稻田除草剂对固氮蓝藻的毒性研究

Study on Herbicides in Rice Fields to Toxicity of Fixing Blue -green Algaes

通过4种稻田除草剂对固氮鱼腥藻(AnabaenaazoticaLey)、球胞鱼腥藻(AnabaenasphaericaBorn)、多变鱼腥藻(AnabaenavariabilioKutzing)的毒性进行了研究。结果表明,二甲四氯对3种藻的生长有促进作用,而丁草胺和乙草胺在低浓度(8mg·L-1以下)表现为促进,当浓度为16mg·L-1时,则显著抑制其生长,且高浓度时对3种藻产生较强毒性,处理96h时的EC50值分别为12.87、25.36、20.21mg·L-1及50.52、18.37、45.43mg·L-1。3种藻对扑草净极为敏感,在低浓度时其生长受到严重抑制,继而迅速死亡。因此选择对固氮蓝藻安全的稻田除草剂,对维护稻田生态、促进农业可持续发展具有重要意义。

The toxicity test of herbicides in rice field on Anabaena azotica Ley,Anabaena sphaerica Born,Anabaena variabilio Kutzing,were carried out,The resul t showed that MCPA stimulated the gro wth of fixing Blue -green algaes,but butachlor and acetochlor could stimulate the grow th of fixing Blue -green algaes when t heir concentration were under 8mg ·L -1 ,and they would control obviously the growth r ate of fixing Blue -green algaes when their concentration were 16mg ·L -1 .Then,herbicides showed strong toxicity when they restrained under high concentration,a fter dealed with herbicides for 96h,the EC 50 of Anabaena variabilio Kutzing Anabaena azotica Ley and Anabaena sphaerica Born were 12.87,25.36,20.21mg ·L -1 in butachlor and50.52,18.37,45.43mg ·L -1 in acetochlor respectively.The nitrogen fixing Blue -green algaes show ed special sensitivity in prometryne treatments,and they wou ld be restrained hard even die soon under the low concentration.So choosing safe herbicides to Blue -green algaes may be importan t to protect ecosystem in rice fields and promote sustaining develop of agriculture.