Micromorphological and anatomical study of pollen for widely used ornamental plants in some polluted areas of Tehran Province

Many parks and green spaces in Tehran are located in polluted areas in order to reduce some air pollution; however, sometimes the plants themselves are damaged which cannot be easily recognized. The studied ornamental plants were collected, their pollen were separated from the anthers, and their purification was done by Erdtman's acetolysis method. They were stained with methylene blue and Lugol's solution and the pollens prepared for microscopic observations. Morphological changes of pollens with regional depressions (shrinking), changes in the size of the space between the exine and intine, tearing, asymmetry and deformation of pollen were observed. In the anatomical results some pollen grains were vacuolated and larger than normal, and some others were starchy and contained accumulations of contaminated particles. All these changes damage the pollen performance. Dahlia variabilis Dest. 97% and Tagetes patula L. 83% experienced the most anatomical damages and Rosa hibrida L.  46% and Datura innoxia Miller 24% underwent the most morphological damages.