海州湾条斑紫菜养殖对浮游藻类群落结构及遗传多样性的影响

为了研究条斑紫菜(Porphyra yezoensis)养殖对江苏海州湾浮游藻类群落结构及遗传多样性的影响,于江苏省海州湾条斑紫菜养殖及非养殖海区各设置4个采样位点,采集表层海水,提取海水中浮游藻类的总DNA,PCR扩增浮游藻类核酮糖1,5-二磷酸羧化/氧化酶大亚基(rbc L)基因片段,构建了养殖及非养殖海区rbc L片段质粒文库。在文库中随机选择50个阳性克隆并测序。经比对分析,在条斑紫菜非养殖区发现8种海洋微藻,隐鞭藻占总克隆数22%,海链藻和骨条藻分别占6%和2%;养殖海区发现10种微藻,其中异丝藻占总克隆数22%,优势度明显,仅3种微藻为二海区共有(骨条藻、隐鞭藻及小球藻),表明紫菜养殖及非养殖区浮游藻类群落组成差异显著。条斑紫菜非养殖区及养殖区的浮游藻类香农指数均值分别为3.273和3.654,均匀度指数均值分别为1.090和1.040,显示养殖区浮游藻类遗传多样性较丰富,而群落的成熟度与稳定性非养殖区高。研究证实,表层海水浮游藻类群落结构及组成是动态的,条斑紫菜的养殖行为形成浮游藻类群落结构及遗传多样性较大差异性。

Effect of Porphyra yezoensis farming on the structure and genetic diversity of phytoplankton community in Haizhou Bay

In order to investigate the effect of Porphyra yezoensis farming on the structure and genetic diversity of phytoplankton community in Haizhou Bay in Jiangsu, four sampling sites were set in each P. yezoensis breeding and non-breeding sea in Haizhou Bay in Jiangsu Province in December 2012. The surface water was collected and the total DNA of seawater was extracted. The planktonic algae ribulose 1, 5-bisphosphate carboxylase/oxide large subunit (rbcL) gene was amplified using PCR, which was used to construct a plasmid library of breeding and non-breeding sea rbcL fragment. 50 positive clones of the library were selected randomly and sequenced. After a comparative analysis, eight species of marine microalgae were found in non-breeding areas, among which, Cryptomonas made up 22% of the total number of clones, Thalassiosira and Skeletonema were smaller proportion, accounting for 6% and 2%, respectively. 10 kinds of marine microalgae were found in breeding sea, among which Heterosigma has the obvious superiority, accounting for 22% of the total number of clones. Only three kinds of microalgae (Skeletonema, Cryptomonas and Chlorella) were found in both breeding areas and non-breeding areas, suggesting that phytoplankton community composition was significantly different between breeding areas and non-breeding areas. The average Shannon index of sea phytoplankton in P. yezoensis non-breeding and breeding areas was 3.273 and 3.654, respectively. The average evenness index was 1.090 and 1.040, respectively, suggesting breeding areas were rich in phytoplankton with genetic diversity, while the maturity and stability of the community were high in non-breeding areas. Our study confirmed that the structure and composition of phytoplankton community is dynamic, and P. yezoensis farming changed community structure and genetic diversity of phytoplankton.