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1.
不同藻类对温度与磷叠加作用的响应模式 总被引：1，自引：1，他引：0
气候变暖对富营养化引起的蓝藻水华扩张具有叠加作用,为探索不同藻类对气候变暖与富营养化叠加作用的响应模式,选用富营养化水体常见藻类铜绿微囊藻(Microcystis aeruginosa)、水华鱼腥藻(Anabaena flos-aquae)和斜生栅藻(Scenedesmus obliquus)作为材料,采用室内培养方法,模拟春末不同升温幅度(20+3、23+3和20+6℃),5个磷浓度水平(0、0.05、0.15、0.30和0.50 mg/L),通过生长速率、光化学参数等的测定,分析不同藻类对温度升高和营养盐添加的生长与光化学响应.结果表明:3种藻的生长速率对温度和磷的叠加作用呈现不同的响应模式:随着磷浓度的升高,铜绿微囊藻的生长速率受温度的叠加作用不断增加,26℃时差异最大;水华鱼腥藻生长速率除在0.30 mg/L磷浓度时受温度叠加作用比较明显外,其他磷浓度水平均没有显著的叠加效应;斜生栅藻在不同磷浓度水平下受温度叠加作用影响有较大波动,但无明显差异.铜绿微囊藻对温度的叠加作用随着磷浓度的增加呈现逻辑斯蒂模式增长,而水华鱼腥藻和斜生栅藻均是在特定温度或特定营养盐浓度时呈现最大的叠加作用,叠加作用的趋势不明显.从Fv/Fm结果可知,铜绿微囊藻下降幅度明显高于水华鱼腥藻和斜生栅藻,随温度升高,磷浓度越高,铜绿微囊藻的Fv/Fm下降幅度越大,这可能是铜绿微囊藻在高生长速率下色素无法积累所致;水华鱼腥藻的Fv/Fm基本保持稳定,各组间差异较小;斜生栅藻的Fv/Fm在低磷浓度组明显低于高磷浓度组,并且随温度升高下降趋势增加,3种藻的光学特性响应反映了藻类在叠加作用下生长的变化.综上所述,铜绿微囊藻对温度上升与磷浓度的升高有更强的响应,导致其产生更高的生长速率,从而促进了蓝藻水华的扩张. 相似文献
2.
用粒径小于100 μm的泥沙分别配置浊度为30、60和90 NTU(Nephelometric Turbidity Units)的混浊水体,将穗花狐尾藻(Myriophyllum spicatum L.)成体植株分别种植于上述水体中,2个月后,利用水下饱和脉冲荧光仪(Diving-PAM)测定植株叶片的叶绿素荧光参数.结果表明,水体悬浮泥沙对狐尾藻成体植株Fv/Fm和Fo影响不显著,植株PSⅡ无显著损伤.用30 μmol photon/(m2·s)的光化光照射10 s,在30和60 NTU的混浊水体中植株△Fv/Fm、qP和rETR与对照的差异不显著;在90NTU的水体中,qP、rETR与对照的差异显著(P＜0.05);qN值≤0.1,表明在低光化光照射下叶片的热耗散少,能量更多的参与了光化学反应.在悬浮泥沙水体中植株的rETR日变化幅度显著小于对照,植株的光合作用随水体浊度的增加显著降低.Fv/Fm日变化呈较为平缓的"V"形变化,植株受到的光抑制程度低;泥沙浊度≥60 NTU时,Fv/Fm恢复变慢,但与对照差异不显著.rETRmax随泥沙浊度升高呈下降趋势,光合作用能力显著降低.结果表明穗花狐尾藻是一种较为耐受悬浮泥沙水体的沉水植物,悬浮泥沙对植株光合系统PSⅡ、抗光抑制能力无显著影响,但对光合作用能力影响显著(P＜0.05). 相似文献
3.
温度、光照强度及硝酸盐对拟柱孢藻(Cylindrospermopsis raciborskii N8)生长的影响 总被引：4，自引：3，他引：1
以从南亚热带水库中分离的拟柱孢藻(Cylindrospermopsis raciborskii N8)为材料,研究了不同温度(12、16、20、24、28、32℃)、光照强度(6.6、12.4、21.5、30.7、62.9、106.4μmol/(m2·s))和硝态氮浓度(0.5、1、2、4、8、16、32、64、128 mg/L)下拟柱孢藻的生长特性.结果表明:在实验设置的温度范围(16~32℃)内拟柱孢藻能够正常生长;最适温度范围为24~28℃,在28℃条件下,具有最大比生长速率,为0.189 d-1;当温度为12℃时,拟柱孢藻叶绿素a浓度一直降低,显著低于其他温度组(16~32℃).在6.6~106.4μmol/(m2·s)光照强度范围内,拟柱孢藻均呈指数增长趋势,最适光照强度为30.7μmol/(m2·s),其比生长速率达到最大值,为0.156 d-1;高光照强度(62.9~106.4μmol/(m2·s))下拟柱孢藻的比生长速率显著大于低光照强度(6.6~12.4μmol/(m2·s))处理组.拟柱孢藻开始指数增长的最低硝态氮浓度为4 mg/L;硝态氮浓度为8 mg/L时,拟柱孢藻达到最大比生长速率(0.155 d-1);当硝态氮浓度高于16 mg/L时比生长速率增加不显著.高硝态氮浓度组(16~128 mg/L)拟柱孢藻的叶绿素a浓度和比生长速率显著高于低硝态氮浓度组(0.5~2 mg/L).研究结果说明拟柱孢藻对温度、光照和氮源均有较宽的生态位,有利于在较大空间尺度上进行扩散. 相似文献
4.
