温度、光强和营养史对羊栖菜无机磷吸收的影响

为了探讨温度、光照和营养史对羊栖菜（Hizikia fusiforme）无机磷吸收的影响，在不同条件下培养藻体，于第0小时、第0.5小时、第1小时、第2小时、第4小时、第6小时和第9小时分别测定培养海水中磷（P）浓度，以此来计算藻体对P的吸收速率。培养条件设置为10℃、20 ℃和30 ℃3个温度梯度；0、1 500 lx和6 500 lx 3个光强梯度；营养史通过藻体在不同营养盐浓度下培养96 h后获得，其中不同P营养史设0、5 μmol·L-1和50 μmol·L-1 3个梯度，不同氮（N）营养史设0、10 μmol·L-1和200 μmol·L-13个梯度。结果表明, 羊栖菜对P的吸收速率在20 ℃时达到最大值（0.197±0.005） μmol·（h·g）-1，在10 ℃时最小值为（0.105±0.001） μmol·（h·g）-1；随着培养光强的升高，P吸收速率逐渐递增；随着营养史中P饥饿程度的增加，P的吸收速率递增；而不同N营养史处理的藻体，无氮（0 μmol·L-1）和低氮（10 μmol·L-1）处理之间无显著差异，高氮营养史（200 μmol·L-1）的藻体具有最高的P吸收速率。

Effects of temperature, irradiance level and nutritional history on the uptake of inorganic phosphorus in Hizikia fusiforme

To investigate the effects of temperature, irradiance level and nutritional history of nitrogen or phosphorus on inorganic phosphorus uptake in Hizikia fusiforme, we cultivated thalli under different conditions , measured the concentration of inorganic phosphorus in media at 0, 0.5th, 1st, 2nd, 4th, 6th and 9th hour, and determined the uptake rate. We set the temperature at 10 ℃, 20 ℃ and 30 ℃, and irradiance levels at 0, 1 500 lx and 6 500 lx in different experiments respectively. Different nutritional histories were obtained by growing thalli at different concentrations of nutrient for 96 h, including 3 levels of phosphorus （0, 5 μmol·L-1and 50 μmol·L-1） and 3 levels of nitrogen（0, 10 μmol·L-1 and 200 μmol·L-1）, respectively. The results show that the uptake rate of inorganic phosphorus reaches maximum at 20 ℃, while the minimum at 10 ℃. With the enhancement of irradiance level, uptake rate increases. Thalli with nutritional history of lower phosphorus concentration show a higher uptake rate of phosphorus, and vice versa. For different nitrogen histories, higher uptake rate is found in alga with higher nitrogen history, and there is no significant difference between 0 and 10 μmol·L-1 nitrogen histories.