Molecular iodine (I2) emission from two Laminaria species (Phaeophyceae) and impact of irradiance and temperature on I2 emission into air and iodide release into seawater from Laminaria digitata     

《Marine environmental research》2013

Kelps of the genus Laminaria accumulate iodine at high concentrations, but the iodine retaining capacity can be affected by emersion and physiological stress. In this study, I₂ emission into the atmosphere from Laminaria digitata and Laminaria hyperborea was compared under controlled low irradiances and temperatures. The two species exhibited different I₂ emission rates as blades of L. digitata emitted I₂ at rates five times higher than those from newly-grown blades (current growth season) of L. hyperborea. I₂ emission was not detectable from old blades (previous growth season) of L. hyperborea. Additionally, effects of irradiance and temperature on both I₂ emission into air and net I⁻ release into seawater where assessed for L. digitata while monitoring photo-physiological parameters as stress indicators. Irradiances between 30 and 120 μmol photons m⁻² s⁻¹ had only marginal effects on both I₂ emission and I⁻ release rates, but physiological stress, indicated by photoinhibition, was observed. The results suggest that the irradiances applied here were not stressful enough to impact on the iodine release. By contrast, at elevated temperatures (20 °C), photoinhibition was accompanied by an increase in I₂ emission rates, but net I⁻ release rates remained similar at 10–20 °C. High I₂ emission rates into air and I⁻ release into seawater observed from L. digitata underpin the fundamental function of this kelp as mediator of coastal iodine fluxes.  相似文献   

Comparison in copper accumulation and physiological responses of Gracilaria lemaneiformis and G. lichenoides (Rhodophyceae)     

黄鹤忠  梁建生  吴小松  张皓  李倩倩  张群英 《中国海洋湖沼学报》2013,31(4):803-812

Heavy metal pollution has become a worldwide problem in aquaculture. We studied copper (Cu2+ ) accumulation and physiological responses of two red algae Gracilaria lemaneiformis and Gracilaria lichenoides from China under Cu2+ exposure of 0-500 μg/L in concentration. Compared with G. lemaneiformis, G. lichenoides was more capable in accumulating Cu2+ , specifically, more Cu2+ on extracellular side (cell wall) than on intracellular side (cytoplasm) and in cell organelles (especially chloroplast, cell nucleus, mitochondria, and ribosome). In addition, G. lichenoides contained more insoluble polysaccharide in cell wall, which might promote the extracellular Cu2+ -binding as an efficient barrier against metal toxicity. Conversely, G. lemaneiformis was more vulnerable than G. lichenoides to Cu 2+ toxin for decreases in growth, pigment (chlorophyll a, chlorophyll b, phycobiliprotein, and β-carotene) content, and photosynthetic activity. Moreover, more serious oxidative damages in G. lemaneiformis than in G. lichenoides, in accumulation of reactive oxidative species and malondialdehyde, and in electrolyte leakage, because of lower antioxidant enzyme (superoxide dismutase and glutathione reductase) activities. Therefore, G. lichenoides was less susceptible to Cu2+ stress than G. lemaneiformis.  相似文献   

翘嘴鲌(Culter alburnus)TMEM-57基因的克隆、组织表达和单核苷酸多态性分析     

祁鹏志  郭宝英  谢从新  吴常文  陆诗敏  段友健 《海洋与湖沼》2012,43(6):1196-1201

采用RT-PCR和快速扩增cDNA末端(rapid amplification of cDNA ends,RACE)技术首次克隆了翘嘴鲌TMEM-57蛋白基因的cDNA全序列,该序列全长为2822bp,其中5′-UTR区93bp,3′-UTR区731bp,开放阅读框(open reading frame,ORF)为1998bp,编码665个氨基酸。NJ法系统进化分析将同科或属中TMEM-57基因分成一个分支,表现出种属间的高度保守性。利用荧光定量PCR(qPCR)技术检测了不同组织的表达量,发现在卵巢中表达量最高,其次为心脏和脑。用直接测序法对TMEM-57基因部分区段单核苷酸多态性(SNP)进行了检测,寻找到11个新的SNP位点。  相似文献   

Preliminary investigations on Arctic microalgae by joint aDDlication of fluorescent instruments     

