Wang You, Yu Zhi-ming, Song Xiu-xian, Zhang Shan-dong
Key Laboratory of Marine Ecology & Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
Huan Jing Ke Xue. 2006 Feb;27(2):246-52.
We studied the effects of fresh tissue and culture medium filtrate of two species of macroalgae, Ulva pertusa (Chlorophyta) and Gracilaria lemaneiformis (Rhodophyta) on growth of Heterosigma akashiwo (Raphidophyceae) in co-culture. Both U. pertusa and G. lemaneiformis, and especially their fresh tissues, significantly impede the growth of H. akashiwo. Carbonate limitations and the presence of environment bacteria are not necessary for the negative effects of macroalgal on H. akashiwo. The simultaneous nutrient assays show that nitrate and phosphate are almost exhausted in the G. lemaneiformis co-culture system, but remain at acceptable levels in the U. pertusa system, when all cells of H. akashiwo are completely dead. When f/2 medium is supplied daily to G. lemaneiformis culture, the growth of H. akashiwo is greatly inhibited but not completely terminated. Furthermore, different amounts of fresh seaweed tissue, and culture medium filtrate prepared from different macroalgal concentrations are analyzed to determine their effects on the growth of H. akashiwo. The results show a positive correlation between the initial macroalgal concentration and the negative effects they exert on the co-cultured microalgae. Results suggest that the allelopathic effects of U. pertusa may be essential for negative effects on H. akashiwo; however, the combined roles of allelopathy and nutrient competition may be responsible for the negative effect of G. lemaneiformis the release of allelochemicals by U. pertusa.
我们研究了两种大型海藻——孔石莼（绿藻门）和龙须菜（红藻门）的新鲜组织及培养基滤液在共培养体系中对赤潮异弯藻（金藻门）生长的影响。孔石莼和龙须菜，尤其是它们的新鲜组织，均能显著抑制赤潮异弯藻的生长。碳酸盐限制和环境细菌的存在并非大型海藻对赤潮异弯藻产生负面影响的必要条件。同步营养分析表明，当赤潮异弯藻的所有细胞完全死亡时，龙须菜共培养体系中的硝酸盐和磷酸盐几乎耗尽，但在孔石莼体系中仍保持在可接受水平。当每天向龙须菜培养物中供应f/2培养基时，赤潮异弯藻的生长受到极大抑制，但并未完全停止。此外，分析了不同量的新鲜海藻组织以及由不同大型海藻浓度制备的培养基滤液对赤潮异弯藻生长的影响。结果表明，初始大型海藻浓度与其对共培养微藻产生的负面影响之间存在正相关。结果表明，孔石莼的化感作用可能是其对赤潮异弯藻产生负面影响的关键因素；然而，化感作用和营养竞争的共同作用可能是龙须菜对赤潮异弯藻产生负面影响的原因，孔石莼会释放化感物质。
