| The purpose was to evaluate the environment toxicity of herbicide. We studied the acute toxicity effect, physiological toxicity effect and genetic toxicity effect of four kinds of herbicide on Misgurnus anguillicaudatus and Paramisgurnus dabryanus(Sauvage) through a cuople of toxicological methods. Including five preliminary study: acute text, genetic toxicity text(micronucleus text, single-cell gel electrophoresis), embryos and larvae toxicity text. The four kinds of herbicide are pretilachlor, butachlor, penoxsulam, fluoroglycofen. which also we hope we can provide scientific basis for monitoring the contaminating of the herbicide to environment and using herbicide properly.Through acute toxicity test, the SCs and LC50 s of 24 h, 48 h and 96 h are acquired. The LC50 s of 24 h, 48 h and 96 h of pretilachlor on Misgurnus anguillicaudatus are 6.676mg/L, 5.9455mg/L,5.1225mg/L. and the SC of pretilachlor on Misgurnus anguillicaudatus is 1.3785mg/L. The LC50 s of 24 h, 48 h and 96 h of butachlor on Misgurnus anguillicaudatus are7.622mg/L,5.74mg/L,3.624mg/L, and the SC of butachlor on Misgurnus anguillicaudatus is 0.8756mg/L. The LC50 s of 24 h, 48 h and 96 h of penoxsulam on Misgurnus anguillicaudatus are 37.3233mg/L, 34.1073mg/L, 26.9936mg/L. and the SC of penoxsulam on Misgurnus anguillicaudatus is 8.2467mg/L. The LC50 s of 24 h, 48 h and 96 h of fluoroglycofen on Misgurnus anguillicaudatus are 4.4614mg/L, 3.3443mg/L, 2.6303mg/L. and the SC of fluoroglycofen on Misgurnus anguillicaudatus is 0.5638mg/L.The LC50 s of 24 h, 48 h and 96 h of pretilachlor on Paramisgurnus dabryanus are 6.676mg/L, 5.9455mg/L, 5.1225mg/L. and the SC of pretilachlor on Paramisgurnus dabryanus is 1.4146mg/L. The LC50 s of 24 h, 48 h and 96 h of butachlor on Paramisgurnus dabryanus are 7.32mg/L, 5.337mg/L, 2.785mg/L, and the SC of butachlor on Paramisgurnus dabryanus is 0.8511mg/L. The LC50 s of 24 h, 48 h and 96 h of penoxsulam on Paramisgurnus dabryanus are 37.8416mg/L, 35.5345mg/L, 28.9641mg/L, and the SC of penoxsulam on Paramisgurnus dabryanus is 9.4001mg/L. The LC50 s of 24 h, 48 h and 96 h of fluoroglycofen on Paramisgurnus dabryanus are 4.8778mg/L, 3.5607mg/L, 2.6684mg/L. and the SC of fluoroglycofen on Paramisgurnus dabryanus is 0.5692mg/L.We study the genetic toxicity of four kinds of rice herbicides on two species of loaches from the micronucleus test and single cell gel electrophoresis test. Micronucleus test results show that, these four kinds of herbicide all can advance the different levels of the rate of abnormal nucleus of the two kinds of loach. Fluoroglycofen’s nuclear abnormality rates were the highest among them. In fluoroglyc ofen’s micronucleus test of loach showed that the rates of nuclear anomalies of erythrocyte is up to 7.18 per 1000 on the ninth day of 1.3mg/L treatment group.The induced degree of fluoroglycofe nethyl Pretilachlor> Ding Caoan> five mefluidide grass amine.Single cell gel electrophoresis test results showed that four kinds of rice herbicides can promote the tail of DNA content and olive tail moment of two loaches’ blood cells and liver cell effective. In Pretilachlor’s 3.4mg/L trearment group,the Loach Liver Cell tail DNA% and olive tail moment were as high as 52.60%and 159.86. Therefore,these four kinds of herbicide not only can bring genetic damage on red blood cells of two species of loaches,but also can bring DNA damage on blood cell and liver cells of two species of two loaches.Regarding two kinds of loaches’ liver tissues enzyme: superoxide dismutase(SOD), remains to have different sensitive degree, but the gap is not obvious. catalase(CAT) activity and glutathione(GSH) and malondialdehyde(MDA) content as the index of physiological toxicity test. The results showed that four kinds of herbicide can cause obvious oxidative stress effect on two kinds of loaches and loaches’ liver’s anti oxidase enzymatic activity was inhibited. The body’s antioxidant capacity decreased and showed more obvious oxidative damage.Regarding embryo deformity and mortality rate as the index, with four different embryonic stages(blastoderm uplift stage, gastrula, neurula stage, the middle tail bud stage) for processing time of embryo toxicity test. The results showed that four kinds of herbicide all can induce different extent in the two kinds of loach embryos hatch rate, deformity rate increased with toxic effect on two kinds of loach embryo. In addition, 1.3mg/L fluoroglycofen from neurula stage processing of large scale loachembryos, which can make the deformity rate as high as 66.12%, 3.4mg/L Pretilachlor from gastrula intermediate processing of large scale loach embryos, which can make the hatching rate as low as 48.40%.There are some differences effect in different rice herbicide on two kinds of loach embryo in most sensitive period.In the embryo toxicity text, with embryos hatching, deformity rate index to the four different periods of embryonic development(blastoderm uplifting, mid gastrula, neurula stage, tail bud stage) to start the processing time. In the results, the four kinds of herbicide can induce different degrees of two kinds of loach embryos reduced hatching rate, abnormalities and higher rates of embryonic development has a certain teratogenic, lethal effect.In larvae toxicity, The LC50 s of 96 h of pretilachlor, butachlor, penoxsulam, fluoroglycofen on Misgurnus anguillicaudatus larvae are 0.40197mg/L, 0.39223mg/L, 0.7696mg/L, 0.20708mg/L. The LC50 s of 96 h of pretilachlor, butachlor, penoxsulam, fluoroglycofen on Paramisgurnus dabryanus larvae are 0.3265mg/L, 0.16487mg/L, 1.25017mg/L, 0.23787mg/L.In summary, four kinds of rice herbicides all showed acute toxicity, genetic toxicity and toxicity on two species of loaches.They all bring damage to blood cell, hepatocyte DNA, embryos and larvae. In addition, two species of loaches of toxicity of four kinds of rice herbicides. |
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