中文摘要：

近半个世纪以来,近海富营养化问题日益突出,微藻对C、N、P的吸收容易偏离Redfield比,自身元素组成受到影响。本文探究了在正常、低N/P和高N/P培养条件下,三角褐指藻（Phaeodactylum tricornutum）和中肋骨条藻（Skeletonema costatum）的元素（C、N、P）组成和其所在培养液营养盐含量的变化。结果表明：两种硅藻培养液的DIN、DIP和DIN/DIP在三处理组中,随时间的变化趋势不同;N/P比失衡的培养条件影响了两种硅藻的C/P、C/N和N/P值。高N/P比条件下,C/P值较对照组大幅度增加;低N/P比条件下,C/N值较对照组大幅度增加。而且,三角褐指藻各实验组的C、N、P化学计量比较中肋骨条藻表现出更强的稳定性;同种硅藻在N/P比失衡的培养条件下,P含量的变化幅度均大于N含量,表现出了更强的不稳定性。上述研究为营养限制对生物地球化学循环的影响的研究提供了重要的基础数据。

英文摘要：

Coastal eutrophication has become a serious problem in the last nearly 50 years. Absorption of C, N and P by microalgae would cause changes in chemical composition of algae body. The elemental composition would deviate from the Redfield ratio, and ultimately, cause a remarkable impact on nutrient structure of the ocean. We conducted an experimental culture for diatoms Skeletonema costatum and Phaeodactylum tricornutum under normal, low N/P, and high N/P conditions in 5 and 15 days. Results show that imbalanced N/P ratio of culture medium changed the C/P, C/N, and N/P ratios in diatom body, and so did in the culture media in DIN and DIP over time in a same pattern. The elemental composition of P. tricornutum showed greater stability than that of S. costatum; and N content showed greater stability than P content. The results may provide basic and referential data for the research on how nutrition limitation affects the biogeochemical cycling.