Effects Of Algaecide On Tribonea Bloom Of Chlorophyll A Content And Antioxidant Enzyme Activity

Four kinds of algaecide on the Tribonea bloom chlorophyll a content and antioxidant enzyme activities in experimental studies, common form of filamentous algae blooms were described and types of algae were identified, and "si zao sha" was used to control filamentous algal blooms in Field study, In order to find the basic theory and application of technology to control filamentous algal blooms in aquaculture pond.According to the standard method of algae growth inhibition, tribonema sp, which were taken from the bottom of pond, were exposed by different concentrations of sulfuric copper,isothiazolone ketone,prometryn,metribuzin, and sampled at the different time. Then the chlorophyll a (Chl a) levels were measured by spectrophotometer, and malondialdehyde (MDA) content, superoxide dismutase (SOD) and catalase (CAT) activitives were measured using corresponding kits,the results showed that:The toxicity enhanced while the concentration of sulfuric copper grown. At the concentration of 2.40mg / L, the Chl a content, SOD, and CAT activity reached to the minimum, but the MDA content achieved to the peak, At the concentration of 0.42mg/L, no significant differences (P> 0.05) between measurements and the control group were observed. As the exposure time increase, more obvious toxicities were observed. At 72h, SOD activity of all the concentrations reached to the max, despite exposuring to various concentrations,but the SOD activity depressed sooner with the time delaying. At 72h, the MDA content of concentration of 1.36mg/L and 2.40mg/L showed the max, and decreased later; At 96h, SOD activities of 2.40mg/L existed as the lowest, while the MDA content reached its peak.The toxicity enhanced while the concentration of isothiazolone ketone grown , at the concentration of 2.40mg / L, the contents of tribonema sp's chlorophyll a and malondialdehyde had significant differences to the controls at 96h, but the superoxide dismutase activity at a low level. At the concentration of 2.40mg / L, there were no significant differences between each measured value with the control group. Tribonema sp was more and more serious poisoning with the exposure time increased, at 72h, the MDA content reached to highest of each concntration, and then decreased, exposed to 96h, only the concentration of 2.40mg / L of CAT was significantly different from control group (P <0.05), and also at the highest activity.The toxicity enhanced while the concentration of Prometryn and time grown, at the concentration of 0.49mg/L,the content of chl a and MDA, the activities of SOD and CAT, had significant difference to the control group, and the activity of SOD,CAT reached to the maximum; the content of MDA reached to the maximum at 72h.The toxicity enhanced while the concentration of Metribuzin and time growna, at 96h, the content of chl a and MDA, the activities of SOD and CAT, had no significant difference(p>0.05) to the control group at the concentration of 0.16mg/L, the content of chl a and MDA, the activities of SOD and CAT, had significant difference(P<0.05)to the control group at the concentration of 0.49mg/L, however, the antioxidant enzymes was still in the induction state.The results of Copper sulfate, isothiazolone ketone, prometryn, and metribuzin on the tribonema sp's effect concentration 50% showed that the toxic of four algaecide became more and more stronger with the time going , and copper sulfate was the most toxic algaecide.The effect of copper sulfate, isothiazolone ketone and prometryn to tribonema sp's activity of SOD and CAT, content of MDA showed the same trend, that was induced by low concentration, and inhibited by high concentration, but the metribuzin had been showing induced state, indicated that the concentration of metribuzin under the test did not cause excessive damage to tribonema sp.The form and type of Filamentous algal blooms was identified through micro filming technology in culture water of Dangtu ,Wuhu Anhui , Xinghua Jiangsu , Xiapu Fujian and scenic water of Expo Park,which indicated that the form filamentous algae of culture water and scenic water were types of Tribonema and Spirogyra. Tribonema bloom mainly outbreaks in spring and autumn, while Spirogyra bloom in summerThe field experiment results of spraying and splashing"si zao sha"in culture water with large spread of filamentous algal blooms showed that"si zao sha"can control the filamentous alga well, and you can find the appropriate mode of administration by filamentous algae outbreaks in different water bodies .