三苯基锡对假微型海链藻(Thalassiosira pseudonana)的生长抑制及温度的影响

在我国近岸海域环境中,三苯基锡分布十分广泛。本研究以假微型海链藻(Thalassiosira pseudonana)为目标物种,研究了4个不同温度条件下(10℃、15℃、25℃与30℃)三苯基锡暴露对其细胞生长以及光合作用参数(Fv/Fm与ФII)的影响。结果表明,假微型海链藻的细胞生长速率在高温与低温条件下均显著下降,而光合作用参数仅在30℃条件下受到显著影响。在暴露温度为10℃、15℃、25℃与30℃时,三苯基锡(triphenyltin,TPT)对假微型海链藻的生长抑制IC50值分别为1.81、1.69、1.09与0.73μg·L-1。TPT对假微型海链藻光合作用抑制的IC50随着温度的升高呈降低趋势。Two-way ANOVA分析结果显示,温度与三苯基锡的相互作用显著影响假微型海链藻的光合作用。上述研究结果可以为了解不同温度下三苯基锡对海洋微藻的毒性效应提供科学依据。

Temperature-Dependent Toxicities of Triphenyltin to the Marine Diatom Thalassiosira pseudonana

Triphenyltin (TPT) is a widely distributed pollutant in coastal environment in China.In the present study,its toxicity to the growth and photosynthesis of the marine diatom Thalassiosira pseudonana at different temperatures (i.e.,10 ℃,15 ℃,25 ℃ and 30 ℃) were investigated.Results showed that TPT had significant inhibition effect on both the growth and the photosynthesis at 30 ℃,while the photosynthesis was not affected by TPT at relative low temperatures.The IC50 values of TPT for growth inhibition tests were 1.81,1.69,1.09 and 0.73 μg· L-1 at 10 ℃,15 ℃,25 ℃ and 30 ℃,respectively.Similarly,the IC50 values for photosynthesis inhibition test decreased with the increase of temperatures.Two-way ANOVA analysis revealed that there was significant interaction effect of temperature and TPT concentrations on the growth and photosynthesis of T.pseudonana.Temperature-dependent toxicity patterns were species-specific.The pattern observed for T.pseudonana in this study was similar as that for the invertebrates (i.e.,the marine copepod Tigriopus japonicus and the rotifer Brachionus koreanus),but it was different from the marine medaka Oryzias melastigma.The overall results of the present study can provide useful references for understanding the toxic effect of TPT on the algae species under different temperatures.