Characterization of a new lectin involved in the protoplast regeneration of Bryopsis hypnoides

A group of coenocytic marine algae differs from higher plants, whose totipotency depends on an intact cell (or protoplast). Instead, this alga is able to aggregate its extruded protoplasm in sea water and generate new mature individuals. It is thought that lectins play a key role in the aggregation process. We purified a lectin associated with the aggregation of cell organelles in Bryopsis hypnoides. The lectin was ca. 27 kDa with a pI between pH 5 and pH 6. The absence of carbohydrate suggested that the lectin was not a glycoprotein. The hemagglutinating activity (HA) of the lectin was not dependent on the. presence of divalent cations and was inhibited by N-Acetylgalactosamine, N-Acetylglucosamine, and the glycoprotein bovine submaxillary mucin. The lectin preferentially agglutinated Gram-negative bacterium. The HA of this lectin was stable between pH 4 to pH 10. Cell organelles outside the cytoplasm were agglutinated by the addition of lectin solution (0.5 mg ml(-1)). Our results suggest that the regeneration of B. hypnoides is mediated by this lectin. We also demonstrated that the formation of cell organelle aggregates was inhibited by nigericin in natural seawater (pH 8.0). Given that nigericin dissipates proton gradients across the membrane, we hypothesize that the aggregation of cell organelles was proton-gradient dependent.

Solving the coastal eutrophication problem by large scale seaweed cultivation

Eutrophication is becoming a serious problem in coastal waters in many parts of the world. It induces the phytoplankton blooms including 'Red Tides', followed by heavy economic losses to extensive aquaculture area. Some cultivated seaweeds have very high productivity and could absorb large quantities of N, P, CO2, produce large amount of O-2 and have excellent effect on decreasing eutrophication. The author believes that seaweed cultivation in large scale should be a good solution to the eutrophication problem in coastal waters. To put this idea into practice, four conditions should be fulfilled: (a) Large-scale cultivation could be conducted within the region experiencing eutrophication. (b) Fundamental scientific and technological problems for cultivation should have been solved. (c) Cultivation should not impose any harmful ecological effects. (d) Cultivation must be economically feasible and profitable. In northern China, large-scale cultivation of Laminaria japonica Aresch. has been encouraged for years to balance the negative effects from scallop cultivation. Preliminary research in recent years has shown that Gracilaria lemaneiformis (Bory) Daws. and Porphyra haitanensis Chang et Zheng are the two best candidates for this purpose along the Chinese southeast to southern coast from Fujian to Guangdong, Guangxi and Hong Kong. Gracilaria tenuistipitata var. liui Chang et Xia is promising for use in pond culture condition with shrimps and fish.

Molecular biotechnology of marine algae in China

Molecular biotechnology of marine algae is referred to as the biotechnology on the identification, modification, production and utilization of marine algal molecules. It involves not only the manipulation of macromolecules such as DNA, RNA and proteins, but also deals with low molecular weight compounds such as secondary metabolites. In the last decade, molecular systematic researches to investigate the relationship and to examine the evolutionary divergence among Chinese marine algae have been carried out by Chinese scientists. For example, RAPD has been widely used in several laboratories to elucidate genetic variations of the reds, such as Porphyra, Gracilaria, Grateloupia and the greens such as Ulva and Enteromorpha. Some important data have been obtained. The study on molecular genetic markers for strain improvement is now in progress. In 1990s, genetic engineering of economic seaweeds such as Laminaria, Undaria, Porphyra, Gracilaria and Grateloupia has been studied in China. For Laminaria japonica, the successfully cultivated kelp in China, a model transformation system has been set up based on the application of plant genetic techniques and knowledge of the algal life history. Progress has been made recently in incorporating a vaccine gene into kelp genome. Evidence has been provided showing the expression of gene products as detectable vaccines. In the present paper, the progress of molecular biotechnological studies of marine algae in China, especially researches on elucidating and manipulating nucleic acids of marine algae, are reviewed.

