DOI: 10.15986/j.1006-7930.2019.01.002
磷(P)常被认为是水体富营养化的限制因子之一,对藻类生长及光合作用有很大的影响.以普通小球藻(Chlorella vulgaris)为实验对象,测定低磷浓度下小球藻的生物量、营养盐的吸收利用和光合效率的变化情况.结果表明:试验氮磷浓度范围(NO3-N:1～8 mg/L; PO43-P: 0.2～1.0 mg/L),小球藻生物量受初始磷浓度的影响较大,P=0.4 mg/L时小球藻生长最好.在实验磷浓度范围内,初始供磷水平影响小球藻对外源氮的吸收利用,氮(N)的吸收量会随着初始供磷水平的提高而增大.在固定磷浓度条件下,提高氮浓度,小球藻叶绿体中PSⅡ反应中心的最大光合作用效率(Fv/Fm)均值也会随之增加,发生磷胁迫的Fv/Fm阈值为0.18～0.24.Fv/Fm值可综合表征小球藻的生长指标、氮和磷的吸收利用率并且研究营养盐胁迫下藻类的生长.
Phosphorus(P)is usually considered as one of the limiting factors of water eutrophication, and it has has a great influence on growth and photosynthesis of microalgae. During the experiment, Chlorella vulgaris was selected as the research object, the biomass growth, absorption and utilization of nitrogen and phosphorus and photosynthetic efficiency were measured at low phosphorus content. The results revealed that within the scope of NO3-N: 1～8 mg/L and PO43-P: 0.2～1.0 mg/L phosphorus was the main limiting factor to influence the growth of C. vulgaris. The optimal supply of phosphorus content for C. vulgaris growth was 0.4 mg·L-1 .Within the range of experimental phosphorus content, absorption of exogenous nitrogen(N)increased with the increment of initial phosphorus content. When the phosphorus content was determined, the average value of Fv/Fm increased with increment of the nitrogen content, the threshold of Fv/Fm for phosphorus stress of C. vulgaris was 0.18～0.24. Fv/Fm had a significant correlation with biomass, the absorption and utilization of nitrogen and phosphorus, using Fv/Fm can synthetically characterize algae growth status and study on the growth of microalgae under nutrient stress.
