在实验室培养条件下，利用流式细胞仪从细胞生长、细胞大小、细胞膜完整性、酯酶活性等方面分别研究了三角褐指藻(Phaeodactylum triconutum)滤液提取物对东海原甲藻(Prorocentrum donghaiense)和盐藻(Dunaliella salina)为期6d生物培养过程中生理特性的影响。结果表明，三角褐指藻滤液乙酸乙酯提取物对东海原甲藻表现出强烈的生长抑制作用，荧光检测显示，其能刺激细胞体积的增大，导致部分藻体细胞膜受损，酯酶活性在短时间内增强，随后受到显著抑制。而提取物对盐藻的生长抑制并不明显，盐藻细胞体积没有受到影响，细胞膜保持了高度完整，酯酶活性在第6天时才受到抑制作用。以上分析表明，东海原甲藻对三角褐指藻滤液乙酸乙酯提取物更加敏感，特殊的细胞内部结构特征有利于化感物质进入东海原甲藻的体内，直接导致藻细胞的死亡。化感物质引起的不同的生理响应中，酯酶活性指标具有更好的敏感性，是在环境压力下生物自我保护的一种应急方式。

To investigate allelopathic effects of extracts from the filtrate of Phaeodactylum triconutum on growth and physiology of bloom-forming Prorocentrum donghaiense and Dunaliella salina, the cell density, cell size, membrane integrity and esterase activity were determined by the flow cytometry during a 6 d exposure test in laboratory. The results suggested that the growth of P. donghaiense was significantly inhibited by ethyl acetate extracts from the filtrate of P. triconutum. With the ethyl acetate extracts treatments, the cell size increased and the part of the algae membrane integrity was damaged, at the same time esterase activity significantly increased within a short time and was inhibited subsequently. However, the growth of D. salina was not inhibited by extracts from the filtrate of P. triconutum significantly. Both the cell size and membrane integrity was not inhibited, compared with the control cultures, the extracts induced negative effects on the esterase activity after 6 days exposure. These results confirmed that P. donghaiense was more sensitive to the allelochemical contained in the ethyl acetate of P. triconutum. Many P. donghaiense cells rapidly died and disappeared which be caused by the special internal structure of cells that the allelochemicals could easily enter the P. donghaiense cells. Esterase activity was the most sensitive parameter to evaluate the influence of the P. triconutum allelochemical on P. donghaiense, a kind of emergency mode of biological self-protection under environmental pressure.