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本研究以海洋微藻——赤潮藻海洋卡盾藻(Chattonella marina)与饵料藻青岛大扁藻(Platymonas helgolandica var.tsingtaoensis)为研究对象,采用单培养和共培养的方法,研究二者间的竞争关系,并在此基础上研究海洋卡盾藻去藻过滤液和藻细胞裂解液对青岛大扁藻的化感作用,同时进一步探讨两种海洋微藻间的化感作用对UV-B辐射增强的响应。结果显示:共培养条件下,海洋卡盾藻在2个高浓度下对青岛大扁藻的生长产生显著抑制(P0.05);海洋卡盾藻去藻过滤液和藻细胞裂解液对青岛大扁藻的生长也具有显著抑制作用(P0.05),且藻细胞裂解液的抑制作用更强,说明海洋卡盾藻对青岛大扁藻产生化感作用,且通过细胞间直接接触传递的化感物质多于通过介质传递的。不同密度比例的2种藻共培养组用UV-B辐射(2.16J/m2)处理后,海洋卡盾藻对青岛大扁藻生长的化感作用有所减弱。 相似文献
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Green tides have occurred every year from 2007 to 2014 in the Yellow Sea. Ulva prolifera(Müller) J. Agardh has been identified as the bloom-forming alga,co-occurring with U. intestinalis. We observed distinct strategies for both algal species during green tides. U. prolifera exhibited a high abundance initially and then decreased dramatically,while U. intestinalis persisted throughout. The antioxidant system responses of these two macroalgae were compared in the late phase of a green tide(in-situ) and after laboratory acclimation. Lipid peroxidation and antioxidant system responses differed significantly between the two. Malondialdehyde and hydrogen peroxide contents increased significantly in-situ in U. prolifera,but not in U. intestinalis. In U. prolifera,we observed a significant decrease in total antioxidant ability(T-AOC),antioxidant enzymes(SOD and Apx),and non-enzyme antioxidants(GSH and As A) in-situ. U. intestinalis showed the same pattern of T-AOC and SOD,but its Gpx,Apx,and GSH responses did not differ significantly. The results suggest that U. prolifera was more susceptible than U. intestinalis to the harsh environmental changes during the late phase of a Yellow Sea green tide. The boom and bust strategy exhibited by U. prolifera and the persistence of U. intestinalis can be explained by differences in enzyme activity and antioxidant systems. 相似文献
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This paper aims to evaluate the effects of ultraviolet-Bradiation(UVBR) on Gracilaria lemaneiformis,a commercial red macroalga and an important source of agar. To study the in-vitro effect of UVBR on G. lemaneiformis,this plant was cultivated and exposed to photosynthetically active radiation(PAR) at 40 μmol photons/(m2 ·s) and enhanced UVBR(0,0.36,0.72,1.08,1.44,and 1.80 k J/(m 2 ·d)) for 13 days. The samples were processed for histochemical analysis,and the growth rate,photosynthetic pigment contents,photosynthetic performance,reactive oxygen species levels,membrane permeability,malonyl dialdehyde contents and antioxidant capacity of G. lemaneiformis were investigated. After 13 days of exposure to PAR+UVBR,G. lemaneiformis showed photodamage and photoinhibition of photosynthetic pigments(chlorophylla and phycoerythrin),leading to a decreased photosynthetic efficiency. Further,there was a corresponding decrease in the relative growth rates and depigmentation and partial necrosis of the apical segments were noted after exposure to PAR+UVBR. Additionally,UVBR induced excess production of superoxide radicals and hydrogen peroxide,eliciting a marked cellular membrane damage and antioxidative response. 相似文献
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With the increased use of copper(Cu)-based antifouling(AF) paints,copper has become a potential threat to marine organisms. Experiments were performed to investigate the effects of copper on larvae of the barnacle Chthamalus challengeri. These experiments attempted to identify a more sensitive index to monitor copper pollution in marine environments. The 24 h LC5 0 ranged from 156.07 μg/L(nauplius II) to 817.15 μg/L(cypris) and the no observed effect concentration(NOEC) ranged from 81.75 μg/L(nauplius II) to 571.04 μg/L(cypris). The cypris settlement rate declined significantly when copper concentrations ≥135 μg/L. No cypris was found in the copper concentration of 60 and 75 μg/L treatment groups stressed for 22 d. Nauplius II moulting was not affected by exposure to copper for 24 h; however,when extended to 48 h,the percent moulted in 75 μg/L treatment group was declined to 37.12%,which was significant lower( P 0.05) than that in the control group. The phototaxis of nauplius II decreased significantly when copper concentrations ≥45 μg/L. Despite an initial significant increase at copper concentrations of 30 μg/L,ammonia excretion rate decreased when copper concentrations ≥60 μg/L. These results suggested that:(1) nauplius II could not develop to the cypris when the copper concentration ≥60 μg/L;(2) cypris settlement is more susceptible to copper than cypris mortality rate;(3) nauplius II is the most sensitive larval stage;(4) nauplius II ammonia excretion rate is the most sensitive index to copper and might be as the indicator for copper pollution monitoring. 相似文献
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The present study was conducted to determine the ef fects of elevated pCO_2 on growth, photosynthesis, dark respiration and inorganic carbon acquisition in the marine microalga D unaliella salina. To accomplish this, D. salina was incubated in semi-continuous cultures under present-day CO_2 levels(390 μatm, p HN BS : 8.10), predicted year 2100 CO_2 levels(1 000 μatm, p HN BS : 7.78) and predicted year 2300 CO_2 levels(2 000 μatm, p H NBS : 7.49). Elevated pCO_2 significantly enhanced photosynthesis(in terms of gross photosynthetic O_2 evolution, ef fective quantum yield(ΔF/F' m), photosynthetic efficiency( α), maximum relative electron transport rate(r ETRm ax) and ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco) activity) and dark respiration of D. salina, but had insignificant effects on growth. The photosynthetic O_2 evolution of D. salina was significantly inhibited by the inhibitors acetazolamide(AZ), ethoxyzolamide(EZ) and 4,4'-diisothiocyanostilbene-2,2′-disulfonate(DIDS), indicating that D. salina is capable of acquiring HCO ˉ 3 via extracellular carbonic anhydrase and anion-exchange proteins. Furthermore, the lower inhibition of the photosynthetic O2 evolution at high pCO_2 levels by AZ, EZ and DIDS and the decreased carbonic anhydrase showed that carbon concentrating mechanisms were down-regulated at high pCO_2. In conclusion, our results show that photosynthesis, dark respiration and CCMs will be af fected by the increased pCO_2/low p H conditions predicted for the future, but that the responses of D. salina to high pCO_2/low p H might be modulated by other environmental factors such as light, nutrients and temperature. Therefore, further studies are needed to determine the interactive eff ects of pCO_2, temperature, light and nutrients on marine microalgae. 相似文献
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黄家沟泥石流的基本特征及成因分析 总被引:3,自引:0,他引:3
黄家沟是一条具有较强活动性的泥石流沟,对富泉集镇新址构成了较大的安全隐患,文章针对其基本特征及成因进行了分析。 相似文献
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