青岛沿海石莼属藻类暴发增殖的生物学调查与物种鉴定

Biological investigation and species identification of Ulva bloomed along the coast of Qingdao

中文关键词: 长石莼  藻华  形态特征  显微结构  分子鉴定

英文关键词: Ulva linza  Algae blooms  Morphological structure  Microscopic structure  Molecular identification

中文摘要:

      2009年4月下旬~6月上旬，青岛部分内湾发生漂浮绿藻暴发性生长。本文系统调查了绿潮藻华发生的区域，以青岛湾为观测点估测了生物量，其高峰期生物量可达138 t。通过对漂浮绿藻的外观形态和显微结构观察，鉴定漂浮绿藻的样本为长石莼Ulva linza，但飘浮绿藻样本与固着生长的长石莼在形态结构上有明显的不同，主要表现为叶片宽大、细胞壁加厚。为确定其物种，作者克隆了漂浮绿藻的18S-28S rDNA转录间隔区序列（Internal Transcribed Spacer，ITS）和5S rDNA串联重复间隔区序列（5S rDNA Spacer Region，5SS），采用分子系统学方法确定漂浮绿藻样品为长石莼。本文首次报道了发生在青岛内湾的长石莼藻华，同时观察到了长石莼为适应漂浮生活在形态结构上发生的适应性变化，从而为阐释其发生机制提供依据。

英文摘要:

      During late April to early June, 2009, free-floating green algae broke out in some inner bays of Qingdao. We investigated the coastal areas with green algae and found that the estimated biomass of Ulva blooms in Qingdao Bay reached 138 t at its peak time. Through morphological and microscopic examinations, the green algae samples were preliminarily indentified as Ulva linza, though they possessed wider and longer thalli and thickened cell walls compared to the immobilized Ulva linza. PCR amplification and phylogenetic analysis of the 18S-28S rDNA internal transcribed spacer (ITS) and 5S rDNA spacer region (5SS) of the free-floating samples confirmed that the free-floating algae was Ulva linza. Morphological changes could help free-floating Ulva linza adapt to the new drifting life. This is the first time that the Ulva linza blooms in inner bays of Qingdao was reported.