竞争条件下光照对两种淡水藻生长的影响

Effect of Light Intensity on Growth of Two Species of Algae under Competition Cultures

研究了铜绿微囊藻与斜生栅藻在单种和三种配比(10:1、1:1、1:10)共同培养条件下,不同的光照强度对其生长的影响,计算了不同培养体系中两种藻的磷吸收半饱和常数。结果表明:单独培养时,铜绿微囊藻在3000lx获得最大增长率,而斜生栅藻在5000lx时增值最快;共同培养时,两种藻的生长速率相对单独培养条件下均有不同程度的下降,两种藻之间存在着互相的竞争抑制作用;在10:1共培养条件下,栅藻对微囊藻的抑制作用超过了微囊藻对栅藻的抑制作用;在1:1和1:10共培养条件下,光强低于6600lx时,微囊藻对栅藻的抑制作用相对于栅藻对微囊藻的抑制作用更大。从光吸收半饱和常数看,微囊藻的光吸收的半饱和常数总是小于栅藻,可见微囊藻对光更具亲和性。总体上看,较低光照下,微囊藻的竞争能力强于栅藻,微囊藻竞争成为优势种具有较高的概率;而光照强度较大时,栅藻竞争成为优势种具较高的概率。

The specific growth of Microcystis aeruginosa and Scenedesmus obliquus was studied on the conditions of pure culture and three mixed culture with different light intensities and light half saturatior/ constant of each alga was calculated. Result showed that in pure Culture, Micracystis aeruginosa got the maximum specific growth rate under 3,0001x, while Scenedesmus obliquus got the maximum specific growth rate under 5,0001x. In mixed culture, the growth rate of the two algae was slower than that of pure culture, and the two algae affected each other. In the 10：1 mixture culture, the inhibition of Scenedesmus obliquus to Microcystis aeruginosa exceeded the inhibition of Microcystis aeruginosa to Scenedesmus obliquus under any light intensity. In the 1：1 and 1：10 mixture culture, the inhibition of Microcystis aeruginosa to Scenedesmus obliquus exceeds the inhibition of Scenedesmus obliquus to Microcystis aeruginosa under low light intensity. No matter which culture system it was in, light half saturation constant for Microcystis aeruginosa growth was lower than that of Scenedesmus obliquus. So Microcystis aeruginosa is more compatible with light than Scenedesmus Obliquus. Generally, Microcystis aeruginosa is easier to win in the competition in the comparative low light environment.