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1.
江苏近岸紫菜养殖筏架区定生绿藻群落结构及其受控因素 总被引：3，自引：1，他引：2
基于2010年10月至2011年4月对苏北紫菜养殖筏架区定生绿藻及环境因素调查数据,分析研究了紫菜筏架上定生绿藻种群结构和数量变化及重要环境因子对其的影响并估算了调查区绿藻总生物量.结果表明,筏架上定生绿藻种类有浒苔(Ulva prolifera)、盒管藻(Capsosiphon groenlandicus)、缘管浒苔(Ulva linza)、肠浒苔(Ulva intestinalis)、条浒苔(Ulva clathrata)和扁浒苔(Ulva compressa).绿藻生物量变化呈倒抛物线型,4月份为主高峰14898吨,11月份为次高峰2034吨,2月份最低,仅为729吨,3-4月份绿藻几乎呈暴发性增长.种类多样性随季节变化有很大差异,养殖筏架刚入海的9、10月份,绿藻种类丰富,生物多样性高;12月至笠年2月,尽管生物量很低,但仍是多种并存;3-4月份随着生物量的猛增,种类多样性降至最低,盒管藻优势地位明显,生物量比例最大能到80%,浒苔比例呈指数增长,达20%～40%.水温对绿藻生物量及种类演替有直接调控作用,在水温< 10℃时,绿藻即能快速生长;而盐度作用不明显.开展紫菜筏架上定生绿藻群落动态变化及其生物量的估算,为追溯南黄海大规模绿潮发源地提供佐证,为绿潮预防和治理提供基础数据支撑. 相似文献
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双壳类适应性进化遗传基础尚未有大量研究。而生活在沿海潮间带和深海环境中的双壳贝类适应性进化的分子机制更鲜有报道。我们首次测序组装了潮间带生活的偏顶蛤Modiolus modiolus的转录组序列。同时与生活在深海热液冷泉喷口的偏顶蛤Bathymodiolus platifrons进行了比较转录组分析，阐明了这两个物种在不同环境中的适应性进化机制。M. modiolus和B. platifrons的转录组组装共产生182，476和156，261个转录本，N50值分别为1，769和1，545。同时注释到27，868和23，588个基因。GO富集分析表明这些基因有相似的富集模式。两物种进化分析鉴定到10，245个直系同源基因，其中26个基因受到强烈正选择（Ka/Ks＞1），12个基因受到中度正选择（0.5M. modiolus的转录组组装拼接序列，同时通过比较转录组学分析阐明了其与近缘物种B. platifrons的适应性进化机制。这为两个物种后续研究提供了序列资源和研究基础。 相似文献
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三酰基甘油(甘油三酯)是生物体内主要的碳和能量储存形式，也是细胞膜和信号分子的重要组成部分，它们在多种生理过程和环境胁迫响应中发挥重要作用。酰基辅酶A:二酰基甘油酰基转移酶(DGAT)催化真核生物甘油三酯合成途径中最后一步和唯一的酰基化步骤。本研究从绿潮浒苔中鉴定并获得了一个新的二酰基甘油酰基转移酶UpDGAT1基因，并在酿酒酵母甘油三酯缺失合成四重突变体中通过异源表达验证了该基因的功能。薄层色谱和BODIPY染色结果表明，浒苔UpDGAT1基因能够恢复酵母中甘油三酯的合成和脂质体的形成。酵母细胞的脂肪酸组成分析显示，浒苔UpDGAT1具有广泛的底物特异性，可接受饱和、单不饱和和多不饱和酰基辅酶A作为底物。高盐度和高温胁迫增加了浒苔UpDGAT1基因的表达和浒苔甘油三酯的积累。本研究为进一步解析UpDGAT1在浒苔甘油三酯积累和胁迫响应中的作用提供了基础。 相似文献
