|
Abstract : |
Acid rain is one of the great importance stresses that are associated with atmospheric pollutions. This research tries to detect some microscopic effects of acid rain on pollen formation, development and structure. Bean plants were growed in plots in different groups and were treated by different acid solutions of HNO3, H2SO4 and both HNO3, H2SO4. The pH of each group regulated from 2-4.5. Experimental plants were sprayed with different acid solutions and control plants sprayed by distilled water. Treatments were taken for 4 weeks, one in each day. Young buds and flowers were removed and fixed by using FAA and stored in 70% ethanol. The specimens embedded in paraffin and sectioned at 8 μm with microtome. Staining was carried out with Hematoxylin and developmental stages were compared in treated plants and controls. Studies of microscopic preparation showed that acid rain could affect developmental process of pollen grains in plants that treated by acid solutions. In treated plants, numbers of pollen grains and also amount of fertile pollen grains were decreased in each anther significantly. Exine was not formed in some case of plants that treated by different acid solutions. Degradation of tapetum cells was take later in treated plants than control ones. This is cause to non-well feeding of developmental pollen grains that trend to some abnormalities during pollen development. Vesiculation of cytoplasm and accumulation of black particles are the results of acid treatments that were more evidence in treated plants. Treatment by HNO3, pH 2, is more effective than others regarding induction of abnormalities during pollen development and decreasing of pollen fertility., Acid rain is one of the great importance stresses that are associated with atmospheric pollutions. This research tries to detect some microscopic effects of acid rain on pollen formation, development and structure. Bean plants were growed in plots in different groups and were treated by different acid solutions of HNO3, H2SO4 and both HNO3, H2SO4. The pH of each group regulated from 2-4.5. Experimental plants were sprayed with different acid solutions and control plants sprayed by distilled water. Treatments were taken for 4 weeks, one in each day. Young buds and flowers were removed and fixed by using FAA and stored in 70% ethanol. The specimens embedded in paraffin and sectioned at 8 أƒإ½أ‚آ¼m with microtome. Staining was carried out with Hematoxylin and developmental stages were compared in treated plants and controls. Studies of microscopic preparation showed that acid rain could affect developmental process of pollen grains in plants that treated by acid solutions. In treated plants, numbers of pollen grains and also amount of fertile pollen grains were decreased in each anther significantly. Exine was not formed in some case of plants that treated by different acid solutions. Degradation of tapetum cells was take later in treated plants than control ones. This is cause to non-well feeding of developmental pollen grains that trend to some abnormalities during pollen development. Vesiculation of cytoplasm and accumulation of black particles are the results of acid treatments that were more evidence in treated plants. Treatment by HNO3, pH 2, is more effective than others regarding induction of abnormalities during pollen development and decreasing of pollen fertility., |
