Study of the effect of UV-B radiation on morphological, anatomical and biochemical traits of Aptenia cordifolia

Increasing of the atmospheric pollution and reducing of the thickness of the ozone layer has increased dramatically the absorbance of ultraviolet radiation. Among the UV radiations, UV-B has the greatest impact on physiological processes and growth parameters of some plant species. In this study, the effect of UV-B (40 w.m-2) was investigated on Aptenia cordifolia plants in germination and vegetative stages. The experiments were conducted in a completely randomized design with three replications in four different periods of UV-B radiation including 0, 45, 90 and 120 minutes per day during 15days. The results showed that with increasing of the level of irradiation, the percentage and rate of germination and growth parameters such as seedlings height, the fresh and dry weight of root and shoot were decreased significantly. Concerning anatomical characteristics, we observed an increase in stem diameter number of vascular bundles. In the transversal section of roots, we observed a decrease in the root diameter and number of vascular bundles. Concerning the biochemical characteristics, the content of photosynthetic pigments and phenolic substances were decreased with increasing of the level of stress compared to control conditions

کلیدواژه ها:

Aptenia cordifolia ، Anatomy ، Morphology ، UV-B