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生物学研究及种类鉴定是绿潮研究的热点和难点之一.本文系统阐述了石莼科绿藻常见种类的生物学特征,探讨了系统分类研究难点,并利用ITS、rbcL等基因序列以及质体蓝素氨基酸序列进一步研究分析了石莼科10种绿藻的序列结构特征和分子系统学关系.研究显示,石莼科浒苔属和石莼属绿藻rbcL和ITS序列差异未体现出属间分化的差异,根据rbeL序列和ITS序列分别构建的系统进化树中,石莼和孔石莼、肠浒苔、扁浒苔都聚类到同一进化枝上,而裂片石莼和网石莼、浒苔和缘管浒苔聚类到另一进化枝上,这显示出在分子进化水平上较为一致的结果,为浒苔属和石莼属系统分类深入研究提供一定的证据;根据质体蓝素所构建的系统进化树中,阿氏石莼和孔石莼在NCBI上发表的质体蓝素氨基酸序列在第1进化枝中,浒苔的质体蓝素氨基酸序列在第2进化枝中.但在第1进化枝中,孔石莼的3个质体蓝素氨基酸序列没有完全分布在同一个分支上. 相似文献
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采用PCR方法，将扩增的产物直接测序，测定了孔石莼Ulva pertusa和浒苔Enteromorpha prolifeFa的5．8S rRNA基因序列，与肠浒苔、扁浒苔、缘管浒苔、礁膜、北极礁膜、袋礁膜和格氏礁膜等7种已知的大型海洋绿藻的同一基因序列合并进行比较，分析了核苷酸序列差异和碱基替换特点，并构建系统发生树。结果表明，浒苔和孔石莼的颠换率为0．690％，小于浒苔与肠浒苔、扁浒苔、缘管浒苔的颠换率；且浒苔与孔石莼之间的Kimura双参数距离也小于浒苔与肠浒苔、扁浒苔以及缘管浒苔之间的平均Kimura双参数距离。相对于浒苔属的其他物种，浒苔与孔石莼的亲缘关系更近。在构建的系统发生树中，缘管浒苔与孔石莼聚为一类，表现出与石莼属物种更近的亲缘关系。 相似文献
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近年来，海水富营养化导致近海海域大型海藻过量繁殖，成为世界性的环境问题。自2007年以来，浒苔绿潮在黄海海域连续暴发，造成巨大经济损失。为探究浒苔大规模暴发与氮磷比值(N/P)的关系，及其与其他大型绿藻在不同N/P下的竞争机制，研究了浒苔(Ulva prolifera)与石莼(Ulva lactuca)在不同N/P下单独培养和共培养时的生长情况，探究了浒苔及石莼生长的变化；结合苏北浅滩海域现场N/P的调查结果，分析了浒苔绿潮暴发的可能机制。研究结果表明:(1)浒苔单独培养时，在一定范围内高N/P能促进浒苔的生长，氮对于浒苔的影响大于磷。(2)石莼单独培养时，低N/P下石莼长势最好，但改变N/P对石莼的影响并不显著。(3)浒苔和石莼共培养时，浒苔生长受到了一定限制，低N/P下浒苔生长受限更显著。(4)苏北浅滩海域高N/P更适合浒苔的生长，可能是浒苔绿潮能够大规模暴发的原因之一。 相似文献
7.
苏北浅滩沉积物中的大型绿藻微观繁殖体的垂直分布和物种多样性 总被引：1，自引：0，他引：1
本研究通过在2017年秋冬季组织实施的2个绿潮种源调查航次,研究苏北浅滩紫菜养殖区沉积物中的大型绿藻微观繁殖体的垂直分布和物种多样性。对沉积物中的微观繁殖体的定量实验结果表明:表层泥样中绿藻微观繁殖体的丰度最高,随着深度的增加迅速降低。在9月份表层沉积物中丰度为9±2ind./g,而在11月份表层丰度达到98±25ind./g;与9月份相比, 11月份浅滩沉积物中绿藻繁殖体数量呈现出显著升高的趋势。通过对51个绿藻样品的分子鉴定发现:沉积物中存在石莼属(Ulva)、尾孢藻属(Urospora)、盘苔属(Blidingia)等大型绿藻的微观繁殖体;数量占优是石莼属繁殖体,主要包括曲浒苔(Ulva flexuosa)、浒苔(Ulva prolifera)、扁浒苔(Ulva compressa)、缘管浒苔(Ulva linza);其中曲浒苔占据的比例最高,在9和11月份分别达到80.94%和73.33%。在2个调查航次中,都从沉积物中发现了绿潮浒苔的微观繁殖体,这些微观繁殖体是绿潮浒苔在苏北浅滩种源维持的重要方式和关键阶段,也构成了黄海浒苔绿潮连年暴发的"种子库"。 相似文献
8.
