of dust on foliage, as well as of lead and aluminum content in the foliage ( r = - 0.1-0.3, р ≥ 0.05)). In spite of tolerance of the species to air pollution, Betula pendula male generative structures are sensitive to the contamination. Pollen viability can be used as a bioindicator of environmental pollution at monitoring.