中文摘要：

研究了2种大型海藻石莼（Ulva pertusa）和江蓠（Gracilaria lemaneiformis）对2种赤潮微藻：东海原甲藻（Prorocentrum donghaiense）和塔玛亚历山大藻（Alexandum tamarense）生长的影响以及2种微藻之间的相互作用，结果发现：①在大藻（石莼或江蓠）一微藻（东海原甲藻或塔玛亚历山大藻）的共培养体系中，石莼和江蓠均能明显影响与其共培养的微藻的生长，石莼对微藻生长的影响强于江蓠的作用．②在东海原甲藻塔玛亚历山大藻的双藻培养体系中，东海原甲藻的生长受到明显的抑制作用，最终被完全灭杀；体系中塔玛亚历山大藻的生长未受到明显的影响．另外，塔玛亚历山大藻的培养液滤液能明显抑制东海原甲藻的生长，但东海原甲藻滤液对塔玛亚历山大藻的生长几乎没有影响．实验室条件下模拟二者相互作用的结果显示，塔玛亚历山大藻对东海原甲藻的抑制作用是其被后者抑制作用的17倍左右．③在大藻（石莼或江蓠）-东海原甲藻-塔玛亚历山大藻的多藻培养体系中，东海原甲藻和塔玛亚历山大藻的生长变化与它们在共培养体系中的变化非常类似．半数致死时间（LT50）法的检测结果显示：多藻培养体系对东海原甲藻的联合作用是协同作用，而对塔玛亚历山大藻的作用是相加作用．

英文摘要：

We studied the effects of fresh tissue and culture medium filtrate of Ulva pertusa （Chlorophyta） and Gracilaria lemaneiforrnis （Rhodophyta） on growth of 2 causative bloom species： Prorocentrurn donghaiense and Alexandurn tarnarense, in laboratory conditions. Both U. pertusa and G. lernaneiforrnis, especially their fresh tissues, significantly interfered with the growth of the co-cultured microalgae. P. donghaiense could be completely killed in the blalgal culture, but growth of A. tarnarense in it was little affected. Simultaneous assay on the effects of culture medium filtrates showed that the culture filtrate of A. tarnarense had alglcidal effect on P. donghaiense, while that of P. donghaiense had little effect on growth of A. tamarense. We simulated the interactions between P. donghaiense and A. tarnarense in the bialgal culture by using a mathematical model. Results show that the effect of P. donghaiense inhibited by A. tarnarense is about 17 times larger than the inhibitory effect of P. donghaiense exerted on A. tarnarense. The joint effects of multialgal cultures on microalga were analyzed. Results present that the multialgal cultures of either U. pertusa or G. lemaneiforrnis on P. donghaiense are synergism, and the joint effect of U. pertusa and P. donghaiense on A. tarnarense is additional. However, it was difficult to determine the joint effects of G. lernaneiforrnis and P. donghaiense on A. tamarense. Results suggest that allelopathy is the most likely reason responsible for the results obtained in this paper.