Algal allelopathy is a manifold ecological/physiological phenomenon that is focused on chemical interactions and autotoxicity. We investigated the allelopathic interactions between Karenia mikimotoi and Dunaliella sal...Algal allelopathy is a manifold ecological/physiological phenomenon that is focused on chemical interactions and autotoxicity. We investigated the allelopathic interactions between Karenia mikimotoi and Dunaliella salina in laboratory cultures based on different temperature （15℃, 20℃, and 25℃） and lighting （40,80, and 160 umol/（m2·s）） conditions. The growth of D. salina in bi-algae culture （1：1 size/density） was significantly restrained. The results of cell-free filtrate culture indicate that direct cell-to- cell contact was not necessary in interspecific competition. Further experimental results demonstrated that allelochemicals released from K. miMmotoi were markedly influenced by both temperature （P=0.013） and irradiance （P=0.003）, resulting in different growth characteristics olD. salina in filtrate mediums. Compared with the plateau period, K. mikimotoi exudates in the exponential phase had a stronger short-term inhibition effect on D. salina in normal conditions. A clear concentration-dependent relationship was observed in the effect of allelochemicals released from K. mikimotoi with low-promoting and high-repressing effects on D. Salina in a short time-scale. In addition, allelopathic substances remain stable and effective under high temperature and pressure stress. Many flocculent sediments adhering with D. salina cells were observed in all filtrate mediums, while the quantity and color depended on the original culture conditions.展开更多
基金Supported by the State Key Laboratory of Satellite Ocean Environment Dynamics(Second Institute of Oceanography,SOA)(No.SOED1418)the Public Science and Technology Research Funds Projects of Ocean(No.201305027)+1 种基金the National Natural Science Foundation of China(No.91128212)the Research Fund for the Doctoral Program of Higher Education of China(No.20110132120025)
文摘Algal allelopathy is a manifold ecological/physiological phenomenon that is focused on chemical interactions and autotoxicity. We investigated the allelopathic interactions between Karenia mikimotoi and Dunaliella salina in laboratory cultures based on different temperature （15℃, 20℃, and 25℃） and lighting （40,80, and 160 umol/（m2·s）） conditions. The growth of D. salina in bi-algae culture （1：1 size/density） was significantly restrained. The results of cell-free filtrate culture indicate that direct cell-to- cell contact was not necessary in interspecific competition. Further experimental results demonstrated that allelochemicals released from K. miMmotoi were markedly influenced by both temperature （P=0.013） and irradiance （P=0.003）, resulting in different growth characteristics olD. salina in filtrate mediums. Compared with the plateau period, K. mikimotoi exudates in the exponential phase had a stronger short-term inhibition effect on D. salina in normal conditions. A clear concentration-dependent relationship was observed in the effect of allelochemicals released from K. mikimotoi with low-promoting and high-repressing effects on D. Salina in a short time-scale. In addition, allelopathic substances remain stable and effective under high temperature and pressure stress. Many flocculent sediments adhering with D. salina cells were observed in all filtrate mediums, while the quantity and color depended on the original culture conditions.
