浒苔与球等鞭金藻相互抑制的实验验证

Experimental validation on inhibitory effects between Ulva prolifera and Isochrysis galbana under controlled laboratory conditions

摘要:

研究了实验室条件下漂浮绿潮海藻浒苔（Ulva prolifera ）与微藻球等鞭金藻（Isochrysis galbana）之间的相互抑制作用，并对作用机制进行了初步探讨。结果表明，在浒苔和球等鞭金藻初接种量分别为1 gFW/L和1×10⁴ cells/mL的共培养系统中，实验初始阶段（前3 d）NO₃^-、PO₄^3-浓度显著高于浒苔和球等鞭金藻各单培养组，说明共培养系统中浒苔和球等鞭金藻彼此之间产生了显著抑制作用，其中浒苔对球等鞭金藻抑制率为96.62%，球等鞭金藻对浒苔的抑制率为19.67%，从而导致对NO₃^-、PO₄^3-吸收速率的降低；从第4天到实验结束，共培养体系中NO₃^-、PO₄^3-浓度逐渐升高，镜检也显示浒苔和球等鞭金藻细胞发生了断裂、肿胀和死亡现象，而单培养组中NO₃^-、PO₄^3-浓度持续下降，说明共培养系统中由于浒苔和球等鞭金藻的死亡而向培养液中释放了营养盐。本研究表明在营养盐浓度和浒苔生物量相对较低的情况下，浒苔和球等鞭金藻彼此之间存在化感作用。

Abstract:

In this paper, the experimental validation on inhibitory effects between Ulva prolifera , a popular specie of green tides in the Yellow Sea, and Isochrysis galbana under controlled laboratory conditions, and the possible mechanism was studied. In the coculture system with 〖WTBX〗Ulva prolifera〖WTBZ〗 at 1 gFW·L ^-1 and Isochrysis galbana at 1×10 ⁴ cells/ml, the concentration of NO₃^--N and PO₄^3--P were significantly higher in the cocultured medium than that in the monocultured medium of U.prolifera and I.galbana for initial 3 days. It indicated there was inhibitory effect between Ulva prolifera and Isochrysis galbana, and the inhibitory rate for U.prolifera to I.Galbana was 96.62%, while the inhibitory rate for I.Galbana to U.prolifera was 19.67%. It resulted in decrease of uptake rate of U.prolifera and I.Galbana for nutrients. From the fourth day to the end, the concentratons of NO₃^--N and PO₄^3--P were gradually increased, and the cell breakdown, swollen and death of U.prolifera and I.Galban were observed under microscope. The concentration of NO₃^--N and PO₄^3--P in the monocultured medium was constantly decreased. It indicated that U.prolifera and I.galbana released nutrients into the seawater. It demonstrated that there was the allelopathic effect between U.prolifera and I.galbana when the nutrients in seawater and the biomass of U.Prolifera were relatively low.