ZHANG Fang  HE Jianfeng  GUANG Yingzhi 《极地研究(英文版)》2012,(2):128-132

In vivo fluorescence has a wide application in analyzing microalgae, including assessing phytoplankton biomass, rates of primary production and physiological status. This study describes a preliminary investigation on the joint application of the three kinds of fluorescence analysis in the physiological study of microalgae. Flow cytometry and fluorescence spectrometry were used to obtain the in vivo static fluorescence information of pigments, and a Pulsed-Amplitude-Modulation chlorophyll fluorometer was used to detect the dynamic fluorescence of chlorophyll. The validity of the joint application was proved by analyzing two labora- tory cultured Arctic microalgae, Pseudo-nitzschia delicatissima （Bacillariophyceae） and Thalassiosira sp. The higher value of minimum fluorescence yield in dark-adapted state （Fo）, actual photochemical efficiency of PSll （ФPSII）, and electron transport rate （ETR） exhibited positive results in a higher cell abundance and chlorophyll a content of P. delicatissima; whereas higher fl-carotene content of Thalassiosira sp. played an important role in the protection of photosynthesis.  相似文献   

海洋浮游植物三维荧光光谱的逐层分类方法研究     

李鸿羽  张前前  王修林  刘金涛  张凯临 《中国海洋大学学报(自然科学版)》2012,(Z2):117-125

提出活体海洋浮游植物三维荧光光谱逐层分类法,将浮游植物区分为不同的"光谱类别"。选取中国近海常见的26种分属于甲藻、硅藻、黄藻、金藻、隐藻、绿藻、蓝藻的浮游植物,在室温20℃和3个光照条件下培养,在第3,6,9,12,15天测其三维荧光光谱。采用主成份分析结合非负最小二乘回归法(NNLSR),以浮游植物叶绿素a的发射峰680nm所对应的激发光谱作为第一特征谱以区分门类,以EX730谱作为硅藻的逐层分类的第二特征谱,SY350谱作为甲藻的第二特征谱,将实验所用9种硅藻和8种甲藻各划分为3个光谱类别;分析405个浮游植物混合物,门类识别正确率大于94%,光谱类别的识别正确率为75%,该方法可用于海洋浮游植物种群结构变化的快速宏观监测。  相似文献   

Application of rRNA probes and fluorescence in situ hybridization for rapid detection of the toxic dinoflagellate Alexandrium minutum     

唐祥海  于仁成  周名江  于志刚 《中国海洋湖沼学报》2012,30(2):256-263

The dinoflagellate Alexandrium minutum is often associated with harmful algal blooms (HABs). This species consists of many strains that differ in their ability to produce toxins but have similar morphology, making identification difficult. In this study, species-specific rRNA probes were designed for whole-cell fluorescence in situ hybridization (FISH) to distinguish A. minutum from two phylogenetic clades. We acquired the complete SSU to LSU rDNA sequences (GenBank accession numbers JF906989-JF906999) of 11 Alexandrium strains and used these to design rRNA targeted oligonucleotide probes. Three ribotype-specific probes, M-GC-1, M-PC-2, and M-PC-3, were designed. The former is specific for the GC clade ("Global clade") of A. minutum, the majority of which have been found non-toxic, and the latter two are specific for the PSP (paralytic shellfish poisoning)-producing PC clade ("Pacific clade"). The specificity of these three probes was confirmed by FISH. All cells in observed fields of view were fluorescently labeled when probes and target species were incubated under optimized FISH conditions. However, the accessibility of rRNA molecules in ribosomes varied among the probe binding positions. Thus, there was variation in the distribution of positive signals in labeled cells within nucleolus and cytosol (M-GC-1, M-PC-3), or just nucleolus (M-PC-2). Our results provide a methodological basis for studying the biogeography and population dynamics of A. minutum, and providing an early warning of toxic HABs.  相似文献   

基于X射线荧光光谱法测定少量样品的主次元素     

张彩霞  孙忠 《中国沙漠》2012,32(5):1263-1267

在某些实验中,由于样品来源的有限性,导致样品数量有限,因而有必要探讨少量样品中主次元素的测定方法。X射线荧光光谱法具有样品制备简单、分析速度快、重现性好、测量范围宽和多元素同时进行分析的特点,目前在众多领域中得到了广泛的应用。基于回归曲线法、经验系数法和康普顿散射线内标法求取了各待测元素的工作曲线常数、元素间效应的影响系数和谱重叠系数,并对4 g(32 mm内径,常规)和1 g(10 mm内径,少量)样品测量的精密度和准确度进行了比较分析。结果表明,4 g(32 mm内径,常规)样品测量平均精密度约为1%,1 g(10 mm内径,少量)样品的平均精密度约为3%。测定结果基本能够满足覆盖区多目标地球化学调查样品的质量要求。  相似文献   

