Effect of P concentrations on chlorophyll fluorescence and growth of Chlorella sp.

The eutrophication had significant effects on the growth of marine algae which could induce the variation of ocean primary production. In this paper, Chlorella sp. was selected as target marine algae and cultured in the medium containing different P concentration, the effects of P concentration on variation of chlorophyll fluorescence, cell density and pigment content of Chlorella sp. were investigated. The Chlorella sp. was cultured under the light intensity of 4 000 lx, light/dark cycle of 12 h/12 h and (22±1) ℃ for 7 days, Fv/Fm, Fv/Fo, ФPSⅡ and ETR of the marine algae all presented the tendency of increased first and then decreased during the cultivation. P concentrations had significant effects on the photosynthesis and growth of Chloerlla sp. (P0.05), the 4 parameters were comparatively low in group containing lower P concentration(3.62 μmol/L), while this group obtained the highest qN value. Cell density and pigment content were the highest in group containing 36.21 μmol/L of P, multiple comparison tests showed that the optimal P contentrations for the growth of Chlorella sp. were 36.21 μmol/L.