Comparative Botanical Studies

Water availability is thought to be the most critical limiting factor for photosynthesis and hence for agriculture productivity. There is an increasing demand of the fresh water day by day in Agriculture, Industries Domestic and Electricity generation. The last three uses of water have affected the water quality adversely not only in Egypt, but also in many countries. These is the waste water which comprising of of domestic, sewage and industrial discharges mixture. Moreover, fresh water problem is comparatively more serious in Egypt due to the unequal distribution of water resources in the world (Anonymous, 2002). The deleterious effects of its lack on productivity reduction are reviewed (Opik et al., 2005).There is need to bring perceivable shift towards wastewater treatment, disposal and reuse. Response of plants to wastewater stress is influenced by the degree of stress, plant genotypes and its growth stage as well as the environmental conditions. (Nawar, 2009). Stress is considered to be a polygenic trait, and its expression is affected by various genetic, developments, physiological interactions within the plant, and between genotypes and external environments.