The effects of variable 5 N/P concentration levels and 4 N : P ratio levels of 3 N concentration levels, respectively, on uptake rates (SNUR and LNUR) and uptake efficiency (SNUE and LNUE) of N (TIN) and P (PO3/4 -P) by Gracilaria lichenoides for short-term (0-4h) and long-term (over a 24h period at 14th day) were studied. Meanwhile, ul-trastructure of cells of G. lichenoides cultivated in different N and P concentration for 14 day was observed. The results showed that optimal N : P ratio in culture media which SNUR and LNUR for N and P by G. lichenoides reached the highest value among different N/P concentrations (P<0.05) was 16:1. The reached maximum SNUR of N and P by G. lichenoides was respectively 12.85 and 0.79μmol/(gDW·h), when the N/P concentration in medium was 1200/75 and 960/60μmol/L, but the ultrastructure of chloroplasts of G. lichenoides cultivated in those N/P concentration for 14 day emerged some extent damage. The reached maximum LNUR of N and P by G. lichenoides were 4.23 and 0.31μmol/(gDW·h), respectively, when the N/P concentration in medium was 480/30μmol/L. The reached maximum SNUE and LNUE of N and P by G lichenoides was in the medium of N/P 60/3.75μmol/L, but decreased to the minimum SNUE and LNUE, respectively, was in the medium of N/P 1200/75μmol/L.%通过设置5个N/P浓度梯度和3个N浓度下的4个N:P梯度,进行了江蓠对N、P的短期(O-4h)和长期(第14天)吸收速率(SNUR和LNUR)以及短期和长期吸收效率(SNUE和LNUE)的研究,同时观察了5个N/P浓度梯度对江蓠细胞超微结构的影响.结果表明:N∶P比为16∶1时,江蓠对N、P的SNUR和LNUR均最大(P＜0.05); N/P为1200/75和960/60μmol/L浓度时,分别对N和P的SNUR最大,达12.85和0.79μmol/(gDW·h),但此N/P浓度下长期培养的江蓠叶绿体结构存在不同程度的损伤;而N/P浓度480/30μmol/L时,对N和P的LNUR均最大值4.23和0.31 μmol/(gDW·h).江蓠对N、P的SNUE和LNUE在介质N/P 60/3.75μmol/L时为最高,而在1200/75 μmol/L时为最低(P＜0.05).
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