本文研究了3种抗生素联合处理黄海绿潮浒苔(Ulva prolifera)形态及共附生细菌多样性的影响。将浒苔放散的配子加入到含有3种广谱抗生素(青霉素G、硫酸新霉素、多黏菌素B)的培养液中进行培养, 与对照组相比, 发现浒苔幼苗生长速度缓慢, 且细胞变小, 藻体无法形成正常形态。进一步采用16S rDNA高通量测序分析抗生素处理藻体前后的共附生细菌多样性, 发现抗生素处理后浒苔共附生细菌丰富度和多样性降低, 其中Maribacter丰度降低。将藻体与形态发生化合物thallusin(Maribacter spp. 提取物)共培养, 发现thallusin可促进藻体形态恢复和生长, 推测抗生素可通过抑制Maribacter等细菌从而影响浒苔形态和生长, 这将为浒苔共附生细菌功能的深入研究奠定一定基础。 相似文献
9.
超微粉碎浒苔(Enteromorpha prolifera)对花鲈生长、非特异性免疫及消化酶活性的影响 总被引：2，自引：0，他引：2
浒苔(Enteromorpha prolifera)是绿藻门(Chlorophyta)石莼科(Ulvaceae)的一属, 因水体富营 养化等原因而大量繁殖, 危害海洋生态系统, 同时富含营养物质和活性物质, 具有提高机体免疫、促 进动物生长和加快机体营养物质代谢等功能。本研究以超微粉碎技术加工浒苔, 以水产经济鱼种花 鲈(Lateolabrax japonicus)为研究对象, 分6 个浓度梯度(0%, 1%, 2%, 3%, 4%, 5%), 研究浒苔对花鲈 生长性能、非特异性免疫及消化酶活性的影响, 结果显示: 4%组显著降低了花鲈鱼体水分含量及肝 指数(HSI), 显著提高了鱼体粗蛋白含量(P<0.05); 3%组显著提高了花鲈的增重率(WGR)、特定生长率 (SGR)、胃肠组织中蛋白含量(TP)、肠道中蛋白酶、淀粉酶(AMS)、脂肪酶(LPS)活力以及胃LPS 活 力(P<0.05), 而显著降低了胃组织中AMS 和蛋白酶活力(P<0.05), 同时3%组显著提高了花鲈肝脏中 碱性磷酸酶(AKP)活力以及TP 含量, 血清中AKP、超氧化物歧化酶(T-SOD)、溶菌酶(LSZ)活力 (P<0.05), 显著降低了肝脏中谷丙转氨酶(GPT)和谷草转氨酶(GOT)活力(P<0.05).本研究认为, 饲料 中添加超微粉碎浒苔能够明显提高花鲈的生长性能、肠道消化酶活力及非特异性免疫力, 且最佳添 加量为3%.本研究可为其变废为宝, 缓解绿潮带来的环境压力, 研发新型饲料添加剂, 提高水产养 殖经济效益提供理论基础。 相似文献
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11.
