邻苯二甲酸二丁酯对三角褐指藻的生态毒性效应

为了研究邻苯二甲酸二丁酯（DBP）对海洋微藻的生态毒性效应,选择三角褐指藻（Phaeodactylum tricornutum）作为受试对象,设置7个DBP质量浓度处理,即丙酮对照组、2.5、3、3.5、4、5和7.5mg·L-1,测定了三角褐指藻的生长、光合色素质量浓度和叶绿素荧光特性等指标。结果表明：DBP各暴露组对三角褐指藻的生长均有显著抑制作用,三角褐指藻不能耐受7.5mg·L-1的DBP,当DBP质量浓度为5mg·L-1时,三角褐指藻在前2天几乎没有生长,从第3天开始恢复生长,并很快进入指数生长期;叶绿素a、c及类胡萝卜素质量浓度也随着DBP暴露浓度的增大而逐渐降低;随着DBP暴露浓度的升高,三角褐指藻光系统Ⅱ（PSⅡ）的最大光能转化效率（Fv/Fm）、PSⅡ的潜在活性（Fv/F0）、实际光能转化效率（Yield）和光合电子传递效率（ETR）均降低,但与对照组相比,低质量浓度处理组（≤4mg·L-1）,各指标下降不明显,而5mg·L-1的实验组在胁迫12h后,Fv/Fm、Fv/F0、Yield、ETR逐渐上升,其参数值甚至超过其它处理组。

The ecological toxic effects of dibutyl phthalate on Phaeodactylum tricornutum

In order to study the ecological toxic effects of DBP on the marine microalgae,Phaeodactylum tricornutum was exposed to DBP at these seven concentrations,namely,acetone control,2.5,3,3.5,4,5 and 7.5 mg·L-1.Its growth rate,photosynthetic pigment contents and chlorophyll fluorescence were measured.The research revealed that the exposure of DBP had inhibition effect on the growth of P.tricornutum,which could not tolerate DBP of 7.5 mg·L-1.When the concentration of DBP was 5 mg·L-1,P.tricornutum had hardly grown for the first two days.It,however,began to grow again on the third day,and soon entered the exponential growth phase.The similar effects also occurred to chlorophyll a,chlorophyll c and carotenoids.That is,with the increase of DBP concentrations,the contents of chlorophyll a,c and carotenoids were gradually reduced.As DBP concentrations rose,the maximal photochemical efficiency of PSII（Fv/Fm）,the potential activity of PSII（Fv/F0）,the actual photochemical efficiency（Yield） as well as the electron transport rate（ETR） all declined.But the similar change had not obviously happened to the low concentration treatment groups（≤4 mg·L-1）,compared with the control group.While,after 12 hours of DBP stress,Fv/Fm,Fv/F0,Yield and ETR of the experimental group of 5 mg·L-1 were gradually increased,with the parameter values even exceeding the other treatment groups.