UV-B effect on constituents of Azolla caroliniana.
نویسندگان
چکیده
Changes in growth and ultrastructure of Azolla caroliniana in response to elevated UV-B radiation were investigated. Exposure of plants to UV-B radiation for 1, 8, 16, 24 and 48 h exhibited a significant decrease in biomass and relative growth rate. This decrease resulted in an increase in doubling time over the control. Also, Chl a and b contents were significantly decreased especially after 16 h. The reduction was accompanied by a decrease in 5-aminolaevulinic acid content (precursor of chlorophyll). On the other hand, contents of carotenoid and UV-absorbing phenolic compounds (flavonoids and anthocyanins) were increased.
منابع مشابه
Removal of contaminants in a paper mill effluent by Azolla caroliniana
This study was focused on removal of various parameters in paper mill effluent using a method called bioremediation by Azolla caroliniana. The experimental investigations have been carried out using Azolla caroliniana for conducting the sorption study with various dilution ratios (2, 4, 6, 8, and 10), pH (3, 4, 5, 6, 7, 8 and 9) and biomass (200, 400, 600, 800 and 1000 g). Th...
متن کاملEffect of Ultraviolet-B (280 to 320 nm) Radiation on Blue-Green Algae (Cyanobacteria), Possible Biological Indicators of Stratospheric Ozone Depletion.
The effect of ultraviolet-B (280 to 320 nm) irradiation on physiological activities of Anabaena flos-aquae and the water fern Azolla caroliniana has been studied under conditions where lethal effects of irradiation are absent. Nitrogenase activity, measured as acetylene reduction, specifically declined during irradiation with low levels of ultraviolet-B, whereas other physiological activities w...
متن کاملAltered nitrogenous pools induced by the azolla-anabaena azolla symbiosis.
The free amino acid and ammonia pools of Azolla caroliniana were analyzed by quantitative column chromatography on columns capable of separating all of the nitrogenous constituents normally found in physiological fluids. Comparisons were made of plants containing symbiotic algae and grown on nitrogen-free media, plants grown on media containing nitrate, and algae-free plants also grown on nitra...
متن کاملPerformance of Azolla caroliniana Willd. and Salvinia auriculata Aubl. on fish farming effluent.
The increasing release of untreated fish farming effluents into water courses that flow to the Pantanal wetlands in Mato Grosso (Brazil) may drive this ecosystem to eutrophication. Therefore, the growth of Azolla caroliniana Willd. and Salvinia auriculata Aubl. in fish farming effluent and their effect on its quality were evaluated for 48 days in a greenhouse. The results were compared to those...
متن کاملOccurrence and ultrastructural characterization of bacteria in association with and isolated from Azolla caroliniana.
The occurrence and ultrastructure of bacteria in leaf cavities of symbiotic Azolla caroliniana were examined by transmission electron microscopy. Bacteria were observed in all leaf cavities of Azolla cultures. Five ultrastructurally distinct types of bacteria were observed in each individual leaf cavity. Features used to characterize the bacteria included morphology, cell wall structure, and cy...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Zeitschrift fur Naturforschung. C, Journal of biosciences
دوره 62 3-4 شماره
صفحات -
تاریخ انتشار 2007