The past, present and future of phycology in China

Algae have been part of Chinese life for thousands of years. They are widely used as food and have been cited in Chinese literature as early as 2500 years ago. However, formal taxonomic studies on Chinese algae were initiated by foreign scientists only about 200 years ago, and by Chinese phycologists only about 90 years ago. This paper summarizes the history of modern phycological studies on Chinese algae and provides an overview of the achievements of phycological studies by Chinese scientists, especially on algal taxonomy, morphology, genetics, ecology and environmental research, physiology, biotechnology, algal culture, applied phycology and space phycology, in the last century. Recent development in phycological research focuses on algal floristic and molecular systematics, algal molecular biotechnology, applied phycology including micro and macroalgal cultivation and algal product development, and the roles of algae in environmental pollution control. These areas will also be the main focuses of Chinese phycological research in the foreseeable future.

Mass culture of Undaria gametophyte clones and their use in sporeling culture

Undaria pinnatifida (Harv.) Sur. is one of the three main seaweed species under commercial cultivation in China. In the mid-1990s the annual production was about 20000 tons dry. The supply of healthy sporelings is key to the success of commercial cultivation of Undaria. Previous studies demonstrated that instead of the zoospore collection method, sporelings can be cultured through the use of gametophyte clones. This paper reports the experimental results on mass culture of clones and sporeling raising in commercial scale. Light had an obvious effect on growth of gametophyte clones. Under an irradiance of 80 mumol m(-2) s(-1) and favorable temperature of 22-25degreesC, mean daily growth rate may reach as high as 37%. Several celled gametophyte fragments were sprayed onto the palm rope frame. Gametogenesis occurred after 4-6 days. Juvenile sporeling growth experiments showed that nitrate and phosphate concentrations of 2.9 10(-4) mol 1(-1) and 1.7 10(-5) mol 1(-1) were sufficient to enable the sporelings to maintain a high daily growth rate. Sporelings can reach a length of 1 cm in a month. Since 1997, extension of the clone technique has been carried out in Shandong Province. Large-scale production of sporelings for commercial cultivation of 14 and 31 hectares in 1997 and 1998 had been conducted successfully.

PYRITE GENESIS DURING EARLY DIAGENESIS IN YELLOW SEA AND EAST-CHINA-SEA

The content and isotopic compositions of different sulphur species in pore-water and solid phases have been examined on five sediment cores taken from muddy sediment region in the Yellow Sea and the East China Sea. Relationships among these data have been investigated with the combination of morphology of mineral pyrite and organic matter so as to role out the diagenetic behaviour of sulphur species at the early stage of diagenesis in modern marine sediment and the origin of pyrite formation.

南海文昌海域内波特征研究

2005年中科院海洋所对琼东文昌海域进行了精细内波观测。本文对此次观测所获得的资料进行分析，研究了观测海域内孤立波、内潮、内波波致流和内波传播方向的统计特征，得到观测海域内波的基本特征。首先，观测海域内孤立波频繁发生。在149天的观测当中，一共出现140个孤立波列，出现频率达到了0.94次/天。出现频率最高的振幅是32米，最常见的内孤立波持续时间时20分钟。80%的内孤立波都在以下范围之内：持续时间从13分钟到32分钟，振幅从16米到46米。在这一区间范围之类，内孤立波的持续时间和振幅并没有明显的函数关系，表现出随机分布的特征。同时内孤立波的振幅有着明显的季节变化特征。从4月中旬到6月中旬内孤立波频繁出现且振幅较大，振幅超过35米的内孤立波相当常见；而6月中旬到9月中旬，内孤立波的发生频率明显下降，振幅也偏低，振幅超过35米的内孤立波属于少数情况。其次，观测地的内潮以日频率的振动为主，间隔有半日频率的内潮出现，与当地天文潮情况相似。其振幅小于内孤立波的振幅，在每个观测日都能观测到。内潮的振幅有着明显的季节变化，7月是内潮振幅最小的一个月。再次，观测地内波波致流的大小和剪切层位置有着明显的季节变化。在4月和5月内波波致流流速较大而且靠近海底。而在6月以后，内波波致流较弱，并且剪切层也更为靠近海面。最后，观测地内波可能在局地生成，由于主要呈现全日频率可以排除在吕宋海峡生成的可能。同时传播方向同样随季节变化。4月和5月观测到的内波传播方向主要与等深线线平行，极少被卫星遥感图片观测到。6月、7月、8月和9月传播方向与等深线垂直。

