Complete nuclear ribosomal DNA sequence amplification and molecular analyses of <Emphasis Type="Italic">Bangia</Emphasis> (Bangiales,Rhodophyta) from China

Filamentous Bangia, which are distributed extensively throughout the world, have simple and similar morphological characteristics. Scientists can classify these organisms using molecular markers in combination with morphology. We successfully sequenced the complete nuclear ribosomal DNA, approximately 13 kb in length, from a marine Bangia population. We further analyzed the small subunit ribosomal DNA gene (nrSSU) and the internal transcribed spacer (ITS) sequence regions along with nine other marine, and two freshwater Bangia samples from China. Pairwise distances of the nrSSU and 5.8S ribosomal DNA gene sequences show the marine samples grouping together with low divergences (00.003; 0–0.006, respectively) from each other, but high divergences (0.123–0.126; 0.198, respectively) from freshwater samples. An exception is the marine sample collected from Weihai, which shows high divergence from both other marine samples (0.063–0.065; 0.129, respectively) and the freshwater samples (0.097; 0.120, respectively). A maximum likelihood phylogenetic tree based on a combined SSU-ITS dataset with maximum likelihood method shows the samples divided into three clades, with the two marine sample clades containing Bangia spp. from North America, Europe, Asia, and Australia; and one freshwater clade, containing Bangia atropurpurea from North America and China.     

法紫菜生物多样性及其栽培生物学基础

综述了重要经济红藻法紫菜属物种多样性及其地理分布,修订了法紫菜属中文名称,回顾了紫菜生活史研究的历程,基本概括了法紫菜栽培生物学基础研究成果。根据文献报道及最新研究成果,认为紫菜属和法紫菜属共有138个物种,集中分布在北半球的温带、亚热带海域,其中我国是物种多样性较高的国家之一,其物种及变种数达到25个。法紫菜生活史的阐明对紫菜栽培产业的发展具有奠基性的作用,其中我国藻类学家曾呈奎和张德瑞在法紫菜生活史研究中作出了重要的贡献,提出了壳孢子的概念,被广泛接受并沿用至今。壳孢子采苗和丝状体培养技术是发展紫菜栽培业的重要基础,丝状体生长发育及壳孢子形成的分子机制将是未来法紫菜生物学研究的重点和难点。尽管根据已发表的相关文献大致梳理了法紫菜相关生物学基础研究的成果,但限于篇幅对栽培生产中相关技术的优化、完善与推广以及新品种培育等均未作介绍。     

坛紫菜叶状体营养细胞与生殖细胞叶绿素荧光特性比较

利用叶绿素荧光技术对坛紫菜(Porphyra haitanensis)叶状体营养细胞和生殖细胞的光能利用特性进行了比较。结果表明:坛紫菜叶状体营养细胞和雌性生殖细胞的实际量子效率(ΔF/Fm′)差异不明显,但显著高于雄性生殖细胞;快速光曲线测定表明雌、雄藻体营养细胞的最大相对电子传递速率(rETRmax)相近,但显著高于雄性生殖细胞;不同生殖细胞半饱和光强(Ik)无显著差异;在生长光强下,营养细胞和雌性生殖细胞rETR、光化学猝灭(qP)和非光化学猝灭(NPQ)差异不明显,而雄性生殖细胞rETR、qP等荧光参数均显著低于营养细胞和雌性生殖细胞。本文表明坛紫菜叶状体营养细胞和雌性生殖细胞具有较高的光能利用能力,能够将吸收的光能多数用于电子传递,而雄性生殖细胞对光能的利用能力较低。     

基于叶绿素荧光技术的紫菜光适应特征研究

通过水样调制式叶绿素荧光仪,对坛紫菜、条斑紫菜叶状体和丝状体在不同光照条件下叶绿素荧光特性进行研究.结果表明:紫菜叶状体和丝状体实际量子效率在光照处理后逐步下降,且随着处理光强的上升,实际量子效率的下降速率更为明显.快速光曲线初始斜率(α)结果与实际量子效率相似,表明光照时间的延长以及光照强度的升高均引起样品实际光能利...