川蔓藻对两种常见浮游藻类的化感作用

Allelopathic effect of Ruppia maritima on Chlorella vulgaris and Microcystis aeruginosa

选取沉水植物川蔓藻与浮游藻类普通小球藻、铜绿微囊藻为研究对象,测定在川蔓藻共培养胁迫下2种藻单独存在和按1:1(V:V)混合情况下的光密度、叶绿素a、最大光化学量子产量、相对电子传递速率、可溶性糖、丙二醛以及超氧化物歧化酶活性的变化.结果表明:在川蔓藻存在的条件下,普通小球藻、铜绿微囊藻和二者混合藻的生长被快速强烈抑制,抑制率在第6d时达到最大值,分别为80.95%、94.18%和94.01%.3个处理组的光密度值、叶绿素a、可溶性糖及最大光化学量子产量等指标均低于对照组,且随时间呈明显的下降趋势,说明其光合能力逐渐减弱.而丙二醛和超氧化物歧化酶指标在0～6d却高于对照组,表明可能发生了浮游藻类膜质过氧化过程.

One submerged macrophyte (Ruppia maritima) and two algae (Chlorella vulgaris and Microcystis aeruginosa) were selected to test the allelopathic effect of submerged macrophyte on algae. The parameters including optical density, chlorophyll a, maximum photochemical quantum yield, relative electron transport rate, soluble sugar, malondialdehyde, and superoxide dismutase activity were measured for three co-culture treatments of Ruppia maritima + Chlorella vulgaris, Ruppia maritima + Microcystis aeruginosa, and Ruppia maritima + mixture of Chlorella vulgaris and Microcystis aeruginosa (V:V=1:1). The growth of Chlorella vulgaris, Microcystis aeruginosa and mixed algae were rapidly and greatly inhibited with the presence of Ruppia maritima. The inhibition rates in the three treatments reached the maximums on the 6th day, which were 80.95%, 94.18% and 94.01%, respectively. The values of optical density, chlorophyll a, soluble sugar and maximum photochemical quantum yield for the three treatments were lower than those for the corresponding controls, and showed a significantly downward trend with time, indicating that the photosynthetic capacity of the treatments became weakening gradually. However, the values of malondialdehyde and superoxide dismutase of the treatments were higher than those of the corresponding controls for the first six days, indicating the possible occurrence of the membrane peroxidation of the algae.