海洋卡盾藻与三种典型海洋硅藻的种间竞争研究

以海洋卡盾藻和典型硅藻旋链角毛藻、三角褐指藻、中肋骨条藻为研究对象，采用室内单独培养和混合培养方法，研究了不同营养条件和不同初始密度下海洋卡盾藻与硅藻的生长和种间竞争效应。结果表明，在富营养化的f/2培养基下，海洋卡盾藻的最大细胞密度不受起始细胞密度的影响；而在营养盐限制下，最大细胞密度仅为f/2培养基的15.4%。与硅藻共培养中，海洋卡盾藻的生长被显著抑制，特别是在f/2培养基中，海洋卡盾藻的生长被完全抑制，培养10~16 d后海洋卡盾藻细胞逐渐消亡。与之相反，富营养的f/2培养基下，在与海洋卡盾藻共培养中的旋链角毛藻和三角褐指藻的生长未受到明显影响，而中肋骨条藻则受到影响，最大细胞密度不到单独培养的50%。而在营养盐限制下，三种硅藻的生长均受到海洋卡盾藻的明显影响，同时海洋卡盾藻的生长也受到硅藻的明显抑制。研究结果说明，营养盐丰富的条件下，小型硅藻可在与海洋卡盾藻的种间竞争中占据优势，但是硅藻爆发生长导致营养盐含量急剧下降，可能会有利于非硅藻类的生长。

Interspecies competition between Chattonella marina and three typical marine diatoms

Growth and interspecies competition were studied between harmful algal bloom species Chattonella marina and three typical diatoms (Chaetoceros curvisetus, Phaeodactylum tricornutum, and Skeletonema costatum) under different nutrient conditions and initial cell densities using batch cultures.Results showed that the maximum cell densities of C.marina were not affected by the initial cell density in enriched f/2 cultures.However, the maximum cell density was significantly reduced in nutrient limitation, which was only 15.4% of that in f/2 cultures.The growth of C.marina was significantly inhibited in co-cultures with diatoms, which resulted 100% death of C.marina after 10-16 days in co-cultures under f/2 medium.On the contrary, the growth of C.curvisetus and P.tricornutum were not significantly influenced in co-cultures of C.marina under f/2 medium.While the growth of S.costatum was significantly inhibited in co-cultures, the maximum cell density was less than 50% of those in mono-cultures.However, the growth of C.marina and all of the three diatom species were significantly inhibited in co-cultures under nutrient restriction.Results of this study suggested that these small diatoms might have competitive advantages over C. marina under nutrient enriched conditions, however, rapid decline in nutrient concentration caused by the outbreak of diatom blooms might be beneficial to the growth of non-diatoms.