Betula pendula Pollen Viability in Suburban Biocenoses with Different Technogenic Loads

Betula pendula Roth. is tolerant to technogenic air pollutants. However, the viability of pollen decreases under stress conditions, as well as under air pollution. This research was conducted in Middle Siberia on eight plots of motley birches near the industrial city of Krasnoyarsk. In each plot on the west side, the male twigs of 15–20 trees were cut at pollination time. Pollen was extracted from the male generative organs for size and viability (potential (by starch test) and actual (by in vitro germination)) determination. The results were analyzed by statistical methods. A reduction in pollen viability under technogenic pollution and reliable differences in pollen grain (PG) diameters under different growing conditions is revealed, but deformed PG is not. The variability of PGs in diameter in the biocenosis does not exceed 9.3–9.9%. The maximum number of sprouted PGs is observed under background conditions and the minimum is at the eastern border of the 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 with the critical value (namely, PG diameter of 18–20 µm). Regression analysis has shown correlations between pollen germination and the accumulation of dust on foliage, as well as of lead and aluminum content in the foliage (r = − 0.1−0.3, р ≥ 0.05). Despite the tolerance of the species to air pollution, Betula pendula male generative structures are sensitive to contamination. Pollen viability can be used as a bioindicator of environmental pollution upon monitoring.