From 2007 to 2011, large-scale green tides formed by unattached filamentous alga, Ulva prolifera in Ulva linza–procera–prolifera complex, have initially occurred in Jiangsu coasts of China. The real niche or the substrate(s) on which U. prolifera attaches before it starts to float is still under debate. However, great numbers of Ulva propagules would be supposed to exist in the microscopic, overwintering stage for the next spring's bloom in coastal environments. This study was designed to confirm the above prediction and investigate abundance, species composition and growth characteristics of Ulva propagules in the sediments. Quantification result showed that Ulva propagules widely distributed in the sediments and the abundance of these isolates did not change much over a 3-month testing period at low temperature in darkness. Molecular data based on three DNA markers revealed that four Ulva species existed in the sediments, among which green-tide forming alga, U. prolifera, was included. Elevated levels of temperature, irradiance as well as nutrients in seawater greatly facilitated recovery and growth of propagules. Results of this investigation indicated the possibility of microscopic propagules turning directly into floating biomass in season when temperature, irradiance and nutrients together meet the required levels in questioned coastal water area. 相似文献
12.
Existence of a deep subtidal stock of drifting Ulva in relation to intertidal algal mat developments
Blooms of drifting green algae often develop in shallow coastal zones that receive significant nutrient inputs. Each spring and summer, some fifty bays and coves in Brittany (France) are affected in this way. Until now, in this region, only the algae present in the surf zone or stranded ashore, constituting an intertidal stock, have been taken into account. Another stock of algae, which was subtidal and of the same species (Ulva spp.), was found in the Bay of Douarnenez, one of the ten areas most affected by these algal blooms. This subtidal Ulva stock was located beyond the surf zone, at depths reaching 15 m. It was about the same size as the intertidal stock, viz., a few thousand tons on average. Subtidal Ulva stocks were generally found lying on the sandy bottom in a distribution showing no particular pattern. Biomass ranged from almost zero to 1.547 kg m−2 of fresh and spun-dried algae. However, at depths from 3 to 7 m they were often arranged in strips a few dm wide, due to the swell's effect. The bottom conditions of temperature, salinity, irradiance and dissolved inorganic nitrogen measured during spring and summer are suitable for the growth of Ulva in the subtidal zone. Both intertidal and subtidal drifting Ulva stocks are mobile and capable of exchanging material. In spring, the intertidal stock's inoculum is likely to come from the subtidal. Later in the season, the subtidal stock could be supplied, at least partially, by the intertidal. 相似文献
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Ulva species can grow rapidly in nutrient-rich habitats causing green tides and marine fouling. A more complete understanding of the reasons behind these outbreaks is urgently required. Accordingly, this study attempts to use microsatellite markers based expressed sequence tag（EST） to analyze the genetic variation of several Ulva prolifera populations in the South Yellow Sea of China. Two hundred and thirty-eight SSRs were identified from 8 179 unique ESTs（6 203 newly sequenced and 1 976 downloaded from NCBI database） and 37 primer pairs were successfully designed according to the ESTs; 11 pairs were selected to detect the genetic diversity and relationship of 69 attached U. prolifera samples and 13 free-floating samples collected from coastal and off-coast areas of the South Yellow Sea. The results of cross-species transferability showed that six of the 11 EST-SSR primers could give good amplification in other five Ulva species and the average allele number was 4.67. Genetic variation analysis indicated that all 82 U. prolifera samples were clearly divided and most samples collected from the same site clustered together as a group in the dendrogram tree produced by unweighted pair-group mean analysis（UPGMA） method and the cluster results showed some consistency with the geographical origins. In addition, 13 free-floating samples（except HT-001-2） were grouped as a single clade separated from the attached samples. 相似文献
14.
