Effect Of Environmental Factors On Physiology, Growth And Biochemical Compositions Of Gracilaria Tenuistipitata

The high value of Gracilaria tenuistipitata for human food, abalone feed and agar production has led the development of farming systems in the coastal waters in China. It has great significance to ameliorate Eutrophication in the water, prevent red tide in the sea.In the present study, Gracilaria tenuistipitata (for short"Gracilaria")was selected as the tested plant,This paper examines effect of environmental factors (Diffetent levels of nitrogen,Diffetent levels of ammonium/anitrate nitrogen ratio,different P/N ratios)on the physiology, growth and levels of biochemical compositions of Gracilaria under the different indoor conditions.Under the low nitrogen condition (0,10μmol/L)or high nitrogen condition(60,80μmol/L);the low ammonium condition (0,2.5μmol/L)or high nitrogen condition(10,20,40μmol/L);the low ammonium /anitrate nitrogen ratio(1/35,1/7) or high ammonium/anitrate nitrogen ratio(3/7,4/7); the low P/N ratios (1/32)or high P/N ratios(1/8,1/4), The contents of PE,Cha,protein and the growth were both low.Under the condition that anitrate nitrogen20μmol/L; ammonium5μmol/L; ammonium/anitrate2/7(TIN20mol/L); P/N ratio1/16(TIN20or40mol/L), The contents of PE,Cha,protein and the growth were both the best..MDA content in levels of Gracilaria, Activities of CAT,PODof Gracilaria and praline content of Gracilaria were all reduced firstly,then increased drastically. Activities of SOD was opposite.Under the condition that anitrate nitrogen20μmol/L; ammonium5μmol/L; ammonium/anitrate2/7(TIN20mol/L); P/N ratio1/16(TIN20or40mol/L),The Activities of SOD and NR (expet ammonium ) were highest while MDA content were lowest.The objective of this study was to investigate the effect of environmental factors on the physiology, growth and levels of biochemical compositions of Gracilaria under the different indoor conditions. Form this study we can discuss the mechanism on the uptake of N, P, Expound. It has great significance to environmental protection of offing...