海马齿对氮、磷吸收利用速率的初步研究

为探讨海马齿对N、P营养元素的利用效率，在实验室条件下研究了海马齿对不同浓度N、P及其不同形态N的吸收速率。结果表明：（1）在适宜范围内，海马齿对氮、磷的吸收速率随介质中氮、磷浓度的升高而升高，差异显著(P<0.05)。在氮浓度为100 μmol/L时，氮吸收速率最大，为11.11 μmol/g?d；在磷浓度为10 μmol/L时，磷吸收速率最大，为0.74 μmol/g?d。（2）不同氮磷比及氮浓度下，海马齿对氮的平均吸收量仅在氮磷比1：1和5：1组差异显著(P<0.05)，其余组差异不显著；不同氮磷比及氮浓度下，海马齿对磷的平均吸收量差异显著(P<0.05)。氮最大吸收速率发生在氮浓度为50 μmol/L、氮磷比为50：1时，而磷的最大吸收速率发生在氮浓度为50 μmol/L、氮磷比为10：1时。（3）海马齿对NH4+-N的吸收速率随着NH4+-N和NO3－-N比的降低而加快，对NO3－-N的吸收速率随着NH4+-N和NO3－-N比的降低而减慢，差异显著。海马齿对TIN、PO43--P吸收速率呈折线变化趋势，TIN的吸收速率在NH4+-N/ NO3－-N为1：2处存在最大值，PO43--P的吸收速率在NH4+-N/NO3－-N为1：10处存在最大值。

The preliminary study of Sesuvium portulacastrum on the nitrogen and phosphorus absorption rate

In order to discuss the utilized efficiency of N and P by Sargassum portulacastrum . The preliminary study on the uptake rates of N and P by Sargassum fusiforme at the different concentrations, and different chemical combination of N and P were made under laboratory conditions. The results showed that： （1） At the suitable levels of concentrations, the uptake rates of N and P by Sesuvium portulacastrum ’ s increased with the increase concentrations of N and P in the media, and it was significantly different （ P〈 0.05）. When the N concentrations were at 100 μmol/L, uptake rates of N by Sesuvium portulacastrum reached the maximum value, and the maximum value was 11.11 μmol/（g·d）; when the P concentrations were at 10 μmol/L, the uptake rates of P by Sesuvium portulacastrum also reached the maximum value, the maximum value of P was 0.74 μmol/（g·d）. （2） At the different ratios of N to P and different N concentrations, the average uptake rates of N were not significantly different except at the ratio 1：1 and 5：1 （ P〈 0.05）; but at the different ratios of N to P and different N concentrations, the average uptake rates of P were significantly different （ P〈 0.05）. The maximum uptake rates of N by Sesuvium portulacastrum occurred at the N concentrations of 50 μmol/L and the ratios 50：1 （N：P）; and the maximum uptake rates of P by Sesuvium portulacastrum occurred at the N concentrations of 50 μmol/L and the ratios 10：1 （N：P）. （3） The uptake rates of NH 4 ＋ -N by Sesuviumportulacastrum increased with the reduction ratios of NH 4 ^＋ -N and NO 3 ^-N, while the uptake rates of NO 3^ -N by Sesuvium portulacastrum decreased with the reduction ratios of NH 4^ ＋ -N and NO 3^ -N, and they all were significantly different （ P〈 0.05）. The trend of the uptake rates of TIN and PO 4 ^3-P were broken line. The maximum uptake rates of TIN occurred at the ratios1：2 （NH 4 ^＋ -N： NO ^3 -N）, and the maximum uptake rates of PO 4 ^3-P occurred at the ratios1：10 （NH 4^ ＋ -N： NO 3^ -N）.