We report the effect of UVoB irradiation (9.6 kJ m-2 day^-) on interspecific competition between two species of macroalgae, Ulva pertusa (U) and Grateloupiafilicina (G), in co-culture. Growth of U. pertusa and G...We report the effect of UVoB irradiation (9.6 kJ m-2 day^-) on interspecific competition between two species of macroalgae, Ulva pertusa (U) and Grateloupiafilicina (G), in co-culture. Growth of U. pertusa and G. filicina was inhibited by UV-B irradiation in mono-culture and specific growth rate (μ) declined as a result. Interspecific competition between U. pertusa and G filicina was closely related to the initial weights when co-cultured. When initial ratios of U. pertusa (U) to G filicina (G) were U:G=I.2:I and 1:1, U. pertusa was the dominant algae. When the initial U:G ratio was 1:1.2, G. filicina was competitively dominant in the earlier stage, but U. pertusa grew faster, superseding G. filicina in the later stage. At initial ration U:G = 1:1.4, G. filicina was predominant. Under UV-B irradiation, the competitive ability of G filicina was weakened and the interspecific competitive balance favored U. pertusa, which suggests that G. filicina was more sensitive to UV-B irradiation. We also probed the potential allelopathic effects between the two species, which led to mutual growth inhibition.展开更多
UV-B exposure (312 nm and 2.5 W.m^-2) caused 50 percent killing m Chlorella at lO mln and complete Killing at oo ram. Nitrate and phosphate uptakes were faster under UV-B irradiation than in fluorescent light. Short...UV-B exposure (312 nm and 2.5 W.m^-2) caused 50 percent killing m Chlorella at lO mln and complete Killing at oo ram. Nitrate and phosphate uptakes were faster under UV-B irradiation than in fluorescent light. Short exposure of UV-B stimulated nitrate and phosphate uptakes but inhibited ammonium uptake. Ammonium uptake was inhibited upto 30 min and thereafter increased and become constant after 60 min UV-B exposure. UV-B stimulated the nitrate uptake in deficient cells. Interestingly, there was rapid stimulation of nitrate uptake in deficient medium after 30 min UV-B treatment. Darkness inhibited the uptake mechanism but the fluorescent light enhanced the rate of nitrate uptake stimulation in deficient cells of Chlorella vulgaris.展开更多
基金Supported by the National Natural Science Foundation of China(No.30270258)the Natural Science Foundation of Shandong Province(No.2007ZRB01903)
文摘We report the effect of UVoB irradiation (9.6 kJ m-2 day^-) on interspecific competition between two species of macroalgae, Ulva pertusa (U) and Grateloupiafilicina (G), in co-culture. Growth of U. pertusa and G. filicina was inhibited by UV-B irradiation in mono-culture and specific growth rate (μ) declined as a result. Interspecific competition between U. pertusa and G filicina was closely related to the initial weights when co-cultured. When initial ratios of U. pertusa (U) to G filicina (G) were U:G=I.2:I and 1:1, U. pertusa was the dominant algae. When the initial U:G ratio was 1:1.2, G. filicina was competitively dominant in the earlier stage, but U. pertusa grew faster, superseding G. filicina in the later stage. At initial ration U:G = 1:1.4, G. filicina was predominant. Under UV-B irradiation, the competitive ability of G filicina was weakened and the interspecific competitive balance favored U. pertusa, which suggests that G. filicina was more sensitive to UV-B irradiation. We also probed the potential allelopathic effects between the two species, which led to mutual growth inhibition.
文摘UV-B exposure (312 nm and 2.5 W.m^-2) caused 50 percent killing m Chlorella at lO mln and complete Killing at oo ram. Nitrate and phosphate uptakes were faster under UV-B irradiation than in fluorescent light. Short exposure of UV-B stimulated nitrate and phosphate uptakes but inhibited ammonium uptake. Ammonium uptake was inhibited upto 30 min and thereafter increased and become constant after 60 min UV-B exposure. UV-B stimulated the nitrate uptake in deficient cells. Interestingly, there was rapid stimulation of nitrate uptake in deficient medium after 30 min UV-B treatment. Darkness inhibited the uptake mechanism but the fluorescent light enhanced the rate of nitrate uptake stimulation in deficient cells of Chlorella vulgaris.