绿潮藻浒苔对赤潮藻中肋骨条藻化感抑制作用初探

Allelopathic effects of green tide algae Ulva prolifera on red tide algae Skeletonema costatum

研究了绿潮藻浒苔Ulva prolifera对赤潮藻中肋骨条藻Skeletonema costatum生长的化感抑制作用。分别测定了不同浒苔新鲜藻体密度、不同浒苔藻体干粉末含量、不同浒苔新鲜藻体培养过滤液体积对中肋骨条藻生长的抑制效果。结果发现,第12天共培养系统中,各浒苔新鲜藻体密度组对中肋骨条藻生长抑制率均高达100%,其中5g·L-1密度组第8天对中肋骨条藻生长的抑制已达到100%;第12天1.2g·L-1浒苔藻体干粉末含量组对中肋骨条藻生长抑制率也可达到50%左右,表明绿潮藻浒苔对中肋骨条藻生长抑制作用具有量效关系,且对中肋骨条藻生长不仅存在营养竞争抑制作用,而且还具有化感物质抑制作用。进一步采用添加浒苔新鲜藻体培养过滤液实验发现,一次性添加浒苔培养过滤液对中肋骨条藻生长抑制作用不十分明显,而半连续添加浒苔培养过滤液对中肋骨条藻生长抑制效果十分明显,其中第12天对中肋骨条藻生长抑制可达75%左右,可见浒苔藻体内的化感物质是逐步向环境中分泌的。该研究为进一步研究绿潮藻对赤潮藻化感抑制效应量效关系奠定了基础。

Allelopathic effects of green tide algaUlva prolifera on the proliferation of red tide algaeSkeletonema costatum were studied. The fresh tissue, dry powder and culture medium filtrate ofU. prolifera were used for inhibiting the proliferation ofS. costatum. Results showed that the fresh tissue ofU. prolifera could inhibit significantly the proliferation ofS. costatun. In all groups with the fresh tissue, the inhibition rate was as high as 100% after co-culturing for 12 days. As for the groups with the dry powder, the inhibition rate in the 1.2 g＆#183;L-1 group reached 50% after co-culturing for 12 days. It indicated that the inhibition of green tide algae onS. costatun proliferation presented a concentration-response relationship, and that there was not only nutrient competition inhibitory but also allelochemicals inhibition. Further studies showed that there was no significant inhibition of culture medium filtrate on the proliferation ofS. costatum in the experiment with one-time adding culture medium filtrate ofU. prolifera, while the proliferation ofS. costatum was significantly inhibited in the experiment with semi-continuously adding culture medium filtrate ofU. prolifera. The inhibition rate for semi-continuously adding culture medium filtrate ofU. prolifera was 75% after culturing for 12 days. It indicated that allelochemicals inU. prolifera was gradually released to the environment. This research laid a solid foundation for further research on concentration-response relationship betweenU. prolifera andS. costatum.