运用水下饱和脉冲荧光仪(Diving-PAM)测定附着了水网藻的亚洲苦草(Vallisneria asiatica)叶片的荧光参数和快速光响应曲线.在水网藻主要附着的苦草叶片上部,15 d后Fv/Fm显著下降,光系统(PS)的光化学效率显著降低;附着水网藻的叶片通过热的形式耗散掉的能量极显著增加(P＜0.01),有效荧光产量、光化学淬灭系数和相对光合电子传递速率(rETR)、Chl.a、类胡萝卜素(Car)、Chl.a/Chl.b和Car/Chl.a均显著降低;在快速光响应曲线中,当光照强度高于104 μmol/(m2·s)后,随光照强度的增加,附着水网藻的苦草叶片的rETR显著低于对照,光合作用能力下降;且其饱和光强为248μmol/(m2·s),显著低于对照叶片的685 μmol/(m2·s),表明水网藻附着苦草叶片后导致叶片光响应能力显著下降. 相似文献
5.
水华鱼腥藻是常见的有害水华藻种,但其在磷、光强、温度等生境要素协同作用下的生长动力学鲜见报道.本研究在Lehman模型、Steele模型基础上,设置8个PO3-4-P梯度:0、0.1、0.2、0.5、0.75、1.0、2.5、5.0μmol/L,4个温度水平:15、20、25和30℃和4个光强水平:1000、2000、3000和5000 lx,采取单因素实验方法进行水华鱼腥藻室内纯培养.Monod模型表明水华鱼腥藻最适生长温度和光强条件分别是20℃和3000 lx,最大比生长速率(μmax)和半饱和常数(KS)分别为0.447 d-1和0.081μmol P/L;分别用Lehman模型和Steele模型模拟水华鱼腥藻μmax在不同磷浓度下对连续变化的温度和光强的响应,Lehman动力学模拟结果表明水华鱼腥藻的最适生长温度为21.22±0.98℃,μmax和KS分别为0.421±0.011 d-1和0.055±0.009μmol P/L;Steele模型结果表明μmax和KS分别为0.461±0.010 d-1和0.051±0.009μmol P/L,水华鱼腥藻最适生长光强Ik为2650.93±88.19 lx. 相似文献
6.
通过室内纯培养,分别设定不同温度梯度(14、16、18℃)和光照梯度(100、250、360 μmol/(m2·s)),以模拟全球气候变化条件下,温带湖泊春季温度升高与光照减弱交互作用对铜绿微囊藻和蛋白核小球藻生长和光合活性的影响.通过流式细胞计数测定其生长曲线,观测其变化趋势,并利用叶绿素荧光仪PHYTO-PAM测定藻类光合活性.结果表明,当温度为18℃,光强为100μmol/(m2·s)时,铜绿微囊藻生长速率最大,细胞密度达到2.99×106cells/ml.在该温度和光照强度下,其光合活性也远高于其他实验组,其Fv/Fm值达到最大值0.39.蛋白核小球藻在温度为16和18℃时,其生长速率差异不大,但明显高于在温度为14℃时的生长速率,其光合活性处于波动状态.与蛋白核小球藻相比,温度升高和光照减弱对铜绿微囊藻生长和光合活性的促进作用更为明显,而且随着温度的升高,铜绿微囊藻生长对低光的偏好更为显著.因此,全球变暖所导致的高温低光环境可能有利于确立铜绿微囊藻在湖泊中的优势地位. 相似文献
7.
为了研究重金属镉对藻类光合系统毒性效应及能量分配特征,以拟柱孢藻(Cylindrospermopsis raciborskii)为研究对象,分析了不同镉浓度下拟柱孢藻的生长、单位叶绿素a含量、光合系统Ⅱ(PSⅡ)叶绿素荧光及其能量分配模型.结果表明:不同浓度镉培养拟柱孢藻96 h后,0.2 mg/L Cd~(2+)对拟柱孢藻单位细胞叶绿素a含量及PSⅡ活性无显著影响,而0.5mg/L Cd~(2+)培养时拟柱孢藻的单位细胞叶绿素a含量为对照组的62.97%.当Cd~(2+)浓度高于5 mg/L时,拟柱孢藻的PSⅡ活性受到抑制并导致表征量子产额分配的φEo和ψo分别下降了15.35%和13.52%.此外,当Cd~(2+)浓度高于5 mg/L时,藻体PSⅡ能量分配表现为TRO/CSm和ETO/CSm显著减小,DIO/CSm差异不显著,类囊体能量分配表现为ABS/RC、TRO/RC和DIO/RC显著增大,明显区别于0.2、0.5和1 mg/L Cd~(2+)处理组.这些结果表明PSⅡ反应中心是镉对拟柱孢藻光合作用影响的重要作用位点,且Cd~(2+)高于5 mg/L时显著影响了拟柱孢藻PSⅡ反应中心并且抑制了PSⅡ电子传递链供体侧的电子传递,而拟柱孢藻则可能通过改变PSⅡ的能量分配来保护和缓解镉对其光合结构的损伤. 相似文献
8.