黄东海胶质浮游动物水母类研究

近年来，胶质类浮游动物尤其是水母类在近岸高生产力的海洋生态系统中的作用越来越受到全球科学家们的关注。这种关注很大程度上是由于近年来很多海域或海湾出现水母类大量繁殖的现象而引起的，这种现象与过度捕捞、气候变化、富营养化以及生物入侵等因素有着内在的联系，给人们带来经济，社会和生态等各方面的损失。这种损失包括：当水母大量出现时，由于它们与鱼类存在食物和捕食竞争，使渔业资源和渔业生产锐减；由于它们会堵塞和撕破渔业生产网，干扰了人们的渔业生产活动；另外水母增多增加了海滨游泳爱好者被蛰伤甚至死亡事件发生的频率，对旅游者们的娱乐行为造成不便。到目前为止全球范围内报道了许多水母大量繁殖并对经济社会或海洋生态系统造成负面影响的事件。在北海水母数量爆发的频率与气候相关的事实表明了该海域将要面临一个更多的胶质类浮游动物的未来。所有这些都表明海洋中水母的生态学问题仍旧是全球的一个研究热点。到目前为止，在世界上许多海湾和海区有关水母生态学问题的研究上，均已取得方方面面有意义的进展。但在我国，由于对水母功能群的研究缺乏足够的重视，对于大型水母来讲它们被认为是渔业生产的副产品或者‘垃圾’，在渔业拖网捕获后把它们直接扔入海中并不去研究；对于小型水母来讲，因为它们为非饵料生物，并且有易碎，粘糊糊等难操作的特点，对浮游生物网同步采集到的水母的研究力度远不如对其他浮游动物类群的研究力度，因此我国对水母功能群生态学的研究基础相当薄弱。 本论文基于以上背景对黄东海大型和小型水母类的生物地理分布格局进行了研究，对其生物量或丰度等生态学指标进行了定量研究。（1）利用浮游生物网样品对黄海小型水母类的种类组成及其丰度的时空变化进行了研究，表明黄海测区内小型水母整体丰度很低，且主要分布在50 m等深线以浅海域，各水母类群以及优势种类的季节更替非常明显。比较不同海区的小型水母的丰度水平及其占浮游动物丰度的比例，发现黄海的小型水母丰度水平最低，为0.8（0.04–1.3）ind. m-3，只占浮游动物丰度的 < 0.5 %，表明小型水母在黄海海域并非占优势的功能群。（2）在中国黄东海采集的沙海蜇和在日本采集的越前水母的COI基因序列差异（0.2%）处于种内水平，从分子水平上证明两者为同一个种类，基于形态学和分子生物学的证据，我国大型水母沙海蜇的分类地位可初步订正为：Nemopilema nomurai Kishinouye, 1922（Scyphozoa：Rhizostomeae：Rhizostomatidae）。（3）利用渔业底层拖网的方法对黄东海大型水母的种类组成，总生物量及各优势种类生物量的时空分布进行了半定量研究。结果共鉴定到11个种（类），其中沙海蜇（Nemopilema nomurai），洋须水母（Ulmaridae genus sp.）以及多管水母（Aequorea spp.）为黄海的优势种（类），沙海蜇（只在东海北部）和霞水母（Cyanea spp.）为东海的优势种（类）；这四个种（类）的湿重随着伞径的增大成冪增长的方式。大型水母平均总生物量的季节变化模式为：3月份水母总生物量最低，为4.6 ± 9.4 kg km–2，春夏季随着海水表层温度的升高，大型水母的生物量逐渐增加，9月初水母的总生物量达到最高值，为22891 ± 25888 kg km–2，随后随着海水的温度下降，生物量也逐渐下降。洋须水母的生物量在10月份达到最高值（2780 ind. km–2，1807 kg km–2），主要在黄海中部出现。多管水母在5月份丰度最高，为8262 kg km–2，且主要分布在30N以北海域。 聚焦大量爆发的水母种（类）沙海蜇和霞水母，基于实测的拖网资料，提供了该种可见的浮游阶段1周年的地理发生和生物量数据；结果表明，这两个种（类）表现了不同的季节出现和生物量格局：首先是黄海出现的沙海蜇（5–12月在黄海出现），5月份少量幼水母体在黄东海的交界处出现，6月它们的分布范围在南黄海扩大，到8月末及9月初沙海蜇几乎遍布黄海，其生物量和丰度以压倒其他大型水母类的优势形成“bloom”（生物量占所有大型水母的96.7%，丰度占93%，在南黄海平均生物量20446 kg km-2，平均占渔获物生物量的86.1 %），10月份至12月，沙海蜇的生物量逐渐减少甚至为零，其分布区域也向北回缩。其次为东海出现的霞水母（5月–10月）：霞水母在5月初达到生物量的高值（平均生物量为380 kg km-2），其伞径随纬度的升高而变小，8月至10月其生物量骤然下降。这两个种类的生物量高值分布在温度或潮汐锋区。结合水文条件及沙海蜇和霞水母关键的生活史策略推测了黄东海该种浮游阶段的生活史模型。 最后，通过对黄海8、9月份沙海蜇生物量的最高峰或暴发时期的呼吸率，摄食率进行估算，获得其每天对浮游动物现存量及生产力的潜在摄食压力，结果表明2006年9月在对沙海蜇最大捕获率的情况下，沙海蜇的摄食率为8.37（0.12–37.83）mg C m-2d-1，假设都以浮游动物为食，这时每天对浮游动物现存量及生产力的摄食压力分别为11.2%（0.17–50.6%），134.1%（1.98–605.7%）。因此在沙海蜇暴发期间对浮游动物的潜在的消耗非常大，甚至为毁灭性的。

