氮浓度对盐生杜氏藻和纤细角毛藻叶绿素荧光特性及生长的影响

EFFECTS OF DIFFERENT NITROGEN CONCENTRATIONS ON THE CHLOROPHYLL FLUORESCENCE AND GROWTH OF DUNALIELLA SALINA AND CHAETOCEROS GRACILIS

在温度为(23±1)℃,盐度为31,光照强度为5000lx的条件下,用含有不同氮浓度(0μmol/L,55μmol/L,440μmol/L,880μmol/L,1760μmol/L,7040μmol/L)的培养基对中国海洋大学微藻种质库保存的盐生杜氏藻(Dunaliella salina)和纤细角毛藻(Chaetoceros gracilis)进行培养,研究两种微藻在一次性培养过程中,不同氮浓度对其PSⅡ最大光能转化效率(Fv/Fm)、叶绿素含量以及细胞密度的影响。单因子方差分析结果表明,氮浓度对两种微藻的光合作用及生长均有显著影响(P<0.05)。两种微藻的Fv/Fm比值、叶绿素含量以及细胞密度均随着起始氮浓度的增加而增加,在1760μM时达到最大值,其后随着起始氮浓度的增加,上述指标反而下降。多重比较结果表明,盐藻和纤细角毛藻进行光合作用和生长的最适氮浓度都为1760μmol/L。。

The effects of different nitrogen concentrations （0μM, 55μM, 440μM, 880μM, 1760μM and 7040μM） on the maximal photochemical efficiency of PS Ⅱ （Fv/Fm）, chlorophyll content and cell density of the two marine microalgae, Dunaliella salina and Chaetoceros gracilis, are investigated. The algae were obtained from the Microalgae Culture Center （MACC）, Ocean university of China. The cultures were grown at 23±1℃, the salinity was adjusted to 31 by using distilled water, and the light intensity was 50001x. One-way analysis of variance showed that nitrogen concentration has significant effects on the photosynthesis and growth of the two microalgae. The value of Fv/Fm, chlorophyll content and cell density of the two microalgae all increased with the increase of nitrogen concentration and reached their highest values at 1760 M, then all the above quantities decreased with the increase of nitrogen concentration. Multiple comparison tests showed that the optimal nitrogen concentrations for the photosynthesis and growth of D. salina and C. gracilis are both 1760μM.