| In the paper,domestication of Daphniopsis tibetana.It focuses on researching the influence of Li~+on Daphniopsis tibetana magna toxicity.In the salinity of 15±1,water temperature of15±1 ?,we observed the population dynamics and reproduction of Daphniopsis tibetana,researched the effect of Li~+on the survival and reproduction of Daphniopsis tibetana,and made a life table.The experiment also select Daphnia magna(fresh water indicator species)and Moina Mongolia(water indicator species)as a comparative experiment.Through the experimental research on the influence of Li~+on Daphniopsis tibetana and Moina Mongolia and the influence of the difference of the Daphniopsis tibetana.The toxicity experiments on antioxidant enzymes of three kinds of Daphnia were analyzed.In order to further explore the relationship between the Li~+of Daphniopsis tibetanad and Daphnia magna?Moina Mongolia.The results show that:1.In the acute toxicity of Li~+to Daphniopsis tibetana,the half lethal concentrations of 24 h and 48 h were 395.454 mg/L and 285.642 mg/L,95% confidence intervals were375.383~420.646 and 272.374~299.064,the safe concentration was 44.709 mg/L.To Daphnia magna,the half lethal concentrations of 24 h and 48 h were 17.26 mg/L and 9.706 mg/L,95%confidence intervals were 15.377~19.812 and 8.466~10.982,the safe concentration was 0.9204mg/L.To Moina Mongolia,the half lethal concentrations of 24 h and 48 h were 40.664mg/L and32.245 mg/L,95% confidence intervals were 35.959~45.501 and 27.286~37.002,the safe concentration was 6.0824 mg/L.The tolerance range of Daphniopsis tibetana to Li~+is very wide(5~460mg/L),its far higher than that of Daphnia magna and Moina Mongolia.2.Compared with the control group,the concentration of Daphniopsis tibetana groups intrinsic growth rate(rm)and the finite rate of increase(?)increased with the increase of concentration;Daphnia magna showed with the concentration increased first and then decreased;Moina Mongolia showed increased with concentration increased.Li~+intends to Daphniopsis tibetana net reproductive rate(R0)and the mean generation time(T)increased first and then decreased;Li~+on Daphnia magna net reproductive rate decreased,the mean generation time increased firstly and then decreased;Mongolia Moina net reproductive rate and the mean generation time decreased.Three kinds of Daphnia adapted to Li~+mechanism for Daphniopsis tibetana > Moina Mongolia > Daphnia magna.3.This experiment studied the effects of different concentrations of Li~+to Daphniopsis tibetana and Daphnia magna,Moina Mongolia enzyme activity,including SOD,AKP,CAT,T-AOC,H2O2,MDA,GST.To Daphniopsis tibetana,with the increase of Li~+concentration,the activity of SOD decreased,the activity of SOD in the blank group was lower,and the concentration of 200mg/L group was slightly higher.It indicates that the effect of self defense mechanism of Daphniopsis tibetana quasi macrocopa.APK of Moina Mongolia and Daphniopsis tibetana activity did not change significantly at 24 h,48 h increased first and then decreased.24 h Daphniopsis tibetana CAT was first increased and then decreased,and H2O2 increased with the increasing concentration.48 h increased with the increase of the concentration of CAT,H2O2 increased first and then decreased.As a kind of metabolic waste,H2O2 has a certain harm to the organism,but the CAT is just accelerated metabolism in 48 h,which can be more rapid elimination of waste,the two in the biological function of mutual coordination.When 24 h,the concentration of T-AOC was increased in each concentration group.When 48 h,the concentration of T-AOC was significantly lower than that of the blankgroup,which indicated that the antioxidant mechanism had been damaged.Three Daphnia GST in 24 h and 48 h were at first increased and then decreased,MDA and GST are just the opposite trend. |
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