water deficit, ultraviolet radiation and carbon dioxide enrichment are the most important environmental factors in global climate change. this research was conducted in tarbiat modares university, research greenhouse and the objective of that was to study the effects of three levels of carbon dioxide (500, 900 and 1300 ppm), uv-radiation (uv-a, b and c with intensity of 18, 25 and 40 µw.cm2 res...