Florence Mamboya Thomas J. Lyimo Tommy Landberg Mats Bjrk 《Estuarine, Coastal and Shelf Science》2009,84(3):326-330
The influence of salinity on growth and Cu uptake in the green macroalga Ulva reticulata collected from the intertidal area in the Western Indian Ocean was studied under controlled laboratory conditions. Exposure concentrations ranged from 5 to 500 μg Cu l−1 at five salinities (ranging 20–40). The accumulation of Cu increased with decreasing salinity, so that the uptake at 500 μg Cu l−1 was approximately 2.7, 2.4 and 2.0 times higher at salinities of 20, 25, and 30 respectively, than uptake at salinity of 35, and with uptake being lowest at salinity of 40. Ulva maintained a positive growth rate over the whole salinity range (20–40), with highest rates at salinity of 35. When exposing to Cu at low salinities (20 and 25), the growth rate of Ulva was strongly inhibited suggesting an increase in toxicity of Cu with decreasing salinity. EC50 and NOEC increased with increase in salinity, implying a reduced Cu toxicity at high salinities. It was concluded that salinity needs to be considered when using macroalgae, such as U. reticulata, as a bioindicator of heavy metals in areas with heavy rainfall, underground fresh water intrusion or in estuaries, as they might accumulate more metals and be more negatively affected. 相似文献
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黄海绿潮源自苏北浅滩,暴发后期浒苔向北漂移至山东半岛南岸,会集中释放大量微繁体。虽然构成严重的繁殖体压力,但尚未发生大面积定生。为了明确漂浮生态型浒苔北侵定居的关键限制因素,本研究于2015年7月漂浮浒苔在青岛沿海大量堆积期间,采集潮间带表层沉积物样本,分别在盐度25和32下进行培养,试验不同盐度对漂浮生态型浒苔微繁体萌发和幼苗生长的影响。进一步通过单藻种培养,分析漂浮生态型与定生浒苔群体、以及青岛定生近缘种缘管浒苔对盐度的适应性差异。结果表明,盐度对微繁体萌发与幼苗生长两个阶段均构成重要影响,但具有不同的影响方式。在萌发阶段,单藻培养条件下,盐度对浒苔各群体和缘管浒苔的萌发率均无显著影响,但在混合培养条件下,盐度则通过种间竞争对萌发率产生显著影响,青岛的高盐条件更加有利于当地种,而苏北海域的低盐条件会显著提高漂浮生态型的萌发率。在幼苗的生长阶段,盐度可直接产生影响,高盐条件显著降低浒苔所有群体幼苗的生长率,对缘管浒苔则无显著影响,表现明显的种间差异。上述结果提示,盐度与种间竞争的协同作用可能是限制漂浮生态型浒苔大规模北侵定居的重要因素,这为预测漂浮生态型的扩散范围与黄海绿潮的变异趋势提供了理论依据。 相似文献
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Nereis diversicolor is generally considered to be a predator and deposit feeder, but have also been found to graze on benthic algae in shallow coastal areas. In this study we investigated the grazing effects on the development and growth of green algae, Ulva spp. Algal growth was studied in an experiment including two levels of sediment thickness; 100 mm sediment including macrofauna and 5 mm sediment without macrofauna, and three treatments of varying algal biomass; sediment with propagules, sediment with low algal biomass (120 g dry weight (dwt) m− 2) and sediment with high algal biomass (240 g dwt m− 2). In the 100 mm sediment, with a natural population of macrofauna, N. diversicolor was the dominating (60% of total biomass) species. After three weeks of experimentation the result showed that N. diversicolor was able to prevent initial algal growth, affect growth capacity and also partly reduce full-grown algal mats. The weight of N. diversicolor was significantly higher for polychaetes in treatments with algae added compared to non-algal treatments. There were also indications that a rich nutrient supply per algae biomass counteracted the grazing capacity of N. diversicolor. 相似文献
17.
利用2009-2018年在南黄海苏北浅滩海域的现场调查数据，分析和研究了该海域漂浮绿藻和马尾藻的长期变化和季节性波动特征。研究显示，漂浮绿藻于每年4月中旬至下旬在浅滩中部筏架周围开始出现。5月－6月，漂浮绿藻生物量迅速增加，并漂移扩散至深水区。漂浮绿藻密度年际变化较大，但这十年间总体呈上升趋势。相比较而言，漂浮马尾藻仅在2013、2017和2018年在浅滩聚集形成春季藻华；且这三年，漂浮马尾藻密度超过同期漂浮绿藻。浅滩漂浮马尾藻的发生与发展过程与漂浮浒苔明显不同。3月，漂浮马尾藻开始出现于浅滩离岸海域，4-5月，漂浮马尾藻大量侵入浅滩，因此浅滩漂浮马尾藻现并非起源于本地。受高强度人类活动以及浅滩以外海域物理化学和生物过程的影响，浅滩环境因素与漂浮绿藻生物量的关系不甚明确。对于漂浮马尾藻的起源以及与漂浮绿藻的相互关系也需要进一步研究。 相似文献
18.
