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海筒螅中3种化学成分的分离鉴定 总被引：2，自引：0，他引：2
海筒螅（Tubuaria marina)的94%乙醇提取物，在水中混悬后，用石油醚萃取，石油醚相中的提取物经反复硅胶柱色谱分离和SephadexLH-20凝胶柱色谱分离，得到三个纯净的化合物。经^1HNMR,^13CNMR和DEPT谱鉴定，分别确定为二十一碳一烯，胆甾-5-烯-3β-醇和1-壬基-甘油醚。 相似文献
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用焦锑酸钙沉淀的电镜细胞化学方法，研究了白骨壤叶片衰老过程中叶肉细胞Ca^2 水平的变化．结果表明，在白骨壤幼叶和成熟叶叶肉细胞中，焦锑酸钙沉淀颗粒大量出现在液池和细胞间隙中，细胞壁中也可见少量沉淀，而细胞基质中则看不到焦锑酸钙沉淀．在衰老叶中，细胞基质和细胞膜上焦锑酸钙沉淀增加，而液泡和细胞间隙中的锑酸钙沉淀则显著减少，并且叶绿体外膜部分破损，结构破坏，核膜与液泡膜内部结构模糊，叶绿素含量、净光合速率、气扎手率和蒸腾速率显著下降．Ca^2 的区域性分布的变化与植物叶片衰老密切相关。 相似文献
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Salinity and periodic inundation controls on the soil‐plant‐atmosphere continuum of gray mangroves 
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下载免费PDF全文 Salinity and periodic inundation are both known to have a major role in shaping the ecohydrology of mangroves through their controls on water uptake, photosynthesis, stomatal conductance, gas exchanges, and nutrient availability. Salinity, in particular, can be considered one of the main abiotic regulating factors for halophytes and salt‐tolerant species, due to its influence on water use patterns and growth rate. Ecohydrological literature has rarely focused on the effects of salinity on plant transpiration, based on the fact that the terrestrial plants mostly thrive in low‐saline, unsaturated soils where the role of osmotic potential can be considered negligible. However, the effect of salinity cannot be neglected in the case of tidal species like mangroves, which have to cope with hyperosmotic conditions and waterlogging. We introduce here a first‐order ecohydrological model of the soil/plant‐atmosphere continuum of Avicennia marina—also known as gray mangrove—a highly salt‐tolerant pioneer species able to adapt to hyperarid intertidal zones and characterized by unique morphological and ecophysiological traits. The A. marina's soil‐plant‐atmosphere continuum takes explicitly into account the role of water head, osmotic water potential, and water salinity in governing plant water fluxes. A. marina's transpiration is thus modeled as a function of salinity based on a simple parameterization of salt exclusion mechanisms at the root level and a modified Jarvis' expression accounting for the effects of salinity on stomatal conductance. Consistently with previous studies investigating the physiology of mangroves in response to different environmental drivers, our results highlight the major influence of salinity on mangrove transpiration when contrasted with other potential stressors such as waterlogging and water stress. 相似文献
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揭示极端天气影响的红树林潮滩潮流能量耗散过程是理解生物海岸演变及滨海湿地生态修复工程的核心内容。以北部湾防城港东湾白骨壤红树林潮滩为例,基于声学多普勒流速仪（ADV）获取区域2020年8月连续6天的水动力和白骨壤红树林下垫面植被实测数据,分析白骨壤潮滩近底层动力响应台风“森拉克”的耗散过程。结果表明：1）正常天气涨、落潮期间,自光滩到白骨壤红树林林内近底层湍流动能变化具有潮汐不对称性特征。涨潮期间光滩—白骨壤红树林边缘、白骨壤红树林边缘—林内潮流挟沙能量分别通过泥沙沉降以及搬运泥沙两种方式沿程消耗,落潮期间潮流挟沙能量主要以泥沙净沉降的方式消耗。2）白骨壤通过其潮滩表层向上发育长约10 cm的呼吸根以降低湍流垂向紊动;红树林边缘的枝、叶通过影响水平方向上的水流动力,致使潮流挟沙能耗降低。3）与正常天气比较,台风“森拉克”期间东湾自光滩到白骨壤红树林林内近底层水体流速无明显变化,但流向偏转幅度明显变大。同时湍流动能的耗散率和用以搬运泥沙为主的潮流挟沙能耗亦均增大。 相似文献
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We report the first record of vertical rhizome growth in the temperate seagrass Zostera marina. In a population of Z. marina occurring on subtidal sand in the Novigrad Sea (Croatia), an area subject to episodic high sediment transport, collected plants of Z. marina showed vertical rhizomes with shorter and narrower inter‐nodes (mean length = 3.4 ± 1.5 SD mm, mean width = 1.9 ± 0.3 SD mm) than those recorded for horizontal rhizomes (mean length = 9.0 ± 3.5 SD mm, mean width = 2.8 ± 0.4 SD mm). Out of a sample of 1130 rhizome fragments, 288 (25.5%) were vertical. Repeated moderate burial events may have stimulated the production of vertical rhizomes, and the ability of Z. marina to produce vertical rhizomes may enable it to withstand moderate burial in this highly dynamic environment. 相似文献
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The purpose of this study was to investigate the antibacterial activity of extracts from Zostera marina against the pathogens of Apostichopus japonicus skin ulceration disease. When 95% ethanol (v/v) solvent was used to extract Zostera marina at 50°C, aqueous extract (ZA) showed obvious bacteriostatic effects on the tested bacterial strains (inhibition halo diameters
between 8.23 mm and 13.62 mm), whereas the ethyl acetate extract (ZE) was almost inactive. The minimal inhibitory concentration
(MIC) of ZA against four pathogens were homogeneous at 12.8 g L−1. ZA components were analyzed by thin layer chromatography (TLC) assay and six fractions were obtained. In another study,
the six fractions showed inhibitory effects against the tested bacteria while their functions seemed to counteract the ZA
activity. 相似文献
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LiZhenji ZhengWenjiao YangZhiwei LinYiming LinPeng 《海洋通报(英文版)》2003,5(2):40-53