碳酸盐预分离-紫外脉冲荧光法快速测定高硬度地下水中微量铀     

付琳  王哲  王玉学  孙博 《铀矿地质》2017,(2):108-112

建立了碳酸盐预分离-紫外脉冲荧光法快速测定高硬度地下水中微量铀的方法。试验发现,预先向20.00mL高硬度水样中加入70mg·mL~(-1)的碳酸钠溶液1.20mL,将大部分共存的Ca~(2+)和Mg~(2+)以碳酸盐沉淀的形式与UO_2(CO_3)_2~(2-)有效分离后,应用紫外脉冲荧光法测量铀浓度,不但溶液保持澄清,pH值也可保持在7~9的约束范围之内。该预处理程序简单快速,测量结果准确可靠。方法的检出限为0.02μg·L~(-1),全程加标回收率在99%~101%之间,测量结果的相对标准偏差(RSD)小于5%。  相似文献   

两种盐生植物幼苗在NaCl处理下对昼夜温差变化的叶绿素荧光响应   总被引：3，自引：2，他引：1  

韩张雄  李利  徐新文  吕湘芳 《中国沙漠》2010,30(1):63-68

以囊果碱蓬(Suaeda physophora Pall.)、梭梭(Haloxylon ammodendron (C.A.Mey.) Bunge)两种植物幼苗为实验材料,研究了不同NaCl浓度处理下,一次昼夜温差（温差为27 ℃）变化对两种植物幼苗叶绿素荧光参数变化的影响。结果表明:①在NaCl胁迫下,同期囊果碱蓬的PSⅡ潜在活性Fv/Fo和最大光化学量子产量Fv/Fm降低幅度较小,而梭梭则有较明显降低,而且囊果碱蓬显著高于后者;同期光合量子产量Yield和表观光合电子传递速率ETR均以囊果碱蓬最大并显著高于梭梭,说明囊果碱蓬较梭梭具有强的对盐分和较大的昼夜温差变化的忍耐能力,其机体在盐分和较大昼夜温差变化下,并未受到较大的损伤,而梭梭的光合器官在相同的条件下却受到了较大的损伤,证明了囊果碱蓬更适合生长于同时具有盐渍和较大昼夜温差的地区。②通过实验发现梭梭的Yield值和ETR值到下午基本上能恢复到早上的水平,说明了其在前期的胁迫条件下,虽然光合器官上受到了破坏,但仍然能够通过光合调节适应环境的变化,以保持机体的活性。③囊果碱蓬在本实验条件下,光合器官虽然没有受到损伤,但200 mmol\5L-1 NaCl抑制了其光合能力。  相似文献   

盐分对胡杨幼苗生长及光合特性的影响   总被引：6，自引：2，他引：4  

李菊艳  赵成义  闫映宇  李君  孙栋元 《中国沙漠》2010,30(1):80-86

基于控制试验研究了盐分对胡杨实生幼苗生长及光合特性的影响。结果表明:①随着盐浓度增大,盐分对胡杨幼苗株高、基径及生物量影响明显,其程度大小为叶＞根＞茎。当土壤含盐量小于18.32 g·kg-1(50 mmol NaCl)时,该处理幼苗生物量比无盐处理Ⅰ(0 mmol NaCl)的减小了30%左右;当土壤含盐量达到27.95 g·kg-1 (200 mmol NaCl)时,该处理幼苗的生物量比无盐处理Ⅰ的减小了80%左右,幼苗难以正常生长。②盐分对胡杨幼苗的光合速率和水分利用效率影响显著。随着盐浓度增大,胡杨幼苗的净光合速率下降。当土壤含盐量小于18.32 g·kg-1时,胡杨幼苗可以通过降低蒸腾速率,提高自身的水分利用效率和耐盐性;当土壤含盐量大于18.32 g·kg-1时,胡杨幼苗的水分利用效率降低,幼苗生长表现出盐害症状。③随着盐浓度增大,盐分对胡杨幼苗的荧光特性影响明显,最大光化学效率（Fv/Fm）、PSⅡ的有效光化学量子效率（Fv′/Fm′）、光化学淬灭系数（qP）、电子传递速率（ETR）显著减小,非光化学淬灭系数（NPQ）呈增大趋势。  相似文献