不同营养条件对东海原甲藻和中肋骨条藻竞争参数的影响

以东海原甲藻和中肋骨条藻为研究对象,采用室内单种培养和混合培养,设置不同的氮、磷营养条件,研究了不同营养条件对两种微藻的生长状况和种间竞争参数的影响.结果表明:随着氮、磷浓度的增加,两种藻的最大生物量均呈增加趋势,混合培养中两种微藻的比生长率低于单独培养.在混合培养中,生长前期中肋骨条藻是优势种,随着培养时间的延长,东海原甲藻成为优势种,且优势种发生变化的时间与营养条件有关.混合培养中,东海原甲藻拐点出现时间在0.5 ～4.9 d,中肋骨条藻为0～2.6d,东海原甲藻拐点出现时间晚于中肋骨条藻.在各营养条件下,东海原甲藻对中肋骨条藻的竞争抑制参数β均高于中肋骨条藻对东海原甲藻的竞争抑制参数α,当N为128μmol·L-1、P为32 μmol·L-1时,东海原甲藻的竞争能力是中肋骨条藻的3.8倍,两者差异最为明显.

Effects of nutritional condition on the competitive parameters of Prorocentrum donghaiense and Skeletonema costatum

By the methods of pure culture and mixed culture in laboratory, this paper studied the effects of different substrate nitrogen and phosphorus concentrations on the population growth and interspecific competitive parameters of two kinds of microalgae, Skeletonema costatum and Prorocentrum donghaiens. With the increasing concentrations of substrate nitrogen and phosphorus, the maximum biomass of the two kinds of microalgae increased, and their specific growth rate was higher in pure culture than in mixed culture. In mixed culture, S. costatum was dominant at the beginning, while P. donghaiense became dominant later. The time period when this change happened was related to the nutritional conditions, and the inflection point for S. costatum and P. donghaiense was about 0-2.6 and 0.5-4.9 d, respectively. Under the test nutritional conditions, the competitive parameter of P. donghaiense to S. costatum (beta) was higher than that of S. costatum to P. donghaiense (alpha). When the substrate nitrogen and phosphorous concentrations were 128 micromol N x L(-1) and 32 micromol P x L(-1), the competitive capability of P. donghaiense was 3.8 times of that of S. costatum, presenting the most obvious difference.