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琼胶寡糖聚合度对坛紫菜抗性诱导的影响 总被引：2，自引：1，他引：1
研究了琼胶寡糖聚合度对坛紫菜抗性诱导的效应。以琼胶3,6和12糖,3种聚合度的琼胶寡糖为材料,处理坛紫菜,通过观察叶片腐烂率比较坛紫菜生长状态;利用透射电镜观察处理后的细胞亚显微结构变化;并检测坛紫菜附生菌的数量变化;以对羟基苯乙酸(POHPAA)化学发光法检测坛紫菜H2O2释放量;利用实时定量PCR检测坛紫菜NADPH氧化酶基因(Phrboh)的差异表达。结果表明,经琼胶3糖和6糖处理,坛紫菜的Phboh表达出现上调,并产生H2O2暴发。经两种琼胶寡糖处理后,坛紫菜的附生菌数量明显减少,其中以琼胶6糖的效果最好,在较长培养时间内,坛紫菜能保护自身细胞亚显微结构的完整性,维持良好的生长状态。而琼胶12糖没发现任何诱导作用。综上所述,聚合度为3和6的琼胶寡糖能诱导坛紫菜的抗性响应,特别是形成单个螺旋结构的琼胶6糖的诱导作用最明显,但聚合度较大的琼胶寡糖则不能。 相似文献
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中国江蓠属红藻所含琼胶的结构特征 总被引：4，自引：1，他引：4
用分级法和(13)~C-NMR研究了从中国产江蓠属红藻(真江蓠、细基江蓠、芋根江蓠和凤尾菜)提取的6份琼胶多糖的结构特征。这些琼胶主要由用0.5mol/L和1.0mol/LNaCl从DEAE-Sephadex A 50层析柱洗脱下的带电荷的琼胶糖分子组成。6.0mol/L尿素级分是带低电荷密度的琼胶糖分子。各级分总得率达80％或以上。(13)~C-NMR谱图表明各种江蓠琼胶的主要级分基本上由琼胶糖结构构成,但有的级分中琼胶糖含微量6-SO_4-L-半乳糖,真江蓠和细基江蓠的琼胶糖含有6-OCH_3-D-半乳糖,而凤尾菜琼胶中则主要含有2-OCH_3-3,6-内醚-L-半乳糖。真江蓠和凤尾菜的个别级分的琼胶酶降解产物与(13)~C-NMR分析结果相一致。 相似文献
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紫菜类红藻是亚洲沿海居民很久以来所喜爱的一种副食品。它含有丰富的矿物质、维生素、蛋白质(40％左右)和糖类(30％以上)。1961年,Turvey等提出脐形紫菜(Porphyra umbilicalis)所含多糖主要为紫菜胶(Porphyran)。 我国南方福建沿海大量人工养殖坛紫菜(P.haitanensis),主要用作副食品。近来有的生产单位用坛紫菜试生产琼胶(agar)。但关于坛紫菜多糖的化学结构究竟如何?是否是 相似文献
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茉莉酸甲酯和水杨酸对坛紫菜生长与抗逆性的影响 总被引：2，自引：0，他引：2
为了探讨植物激素在藻类生理与抗逆方面的作用,本文比较了不同浓度的茉莉酸甲酯(MJ)和水杨酸(SA)对坛紫菜(Pyropia haitanensis)生长、藻胆蛋白、可溶性蛋白、脯氨酸含量和叶绿素荧光参数的影响。结果显示100?mol/L SA的添加可使坛紫菜生长率达到对照组的1.57倍,而MJ对藻的生长影响不显著。50?mol/L MJ和100?mol/L SA显著促进了坛紫菜藻胆蛋白和可溶性蛋白的积累。50?mol/L MJ和100?mol/L SA添加后在48 h脯氨酸含量分别为对照组的2.67倍和1.75倍。25~50?mol/L MJ对坛紫菜的Fv/Fm和Y(II)影响不显著,而100?mol/L SA则可以提高这两个叶绿素荧光参数。该研究表明适当浓度的MJ和SA可以促进坛紫菜生长,提高其光合能力,在一定程度上增强坛紫菜的抗逆性。 相似文献
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坛紫菜与条斑紫菜轮栽试验 总被引：6，自引：0，他引：6
于1987—1989年利用人工培苗和潮间带栽培方法进行了坛紫菜和条斑紫菜轮栽试验。结果表明,用加大育苗室的采光面积、保温和缩短光照时间促熟措施,可使坛紫菜丝状体在8月初开始大量放散壳孢子,8—9月中旬采壳孢子苗,采苗后约35天开始采收紫菜,至12月初结束。9月中旬采苗的,亩产干品83.3kg。条斑紫菜丝状体按常规法育苗,于10月中旬采壳孢子苗,先在海上密挂育苗,至11月底取下坛紫菜网,将条斑网分挂到坛紫菜架上,进行了两种紫菜的轮换栽培,直至翌年5月初结束,亩产干品120.1kg。两种紫菜总产量达203.4kg,比单作增产近一倍。 相似文献
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采用不同浓度Zn2 处理坛紫菜叶状体,用紫外分光光度法,测定了光合色素的含量。研究了金属Zn2 对坛紫菜叶状体中光合色素:叶绿素a、藻红蛋白、藻蓝蛋白和别藻蓝蛋白的影响。结果表明:Zn2 在0.5~5.0μmol/L时,有利于光合色素的合成;但在5μmol/L时,叶绿素a含量开始下降,在Zn2 浓度>10μmol/L时各光合色素含量也随浓度的升高而下降,对光合色素产生毒害作用。除去Zn2 后,都表现出向对照组恢复靠近的趋势,但别藻蓝蛋白的恢复较慢。 相似文献
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紫菜在分类上属红藻门(Rhodophyta)、红藻纲(Phodophyceae)、红毛菜亚纲(Bangiophycidae)、红毛菜目(Bangiales)、红毛菜科(Bangiaceae)、紫菜属(Porphyra),全世界约有134种,广泛生长在全球海岸的潮间带,其栽培生产国主要分布在东南亚地区。中国北起辽宁省,南至海南省都有紫菜的分布,共记载过22个物种或变种,其中主要栽培品种有2个,北方的条斑紫菜(Porphyra yezoensis Ueda)和南方的坛紫菜(P.haitanensis Chang et Zheng)。 相似文献
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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
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The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding. 相似文献
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《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
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Hoi-Soo Jung Kap-Sik Jeong Yong-Shik Chu Sung-Hyun Park Ki-Hyune Kim 《Marine Georesources & Geotechnology》2001,19(3):181-195
Grain size and water content in box-core sediments from the Clarion-Clipperton fracture zone (C-C zone) in the northeast equatorial Pacific were analyzed in detail to understand the downcore variations across a hiatus between Quaternary and Tertiary layers. Grain-size distributions in the topmost core sediments show two modes: a coarse mode (peaked at 50 μm) and a fine mode (at 2-25 μm). The coarse mode disappears gradually with depth accompanied by the dissolution of siliceous fossil tests, whereas the fine mode coarsens due to the formation of authigenic minerals. Water