Impact of Environmental and Stress Factors on the Photosynthetic Capabilities of Plants

摘要

Photosynthesis is the most fundamental and intricate physiological process in all green plants. For the fruitful occurrence of photosynthesis, each plant has certain environmental requirements. They are impacted by the environmental factors and stress during all phases of growth and development. Examples include light availability, water (soil moisture), senescence, carbon strategy and nutrient deficiencies etc. that cause alteration of the net photosynthesis rate of plants. In this study, to determine the effect of different environmental factors on photosynthesis, a number of experiments were conducted where the net photosynthesis, transpirations, water use efficiency and photoinhibition were measured. To study the effect of light intensity, soil moisture, senescence, on net photosynthesis, respectively Ocimum basilicum, Vaccinium vitis-idaea, Cotinus coggygria, were used. To compare carbon strategy, Pisum sativum and Zea mays were grown under similar condition. How variable nutrient conditions can affect the photosynthesis was studied using a light adapted plant Epilobium augustifolium and shaded tolerant plant Glechoma hederacea. Observations resulted that light intensity at mid-range increases the rate of photosynthesis but exceeding a certain amount caused lowering the efficiency. Net photosynthesis was the maximum under moist condition for Vaccinium vitis- idaea. On the other hand, the senescent leaf had highly similar transpiration rates as the healthy green leaf. Net photosynthesis rate of C4 plants were higher than C3 plants. Overall, the impact of environmental factors on the photosynthesis rate of different plant species was quite apparent.