不同氮磷浓度对米氏凯伦藻生长的影响

采用f／2培养基，NaNO3和NaH2PO4分别为氮源和磷源，分别研究了不同浓度的氮磷源（NaNO3：30、60、150、750、1275、3000mg／L，NaH2PO4：4．4、8．8、22、44、88、176mg／L）对米氏凯伦藻（Karenia mikimotoi MACC／D23）生长的影响．单因子方差分析结果表明，不同的氮、磷浓度对其相对生长率的影响均有显著性差异（P〈0．05）．多重比较结果表明：750mg／LNaNO3浓度组的相对生长率显著高于其他浓度组，22mg／LNail2PO4浓度组的相对生长率显著高于其他浓度组，88mg／L和176mg／LNail2PO4浓度组之间没有显著性差异．其最高细胞密度和相对生长率在NaNO3质量浓度为30-750mg／L时，随氮浓度的升高而升高，均在NaNO3质量浓度为750mg／L时达到最大值，分别为4．60×10^6mL^-1和0．608d^-1，而当NaNO3质量浓度大于750mg／L时，最高细胞密度和相对生长率随氮浓度的进一步升高而降低．当NaH2PO4质量浓度在4．4～8．8mg／L之间，最高细胞密度随磷浓度升高而升高，在8．8mg／L时达到最大值，为2．69×10^6mL^-1；当Nah2PO4质量浓度在4．4—22mg／L之间，相对生长率随磷浓度的升高而升高，在22mg／L时达到最大值．为0．568d^-1．之后随磷浓度的进一步升高而降低．

Effects of Nitrate and Phosphate Concentration on the Growth of Red Tide Species Karenia mikimotoi

The cell density and relative growth rate of Karenia mikimotoi MACC/D23, cultivated in f/2 medium under different concentration of NaNO3（30, 60, 150, 750, 1 275 and 3 000 mg/L）and NaHzPO4（4.4,8.8, 22, 44, 88 and 176 mg/L） were examined. One-way analysis of variance shows that different concentration of NaNO3 and NaH2PO4 had significant effects on the relative growth rate of K.mikimotoi （P〈0.05）. Multiple comparison tests show that the optimal NaNO3 and NaH2PO4 concentration in culture medium of K. mikimotoi under the experimental conditions is 750 mg/L and 22 mg/L respectively. The highest cell density and relative growth rate increase with NaNO3 concentration at 30- 750 mg/L, then decrease at 750 -3 000 mg/L, the highest value are 4.60×10^6mL^-1 and 0.608 d^-1 respectively. The highest cell density increase with NaH2PO4 concentration at 4.4 - 8.8 mg/L, then decrease with phosphate concentration, the highest value is 2.69×10^6mL^-1. The highest relative growth rate increase with NaH2PO4 concentration at 4.4 - 22 mg/L, then decrease with phosphate concentration, the highest value is 0.568 d^-1.