长毛对虾是我国南方沿海地区的重要经济虾类。近年来,由于过度捕捞、病害频发以及海洋环境恶化,长毛对虾的自然资源量大幅减少。为补充自然资源,改善种群结构,1980年我国开始对长毛对虾开展增殖放流工作。然而,增殖放流的效果如何,目前尚缺乏有效的评估手段。以长毛对虾为实验材料,通过对其基因组进行de novo测序和重测序开发SNP (single nucleotide polymorphism)标记,最终建立长毛对虾的亲子鉴定技术。具体研究结果如下:长毛对虾基因组大小为1 335.76 Mb GC (guanine cytosine)含量为40.86%,N50为1 221 bp;以组装的长毛对虾基因组为参考基因组通过重测序进行SNP挖掘,共获得12 579 780个原始SNP位点,经筛选,优化及模型选择,最终建立了基于192个SNP标记的长毛对虾亲子鉴定技术,亲子鉴定成功率为100%(95%的置信度)。研究结果可为下一步长毛对虾增殖放流效果评估提供参考。 相似文献
19.
Macroalgae are useful organisms to monitor the environmental quality and to detect impacts due to anthropogenic activities. However, it is very important to identify the scales of variation in natural assemblages, particularly for the detection of environmental impacts. Otherwise, changes due to anthropogenic impacts may be confused with differences due to natural temporal variability. Another important task is to determine the appropriate level of taxonomical effort needed to detect changes in the assemblage structure. Many taxonomical surrogates, at higher taxonomic levels than that of species, have been proposed but, the consistence in space and time of the results produced by surrogates with those obtained at specific level should be tested. The objectives of this study are to identify the seasonal patterns of tidepool macroalgal communities using objective procedures and to test the consistence between the patterns obtained considering data at the species level and functional groups. Results showed that the seasonal pattern obtained using functional groups and species was consistent. Tidepool macroalgal assemblages showed a seasonal pattern with significant differences between spring–summer and autumn–winter. This pattern can be explained by changes in environmental variables and the seasonal development of the dominating species. Ulva spp. and the non-indigenous species Grateloupia turuturu were the species responsible for this pattern due to their high seasonality in terms of biomass. Finally, the abundance and species diversity within the corticated functional group was proposed as indicator of environmental impacts due to its relatively constant abundance and its sensitivity to environmental impacts. 相似文献
20.
海藻共附生细菌密切参与宿主的生长发育、营养吸收等重要过程,浒苔(Ulva prolifera)是构成黄海绿潮的唯一优势种,对其共附生细菌开展群落结构分析,有望为成灾机制研究提供重要线索。由于植物叶绿体基因组同时具备原核特征和高拷贝数,会严重干扰共附生细菌基于16S rDNA的序列扩增。高等植物中开发了通用引物799F,利用其3′末端与植物同源区的非配对双碱基,可实现对细菌来源序列的特异性扩增。本文针对多个浒苔群体样本,首次评价了引物799F在藻类中的适用性,发现799F的3′末端与浒苔叶绿体同源区仅存在非配对单碱基,其扩增仍会受到浒苔叶绿体严重干扰。在引物799F的基础上,设计了新引物800F,与通用反向引物1492R配对扩增细菌16S rDNA中具高分辨率的V5-V9可变区,配合使用具热启动功能、同时不具校对功能的DNA聚合酶,可基本完全避免浒苔叶绿体来源序列的扩增,并阐明了方法的原理。优化的引物扩增方案可用于浒苔共附生细菌群落结构分析。 相似文献