The community characteristics of mangroves in the Futian Nature Reserve,Shenzhen, China are given based on surveying of 33 quadrats in 4 transects which stretch from the higher tidal zone to the lower tidal zone. The results show that there are 6 community types in this area: Kandelia candel association, Avicennia marina association, A egiceras corniculatum association, Kandelia candel Aegiceras corniculatum association,degiceras corniculatum Kandelia candel association and Acanthus ilicifolius association.Kandelia candel, degiceras corniculatum and dvicennia marina dominate the typicalquadrats. Kandelia candel can be seen at almost all quadrats, Aegiceras corniculatumdistributes mostly toward the estuary and the higher tidal zone, Avicennia marina distributesmostly toward the bay and the lower tidal zone, Bruguiera gymnorrhiza occasionally occurs toward the Estuary with one or several individuals, Acanthus ilicifolius was common towardthe higher tidal zone, as an accompanying species, Derris trifoliata was common in manymature ouadrats. Totallv. 6 snecies of man~rove plants and 3 soecies of semi-mangrove plants appear in this research area. From the higher tidal zone to the lower tidal zone, the average diameter and basal area of mangrove trees increase gradually. According to the results, the dvicennia marina dominates in average diameter and basal area, and the degicerascorniculatum trees are on the contrary. From the transect ! to the transect 4, the importance value ot dvicennia marina, Bruguiera gymnorrhiza and Kandelia candel decreases, and degiceras corniculatum increases. In this area, the Kandelia candel population and Ae giceras corniculatum population are developing populations with many seedlings and saplings, but the Avicennia marina population is in a mature stage with few seedlings and not so many total individuals. According to this research, we suppose that Aegiceras corniculatum should be developed toward the estuary and the dvicennia marina association should be protected. 相似文献
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The objectives of this study were to determine the distribution and abundance of Zostera marina (eelgrass) in relation to the distribution of the mat forming bacteria Beggiatoa spp., and the levels of sulfide and organic material (wood waste) in the sediment. Underwater videography and intertidal surveys were used to map the distribution and abundance of Z. marina beds and Beggiatoa in the nearshore area of Commencement Bay, WA (USA), a location that has a long history of sawmill activity. Zostera marina occurred from the intertidal to ?6 m mean lower low water (MLLW) on sandy substrates in areas with low levels of sulfide (<50 μm ) and organic material (<5 % total volatile solids). Areas with high sulfide levels (>200 μm ) occurred where there were significant amounts of organic material in the sediments, which was found to be wood waste that had been discarded from sawmills. Zostera marina was absent from the intertidal and occurred at lower densities in areas with high sulfide levels. In contrast, mats of Beggiatoa were only found in areas where the sulfide levels were >1000 μm and there were significant deposits of wood. Thus, the negative correlation between the distribution and abundance of Z. marina and Beggiatoa suggests that the presence of Beggiatoa mats could be used as a biological indicator of inhibiting levels of hydrogen sulfide in the marine environment. 相似文献
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Although copper (Cu) is an essential element for life, leaching from boat paint can cause excess environmental loading in enclosed marinas. The effects of copper contamination on benthic macrofaunal communities were examined in three San Diego Bay marinas (America's Cup, Harbor Island West and East) in Southern California, USA. The distribution of Cu concentration in sediments exhibited a clear spatial gradient, with hotspots created by the presence of boats, which in two marinas exceeded the effect range medium (ERM). Elevated sediment Cu was associated with differences in benthic assemblages, reduced species richness and enhanced dominance in America's Cup and Harbor Island West, whereas Harbor Island East did not appear to be affected. At sites without boats there were greater abundances of some amphipods such as the species Desdimelita sp., Harpinia sp., Aoroides sp., Corophium sp., Podocerus sp., bivalves such as Lyonsia californica, Musculista senhousia, Macoma sp., and polychaetes such as Diplocirrus sp. In contrast, at sites with boats, densities of Pseudopolydora paucibranchiata, Polydora nuchalis, Euchone limnicola, Exogone lourei, Tubificoides spp. were enhanced. The limited impact on Harbor Island East suggests not only lower Cu input rates and increased water flushing and mixing, but also the presence of adequate defense mechanisms that regulate availability and mitigate toxic impacts. At all three marinas, Cu in tissues of several macrobenthic species exhibited Cu bioaccumulation above levels found in the surrounding environment. The annelids Lumbrineris sp. and Tubificoides spp., and the amphipod Desdimelita sp. contained high levels of Cu, suggesting they function as Cu bioaccumulators. The spionid polychaetes Polydora nuchalis and Pseudopolydora paucibranchiata had much lower Cu concentrations than surrounding sediments, suggesting they function as Cu bioregulators. The macrobenthic invertebrates in San Diego Bay marinas that tolerate Cu pollution (e.g. P. nuchalis, P. paucibranchiata, Euchone limnicola, Typosyllis sp., Tubificoides sp.) may function as indicators of high‐Cu conditions, whereas the presence of Cu‐sensitive species (e.g. Podocerus sp., Aoroides sp., Harpinia sp., Macoma sp., Lyonsia californica) may indicate healthier conditions (less Cu‐stressed). Parallel responses by faunas of Shelter Island Yacht Basin, also in San Diego Bay, suggest potential for development of regional Cu contamination assessment criteria, and call for functional comparisons with other marinas and coastal water bodies. 相似文献