The interaction effects of Cd~(2+),nitriate and phosphate concentrations on the growth and chlorophyll fluorescence charteristics of Dunaliella salina

The interaction effects of Cd2+,nitriate and phosphate concentration on the growth and chlorophyll fluorescence charteristics of Dunaliella salina were investigated in this paper.The results indicated that Cd2+,nitriate and phosphate concentration had significant effects on the photosynthesis and growth of Dunaliella salina(P0.05).The fluorescence parameters of Fv/Fm,Fv/Fo,Yield and rETR,cell density and relative chlorophyll content of Dunaliella salina were significant negative correlated with Cd2+ concentrations after 24 h.And the fluorescence parameters evidently decreased in Dunaliella salina under low nitriate concentration of 55 μmol/L,and it also caused the decrease of the cell density and relative chlorophyll content.Under high nitriate concentration(7 040 μmol/L),there was no significant difference in the chlorophyll fluorescence parameters.The fluorescence parameters(Fv/Fo,NPQ),cell density and relative chlorophyll content of Dunaliella salina got to the greatest values at normal nitriate concentration of 880 μmol/L,and the Dunaliella salina had more tolerance to Cd2+.The fluorescence parameters(except NPQ),cell density and relative chlorophyll content of Dunaliella salina remarkably decreased in Dunaliella salina under low phosphate concentration(2.27 μmol/L),which showed obvious phosphorus limitation.The chlorophyll fluorescence parameters,cell density and relative chlorophyll content reached the highest values at high phosphate of 290.40 μmol/L,and the Cd2+ stress to Dunaliella salina was lowest.