草甘膦对可食用蓝藻葛仙米生长和生理的影响(英文)  

EFFECTS OF ACUTE GLYPHOSATE EXPOSURE ON THE GROWTH AND PHYSIOLOGY OF NOSTOC SPHAEROIDES,AN EDIBLE CYANOBACTERIUM OF PADDY RICE FIELDS

作　　者：阮祚禧[1] Murray T.Brown 

机构地区：[1]汕头大学科技中心海洋生物研究所,汕头515063 [2]School of Biological Sciences,University of Plymouth,Drake Circus,Plymouth PL4 8AA,United Kingdom

出　　处：《水生生物学报》2008年第4期462-468,共7页Acta Hydrobiologica Sinica

基　　金：the National Natural Science Foundation of China(No.40676063 and 30670396);Natural Science Foundation of Guangdong Province(06105649)Shantou University to MTB is grate-fully acknowledged.

摘　　要：葛仙米(N.sphaeroides)的产量和产地面积逐年减少,这可能与当地广泛使用除草剂草甘膦有关。为此,本文测定了不同浓度(0.15、0.30、0.45、0.6mmol/L)的草甘膦处理的葛仙米的颗粒大小、干重、叶绿素荧光、叶绿素浓度。所有测量参数与浓度和时间显著相关:0.15mmol/L处理组的颗粒直径较对照组小15%(2d后);叶绿素a浓度和最大量子产率(Fv/Fm)在最高浓度组(0.6mmol/L)4d后开始受到影响;第8天,相对生长速率(以干重计算,大于0.15mmol/L)、光合作用活性(大于0.3mmol/L)均受显著抑制,其中0.15mmol/L处理组相对生长下降60%,而更高浓度处理组出现负生长,0.6mmol/L组藻体漂白死亡。结合实验结果,文章讨论了草甘膦的毒性机理及其对葛仙米(N.sphaeroides)的潜在影响。The productivity of Nostoc sphaeroides,an edible cyanobacterium found in paddy rice fields has declined in recent years. It may relate to the increased application of agricultural herbicides. To assess the impact of glyphosate exposure （0. 15,0.30,0.45 and 0.6 mmol/L Gly acid） , the effects on colony size, dry biomass accumulation, chlorophyll a fluorescence （Fv/Fm） and chlorophyll a biosynthesis were investigated over an 8d period. All parameters were significantly inhibited in a concentration used and time dependent way. After 2d exposure to 〉0.15 mmol/L Gly colonies were approximately 15% smaller than the controls. After 4d exposure,chlorophyll a content and Fv/Fm were affected by the highest concentration used（0.6 mmol/L Gly）. By the 8d, chlorophyll biosynthesis and Fv/Fm were significantly inhibited by concentrations greater than 0. 15 and 0.3 mmol/L Gly,respectively. The 8d relative growth rates （RGRs） ,calculated for dry biomass,were significantly affected by all glyphosate treatments, there was a 60% reduction at 0.15 mmol/L Gly and negative RGRs at higher concentrations indicate a loss of biomass. Exposure to 0.6 mmol/L Gly was lethal with loss of colony integrity, bleaching of pigments and no photosynthetic activity by 8d. These results are discussed in terms of the mechanisms of toxicity and the potential implications for the long term sustainability of the N. sphaeroides resource.

关 键 词：除草剂 蓝藻 毒性 生长 叶绿素a荧光 

分 类 号：Q178.11[生物学—水生生物学]