Environmental and health effects associated with Harmful Algal Bloom and marine algal toxins in China

The frequency and scale of Harmful Algal Bloom (HAB) and marine algal toxin incidents have been increasing and spreading in the past two decades, causing damages to the marine environment and threatening human life through contaminated seafood. To better understand the effect of HAB and marine algal toxins on marine environment and human health in China, this paper overviews HAB occurrence and marine algal toxin incidents, as well as their environmental and health effects in this country. HAB has been increasing rapidly along the Chinese coast since the 1970s, and at least 512 documented HAB events have occurred from 1952 to 2002 in the Chinese mainland. It has been found that PSP and DSP toxins are distributed widely along both the northern and southern Chinese coasts. The HAB and marine algal toxin events during the 1990s in China were summarized, showing that the HAB and algal toxins resulted in great damages to local fisheries, marine culture, quality of marine environment, and human health. Therefore, to protect the coastal environment and human health, attention to HAB and marine algal toxins is urgently needed from the environmental and epidemiological view.

Four new species of the Genera Eudesme and Sphaerotrichia (Chordariaceae, Heterokontophyta) from the Chinese Coast

Four new species, Eudesme huanghaiensis Ding et Lu, E. qingdaoensis Ding et Lu, E. shandongensis Ding et Lu and Sphaerotrichia huanghaiensis Ding et Lu, from the western Yellow Sea coast of China are described. Eudesme huanghaiensis is mainly characterized by its spherical or sub-spherical sub-cortical cells, its rhizoidal filaments developing from the basal cells of sub-cortex and its broad sub-cortical and medullary layers. E. qingdaoensis is mainly characterized by its long medullary cells, generally hollow center of the medulla, short sub-cortex with only 3-4 cylindrical cells and long, slender and clavate terminal cells of the rhizoidal filaments. E. shandongensis is mainly characterized by its hollow frond, thick cell walls of both medulla and inner sub-cortical layers and the spherical terminal cells of the rhizoid filaments. Sphaerotrichia huanghaiensis is mainly characterized by its cylindrical, sparsely branched frond with acute angle, and its thick 5-6 layered sub-cortex with long assimilating filaments of 6-10 cells.

