菹草对小球藻和卵囊藻的形态化感效应研究

研究生态修复过程中沉水植物对藻类的影响,为水生态修复提供理论依据。选用常见沉水植物菹草(Potamogeton crispus)研磨液为培养液,对常见绿藻普通小球藻(Chlorella vulgaris)和卵囊藻(Oocystis sp.)开展室内模拟试验培养,通过绿藻生长和形态特征的变化,了解新鲜菹草是否对普通小球藻和卵囊藻存在一定的化感效应。研究结果表明,菹草对普通小球藻和卵囊藻的生长均未呈现显著抑制效应;普通小球藻对菹草具有形态响应,一次性添加的菹草研磨液在试验初期显著促进普通小球藻群体的形成,随着时间的推移,群体普通小球藻逐渐裂开转化为小群体或者是单细胞;试验结果还表明,菹草对卵囊藻形态无显著影响。

Allelopathic Effect of the Macrophyte Potamogeton Crispus on Colony Formation of Chlorella Vulgaris and Oocystis sp.

In aquatic ecosystems, many planktonic algae exhibit phenotypic plasticity in response to changes in the external environment, and morphological change during colony formation is an expression of phenotypic plasticity. Previous research has shown that submerged aquatic plants can induce morphological change in planktonic algae. This study explored the effect of submerged aquatic plants on algal morphology, and the response of green algae to submerged macrophytes. Two species of green algae, Chlorella vulgaris and Oocystis sp., were cultured in solutions containing an extract obtained from grinding the macrophyte Potamogeton crispus. A 10 day experiment was set with a control group and a group treated with P. crispus extract, and each trial was run in triplicate. During the test, the growth and changes in morphology of the two algae were measured each day. The P. crispus extract did not significantly inhibit the growth of C. vulgaris and Oocystis sp., but did induce colony formation of C. vulgaris during early stages of the experiment. Colony formation and average cell number per colony differed significantly from the control group. The number and scale of C. vulgaris colonies peaked on day 3, after which the colony gradually fragmented into smaller groups and single cells. However, P. crispus extract did not induce morphological changes in Oocystis sp.. These results contribute to the theoretical base for using submerged macrophytes in the restoration of aquatic ecosystems.