content increases abruptly across a color boundary between an upper pale brown layer and a lower dark brown layer that is the hiatus between Quaternary and Tertiary layers. Abundant smectites and microvoid molds, which are created by the prolonged fossil dissolution in the underlying sediment, are attributed for the abrupt downcore variation of water content. Overall variations in grain size and water content in the topmost core sediments in the western C-C zone are possibly constrained by the dissolution of biogenic siliceous fossils. Variations in geotechnical properties related to these changes must be considered in the design of nodule collectors. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2001,24(1):27-33
This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake. 相似文献
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This study tests the hypothesis that the in situ void ratio of surficial marine sediments may be predicted from shear wave velocity-depth data with a reliability equal to that of other methods currently available. Shear wave velocity is fundamentally controlled by the number of grain-to-grain contacts per unit volume of material and by the effective stress across those contacts. In this study, three previously established empirical formulae are used to predict void ratio from velocity-depth data. Field data were acquired along a transect off the northern Californian coast across which water depth increased from 35 to 70 m and seafloor sediment type varied from sand to silty-sand, respectively. A towed seafloor sled device was used to collect shear wave refraction data, and a marked, systematic decrease in velocity was observed along the line, ranging from 35-70 m/s for the coarse, near-shore material to 25-40 m/s for the finer, offshore deposits. Void ratios predicted from these velocities were compared with data measured directly from box-core samples. Of the formulae used for prediction, two agree remarkably well with the control data. Both predicted and control values increase from 0.6-0.8 for the sandy material to 1.1-1.5 for the silty-sand. Thus, this study does not disprove the hypothesis set and demonstrates the potential of field shear wave velocity-depth data as a means of delineating spatial variation in void ratio for surficial marine sediments in a remote, nondestructive manner. 相似文献
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Particulate samples were collected from the Changjiang river system during a flood period, in May 1997, and POC, stable isotope and lipids associated with particles were examined. Results showed the decrease (0.84% ～ 1.88%) of organic carbon content from the upper reaches to the estuary.δ13C values of particulate organic carbon was in the range of -24.9×10-3 to -26.6×10-3, which were close to the isotopic signature of continental C3 vegetation. Total particulate n-alkanes concentrations varied from 1.4 to 10.1μg/dm3,or from 23.7 to 107μg/g of total suspended matter. Fatty acids were present in all the samples, from 1.4 to 5.4μg/dm3, with saturated and unsaturated straight-chain and branched compounds in the carbon number range from C12 to C30. Both δ13C and the ratio of carbon content to nitrogen content indicate the predominance of terrestrial inputs (soil organic matter) among the particles. The biomarker approach has been used to identify the relative portion of terrigenous and autochthonous fraction in the particulate samples. The distribution of fatty acids suggests a striking phytoplanktonic and microbial signal in most particle samples. The terrestrial alkanes are used to estimate the contribution of terrestrial inputs along the mainstream. 相似文献