Studies on four new species of the malacocarpic Sargassum (Sargassaceae, Heterokontophyta) in China

In this paper, four new species of malacocarpic Sargassum are described: S. fuliginosoides Tseng et Lu sp. nov. is characterized by its discoid holdfast, the presence of the bulbs on the basal parts of the primary branches and very thick, lanceolate leaves. S. gemmiphorum Tseng et Lu sp. nov. is characterized by its conical holdfast, usually branched axis and very long, narrow, thin, denticulate leaves. S. shandongense Tseng, Zhang et Lu sp. nov. is characterized by its discoid holdfast, flattened primary branches, its leaves mostly entire or wavy at the margins and its racemose to paniculate receptacles. S. qingdaoense Tseng et Lu sp. nov. is characterized by the presence of the glandular dots on the ultimate branches and elongated lanceolate, acute, mostly wavy leaves.

Studies on Chinese species of Gelidiella and Pterocladiella (Gelidiales, Rhodophyta)

A detailed study of materials from our herbarium shows the presence of two species of Gelidiella and three species of Pterocladiella, including two new records and a new species. Previously recorded species include G. acerosa and P. capillacea. G. bornetii and P. caerulescens are new records for China and P. yinggehaiensis is believed to be a new species. This new species is characterized by its small thalli, 1.5-2 cm high, that are more densely branched on the middle to upper parts for one half their lengths. These characteristics are so distinctive that they can be used to separate this species readily from other species now reported in this genus.

高效液相色谱-质谱分离鉴定荧光试剂标记的脂肪酸

以2-(2-(10-蒽基)-萘[2,3-d]咪唑)-乙基-对甲苯磺酸酯(ANITS)作为柱前衍生化试剂,在Eclipse XDB-C8色谱柱上,梯度洗脱实现了20种游离脂肪酸(FFA)衍生物的完全基线分离.90℃下在DMF溶剂中以K2CO3作催化剂,选取衍生试剂摩尔数为脂肪酸的7倍,衍生反应40 min可获得稳定的荧光产物.激发和发射波长分别为250 nm和512 nm.采用大气压化学电离源(APCI)正离子模式,实现了油菜蜂花粉中游离脂肪酸的质谱鉴定.所有脂肪酸的线性相关系数均大于0.9999, 检出限为24.76～98.79 fmol.

基于叶绿体DNA trnT-trnF序列研究祁连圆柏的谱系地理学

由于青藏高原的地貌效应,第四纪冰期气候的反复变化应对现今该地区生物的地理分布及其居群遗传结构产生重大影响.本文对这一地区特有分布物种祁连圆柏Juniperus przewalskii Kom.整个分布区内20居群392个个体的trnT-trnF序列变化进行了研究;共发现3种单倍型(haplotype),构成两种地理区域:高原台面上的居群主要固定HapA,而HapA、HapB和HapC在高原边缘居群均有分布.所有居群总的遗传多样性HT=0.511,GST=0.847.在低海拔的高原边缘,Hap A、Hap B和Hap C高频率固定在不同的居群中,表明可能存在多个不同的避难所,居群反复缩小和扩张的瓶颈效应造成了遗传多样性的丢失.而边缘的一个居群含有两种相似单倍型频率则可能是冰期后迁移融合而成或者该居群在冰期经受的瓶颈作用更弱.高原台面东部间断分布的居群只固定Hap A,表明它们可能经历了冰期后共同的回迁过程和由此产生的奠基者效应.我们的研究结果表明祁连圆柏在冰期可能存在多个避难所,瓶颈效应和奠基者效应造成了这些居群现在的遗传多样性分布式样.

青藏铁路沿线高寒草原生态质量评价指标体系初探

为了全面和客观评价青藏铁路沿线高寒草原生态环境质量以及生态恢复工程的质量,在实地测定大量样方和统计分析的基础上,选取了盖度、物种多样性指数、丰富度指数、物种数、优势物种分盖度、土壤有机质含量、土壤深度等指标作为评价指标,制定了青藏铁路沿线高寒草原生态环境质量与生态恢复质量的评价指标值.该方法既反映了植被生态环境的量化指标,也考虑了与环境密切相关的植物生长立地表征指标,各项指标相互联系和相关,具有易获得性和实用性,符合当地生态环境质量现状,可以科学、客观地评价区域生态环境质量,对于指导青藏铁路建设中的生态建设与生态建设工程的质量具有实际的指导意义.