斜生栅藻对振荡和磷胁迫的生理生化响应

为了探讨水文条件的变化对常见绿藻水华发生的潜在影响,实验以斜生栅藻为材料,研究了不同水流状态及磷浓度对其生长及磷利用策略的影响。实验分别设置静止条件(0 r/min)、低振荡条件(90 r/min)和高振荡条件(120 r/min),同时设置磷限制(0.2 mg/L)和磷充足(2 mg/L)两组磷浓度,整个实验过程为3周。实验过程测定的指标为:比生长速率、胞外碱性磷酸酶活性、叶绿素a含量以及磷吸收动力学参数。实验结果表明:(1)同静止条件相比,低振荡和高振荡条件均能显著降低斜生栅藻的比生长速率,但是两种不同磷浓度下其比生长速率却无显著性差异。(2)在实验第21天时,振荡条件培养下,斜生栅藻的胞外碱性磷酸酶活性显著高于静止条件培养,与此相反,胞内磷浓度却显著高于静止条件。(3)在磷限制条件下斜生栅藻的叶绿素a含量显著降低,同时两种振荡条件培养均使其在磷充足条件下叶绿素a含量降低。(4)通过磷吸收动力学参数的比较,静止条件培养的斜生栅藻对磷的亲和力高于其在振荡条件下。由此可见,斜生栅藻适应于静止无扰动且磷营养丰富的水体,随着水体中磷浓度进一步升高,静止和水流缓慢的水体存在导致像斜生栅藻这一类绿藻发生水华的风险。

PHYSIOLOGICAL AND BIOCHEMICAL RESPONSES OF SCENDESMUS OBLIQUUS TO PHOSPHORUS AND TURBULENCE STRESS

In order to explore the potential effect of changing hydrological regimes on the green algae blooms,the effect of different levels turbulences on the growth and phosphorus(P) strategy of Scendesmus obliquus were studied.This experiment,lasting for 3 weeks,was designed with 3 levels turbulences,no turbulence(0 r/min),light turbulence(90 r/min)and high turbulence(120 r/min),combined with P-limit condition(0.2 mg/L) and P-replete condition(2 mg/L).The parameters determined during the experiment were listed as ...