大气CO2浓度升高和氮加富对羊栖菜有关生理生化特征的影响

以褐藻门马尾藻科马尾藻属羊栖菜（Hizikia fusiformis）为试验材料，探讨了在2种氮（N）水平下，CO2浓度升高对羊栖菜生长、光合作用和生化组成的影响。试验设350和700 mol mol-12种CO2浓度水平，以及自然海水加入浓度0、500 mol L-1的NaNO3 2种N肥施用水平。结果表明，在自然海水培养的条件下，倍增CO2对羊栖菜生长、光合作用和生化组成的影响不明显。而在N加富海水中培养的藻体升高CO2较明显的抑制了藻体的生长，并且干重鲜重比、体内蛋白质和可溶性多糖的含量分别降低4.5%、15%、32%。这可能主要是由于N加富使藻体内NO2- 过多积累，而CO2升高使水体pH值降低，在藻体内形成HNO2产生的毒害作用。

Effects of increased atmospheric CO2and N supply on some physiological and biochemical traits in the economic brown seaweed,Hizikia fusiformis (Sargassaceae,Phaeophyta)

The marine macroalgae Hizikia fusiformis （Harvey） Okamura(Sargassaceae, Phaeophyta) was cultured under the condition of elevated atmospheric CO2and increased N supply to investigate the effects of increased CO2 concentration and N supply on the growth, photosynthesis, and other related physiological and biochemical traits in this species. The experiment was designed for two CO2 levels which was 350 and 700 molmol-1, and two NO-3 levels which was added 0, 500 molL-1 NaNO3 in seawater. The algae cultured under non-N-enriched seawater, elevated CO2 concentration had no significant effects on growth and biochemical traits. However, the algae cultured under N-enriched seawater, elevated CO2 could effectively depress the growth. The ratio of fresh weight（FW）to dry weight（DW）,the concentrations of soluble protein and soluble carbohydrate were decreased 4.5%, 15% and 32%. It suggested that increased N supply led to the accumulation of NO-2，and elevated CO2 concentration caused pH value to decrease. This condition was well to form HNO2, which is toxic effect on H.fusiformis.