共培养条件下强壮前沟藻与中肋骨条藻的相互作用

摘要

半连续条件下研究了强壮前沟藻与中肋骨条藻不同接种密度下种间的相互作用,按照以下条件:(1)1×10<'4>个/cm<'3>强壮前沟藻与1×10<'4>个/cm<'3>中肋骨条藻;(2)1×10<'4>个/cm<'3>强壮前沟藻与5×10<'4>个/cm<'3>中肋骨条藻;(3)1×10<'4>个/cm<'3>强壮前沟藻与10×10<'4>个/cm<'3>中肋骨条藻接种进行共培养实验;在五种培养滤液中培养中肋骨条藻,起始密度为1×10<'4>个/cm<'3>利用双藻竞争模型分析两者的竞争抑制参数,结果表明:半连续共培养条件下,强壮前沟藻对三种接种密度的中肋骨条藻都产生强烈的生长抑制作用(P<0.05),三种接种密度比例下强壮前沟藻对中肋骨条藻的抑制能力分别是中肋骨条藻对强壮前沟藻抑制能力的8.2,3.4和14.2倍;不同接种密度中肋骨条藻对强壮前沟藻的生长抑制作用并没有显著的差异(P>0.05);中肋骨条藻在五种去藻滤液中生长都受到显著抑制(P<0.05),强壮前沟藻中肋骨条藻与强壮前沟藻共培养实验结果表明,对中肋骨条藻的生长具有抑制作用,这种抑制作用是可以通过分泌胞外产物来实现,而与细胞的直接接触没有必然联系.%In order to investigate the growth interactions between each microalgae, two microalgae Amphidinium carterae Hulburt and Skeletonerna costatum (Greville) Cleve were studied with different densities using semi-continuous cultures in controlled laboratory conditions (temperature, light and illuminating periodicity, etc.) and sufficient nutrition supply every day.When 1 × 104 cell/cms A.carterae and 1 × 104cells/cms S.costatum were inoculated into the same medium, growth of A.carterae was slightly suppressed, while S.costaturn was notably suppressed.Other inoculum resulted in reduced S.costatum maximum cell densities.These results were consistent with those of simultaneous assays using cell-free filtrates of mono-algal and semi-continuous cultures.That is, exposure to cell-free filtrates of A.carterae or A.carterae s-S.costaturn had a inhibitory effect on S.costatum.A mathematical model was used to simulategrowth and interactions of A.carterae and S.costatum in semi-continuous cultures, which indicated thatA.carterae outcompeted S.costatum over time.And the inhibition exerted by A.carterae on S.costatumwas about 8.2, 3.4 and 14.2 times stronger than the inhibition exerted by S.costatum on A.carteraewhen they were set at A.carterae and 1 × 104 cells/cm3 S.costatum, A.carterae and 5 × 104 cells/cms S.costatum and A.carterae and 10 × 104 cells/cm3 S.costatum, respectively.These results successfully demonstrate that allelopathy is involved in the growth interactions between A.carterae and S.costatum, and extraeellular metabolites have been suggested to be one factor contributing to the formation and/or maintenance of dinoflagellate blooms.Cell-free filtrate cultures is one of the basic approaches on allelopathy research which noted that cell-to-cell contact is not necessary for inhibitory effects between algae.