【作者】 张磊；

【导师】 段舜山；

【作者基本信息】 暨南大学 ， 生态学， 2010， 硕士

【摘要】 为了进一步认识有机磷农药污染对海洋赤潮藻的毒物刺激效应规律,深入了解有机磷农药残留是否构成引起海洋赤潮发生的因素,实验设置了0、0.001、0.01、0.1、1和10 mg·L-16个质量浓度梯度,研究了草甘膦异丙胺盐和敌敌畏对典型赤潮藻球形棕囊藻(Phaeocystis globosa)和赤潮异弯藻(Heterosigma akashiwo)生长速率、色素含量、可溶性蛋白含量、SOD和CAT活性以及营养吸收的影响。结果表明：(1)低浓度的草甘膦异丙胺盐和敌敌畏可以促进球形棕囊藻和赤潮异弯藻的生长,高浓度时表现出不同程度的抑制效应。两种农药对两种微藻产生毒物刺激效应的作用浓度存在差异。赤潮异弯藻对于两种有机磷农药均较为敏感,而球形棕囊藻对于两种有机磷农药的耐受性较强。(2)两种农药对海洋微藻的叶绿素a含量有显著影响,叶绿素a含量的变化趋势与藻细胞生长趋势一致,表现出在低浓度有机磷农药处理(<1 mg·L-1)下为促进效应,高浓度有机磷农药处理下藻体叶绿素a含量下降。(3)球形棕囊藻和赤潮异弯藻的抗氧化酶活性显著受两种有机磷农药浓度的影响,两种藻的SOD和CAT活性在草甘膦异丙胺盐作用下均呈现出低浓度促进和高浓度抑制的现象,并且SOD活性随着农药浓度增大逐渐降低,球形棕囊藻的CAT活性在0.001mg·L-1浓度处理下最高,赤潮异弯藻的CAT活性在0.1 mg·L-1浓度处理下最高；在敌敌畏作用下,两种微藻的SOD和CAT活性在24 h呈现出低浓度促进高浓度抑制的现象,但藻液培养到了48 h以后较高浓度(≥1 mg·L-1)敌敌畏处理组的抗氧化酶活性仍然超过对照组。(4)在低浓度有机磷农药草甘膦异丙胺盐和敌敌畏处理下,球形棕囊藻和赤潮异弯藻培养液中的无机磷和无机氮浓度均出现了显著降低,而在高浓度草甘膦异丙胺盐处理组,两种赤潮藻对培养液中磷酸盐和硝酸盐的消耗量均有显著减少。更多还原

【Abstract】 Setting up 6 different mass concentrations 0,0.001,0.01,0.1,1 and 10 mg·L-1 of Glyphosate-isopropylammonium and DDVP, the growth rate, content of pigment, content of protein, activities of two antioxidant enzymes (SOD, CAT) and contents of inorganic P and N of red-tide species Phaeocystis globosa and Heterosigma akashiwo were measured in order to reveal the hormesis effect of organophosphorus pesticide in marine microalgae, and understand the laws of homesis induced by organophosphorus pesticides. The results showed:(1) Glyphosate-isopropylammonium and DDVP in low concentrations stimulated the growth of Phaeocystis globosa and Heterosigma akashiwo, while the growth of marine microalgae were restrained to different degrees under high concentrations of organophosphorus pesticides. There were significant concentrations and timing differences in the hormesis induced by organophosphorus pesticides in microalgae. Heterosigma akashiwo is more sensitive to two kinds of organophosphorus pesticides, and Phaeocystis globosa was tolerance stronger to organophosphorus pesticides. (2) Organophosphorus pesticides had significant impact on the content of chlorophyll-a. The variation trend of chlorophyll-a was consistent with the growth of microalgae, which showed inductive effect in low concentrations (<1 mg·L-1) while reduced the content of chlorophyll-a in high concentrations. (3) Antioxidant enzyme of Phaeocystis globosa and Heterosigma akashiwo were significantly affected by organophosphorus pesticides. Organophosphorus pesticides in low concentrations stimulated the SOD and CAT activities, while in high concentrations restrained the activities. Meanwhile, SOD activity decreased with the increasing concentration of pesticides. The highest CAT activity of Phaeocystis globosa was in the concentration of 0.001 mg·L-1 while Heterosigma akashiwo was in 0.1 mg·L-1. Under the treatments of DDVP, SOD and CAT activities of two kinds of microalgae showed hormesis effect in 24 hours, to 48 hours, the enzyme activities recovered at higher concentrations (≥1 mg·L-1). Antioxidant enzyme of Phaeocystis globosa and Heterosigma akashiwo were tolerance stronger to DDVP, and SOD was more sensitive to contamination. (4) Low concentrations of Glyphosate-isopropylammonium and DDVP accelerated the absorption of inorganic P and N. Meanwhile, there were higher inorganic P and N contents in the culture medium under higher concentrations of Glyphosate-isopropylammonium.更多还原