实验条件下原甲藻与中肋骨条藻种间相互作用研究

The Interactions between Prorocentrom micans and Skeletonema costatum in Laboratory Cultures

微藻化感作用是一种极其复杂的生理、生态学现象,其在解释微藻藻种分布、群落结构及种群动力学方向起着关键作用。选择我国典型常见赤潮优势种原甲藻(Prorocentrum micans)与中肋骨条藻(Skeletonemacostatum)作为对象,研究实验室共培养条件下2种微藻种间相互作用关系。结果表明:两者以1×104 cells/mL的密度接种共培养时,原甲藻的生长状况几乎没有显著变化(F=0.004 48,P=0.947 96>0.05),而共培养的中肋骨条藻被原甲藻强烈抑制致死(F=5.116 63,P=0.047 21<0.05)。Lotka-Volterra双藻竞争模型分析知,共培养条件下原甲藻的种间竞争能力大于中肋骨条藻的种间竞争能力。在去藻滤液实验中,灭菌处理及未经灭菌处理的原甲藻去藻滤液对中肋骨条藻的生长都没有显著影响(P>0.05);中肋骨条藻-原甲藻共培养体系的去藻滤液经灭菌处理及未经灭菌处理培养中肋骨条藻时,中肋骨条藻的生长也没有显著变化(P>0.05)。可见,中肋骨条藻与原甲藻共培养时的种间相互作用,可以由细胞间的直接接触进行,而并不需要通过介质来完成。

Algal allelopathy is a manifold ecological/physiological phenomenon which plays a crucial role in explaining microalgae distribution,community structure and the dynamics of populations within an ecosystem.In this article,interactions between Prorocentrum micans and Skeletonema costatum,causative red tide dinoflagellates,were investigated using bi-algal cultures under stable environmental conditions（temperature,light and illuminating periodicity,etc.） and sufficient nutrition supply by f/2 enrichment.The results showed that the growth of P.micans was not significantly different when cultured with S.costatum both in 1×104 cells/mL cell densities（F=0.004 48,P=0.947 960.05）,whereas the growth of S.costatum was not inhibited when cultured with P.micans in 1×104 cells/mL inoculation density（F=5.116 63,P=0.047 210.05）.Culture filtrate of P.micans induced no inhibitory effect on the growth of S.costatum,and similarly when separated by a membrane filter,S.costatum grew well when cultured in filtrate of P.micans-S.costatum,which implies that the inhibitory effect of P.micans on S.costatum in the bi-algal cultures occurred mainly by direct cell contact.The growth of P.micans and S.costatum in bi-algal cultures was simulated using a mathematical model（Lotka-Volterra） to quantify the interaction.It is indicated that P.micans outcompeted S.costatum over time.The algal interactions between P.micans and S.costatum may play an important role during the process of red tides algal species singularity and succession.