Abstract
The purpose of this work is to comparatively assess pollen viability of five plant species growing in different areas of the city of Aktobe, Kazakhstan (N 50Њ18¢, W 57Њ10¢). Pollen viability was assessed through iodine staining on the samples of pollen grains harvested between April and June 2017 from 100 plants of 5 species growing in the industrial zones, parks, and along highways: Ulmus laevis Pall., Ulmus pinnato-ramosa Dieck., Acer negundo L., Syringa vulgaris L., Populus tremula L. The minimum percentage of fertile pollen grains that was found in Ulmus laevis species has been detected in samples from the industrial zones, up to 68%.For Ulmus pinnato-ramosa, the minimum proportion of fertile pollen grains was 30%.For Acer negundo and Syringa vulgaris, similar trends were obtained.All plant species except Ulmus laevis (0.42) and Populus tremula (0.37) showed no relationship between the size of pollen grains and the intensity of their color change.Among all plant species under study, two (Ulmus laevis and Populus tremula) had the potential to act as model plant species and bioindicators of urban pollution.All five plant species demonstrated the highest proportion of defective pollen grains in the industrial zones, up 98%.