我国水华蓝藻的新类群——阿氏浮丝藻(Planktothrix agardhii)生理特性 总被引：3，自引：2，他引：1
阿氏浮丝藻(Planktothrix agardhii)是水华蓝藻的重要类群,实验对我国不同省份分离到的5株阿氏浮丝藻生长速率、色素组成、光合活性参数进行了测定.结果表明分离于广州的HABll28叶绿素a(Chla)含量较低,藻蓝蛋白(c-Pc)比例和含量较高.电子传递速率(ETR)测定结果表明,HABIl28的ETR曲线较高,最大ETRme值也显著高于其余4株,高效的光能电子传递链弥补了光合色素Chla的不足,以致HABIl28保持了中性的生长速率.分离于武汉东湖的HAB631则与之正好相反,较高的ChLa受限于光能电子传递链的薄弱,生长速率表现较低.分离于北京、上海、昆明的3株藻株在各项生理指标上无显著差异. 相似文献
9.
利用自行研制的光生物反应器,以水库中典型的铜绿微囊藻(Microcystis aeruginosa)和斜生栅藻(Scenedesmus obliquus)为研究对象,研究了两种藻类在光照强度周期性波动条件下的抑制特性.结果表明,相对恒定时平均光照强度6100 lx而言,在光照强度周期性波动条件下,在培养至24天时,铜绿微囊藻生物量降低14%、颜色稍黄,斜生栅藻生物量降低24%、藻体严重泛黄;铜绿微囊藻的叶绿素a和类胡萝卜素含量分别降低12.7%和55.5%,斜生栅藻的叶绿素a和类胡萝卜素含量分别降低78%和74%;模拟内波的周期性波动光强下,两种藻的光合作用参数Fv/Fm、YⅡ和ETR下降,热耗散量NPQ增高,且光合作用受到抑制,生长代谢能力减弱,这为内波控藻提供了理论依据. 相似文献
10.
11.
We have studied the effect of light acclimation on photosynthetic responses and growth during Cu2+ exposure (0–0.84 μM) in the brown seaweed Fucus serratus. Measurements of chlorophyll fluorescence parameters showed that Cu2+ exposure amplified ETR, reduced the chlorophyll content at the cellular level and that there was no effect of light adaptation on the Cu2+ resistance of the algae. In contrast to the inhibitory effects of Cu2+ on chlorophyll fluorescence, O2 evolution and the total content of chlorophyll and carotenoid of the algae was unaffected by Cu2+. We conclude that photoinhibition and perhaps pigment degradation in the meristoderm was compensated for by cells deeper in the thallus with the result that the overall photosynthetic fitness of the algae was maintained. The pronounced inhibitory effects of Cu2+ on algae growth was not a consequence of photoinhibition and could be attributed to direct inhibitory effects on the growth process. 相似文献
12.
We have studied the effect of light acclimation on photosynthetic responses and growth during Cu2+ exposure (0–0.84 μM) in the brown seaweed Fucus serratus. Measurements of chlorophyll fluorescence parameters showed that Cu2+ exposure amplified ETR, reduced the chlorophyll content at the cellular level and that there was no effect of light adaptation on the Cu2+ resistance of the algae. In contrast to the inhibitory effects of Cu2+ on chlorophyll fluorescence, O2 evolution and the total content of chlorophyll and carotenoid of the algae was unaffected by Cu2+. We conclude that photoinhibition and perhaps pigment degradation in the meristoderm was compensated for by cells deeper in the thallus with the result that the overall photosynthetic fitness of the algae was maintained. The pronounced inhibitory effects of Cu2+ on algae growth was not a consequence of photoinhibition and could be attributed to direct inhibitory effects on the growth process. 相似文献
13.
《Acta Geochimica》2021,(4)
If the photosynthetic organisms assimilated only CO_2 in the Archean atmosphere,hydroxide ion in the Archean seawater would not increase.If plants would not consume bicarbonate as a direct substrate during photosynthesis,it is difficult to explain the evolution of Earth's environment.To date,it is generally accepted that photosynthetic O_2 evolution of plants come from water photolysis.However,it should be debated by evaluating the effect of bicarbonate in photosynthetic O_2 evolution,analyzing the role of carbonic anhydrase(CA) in photosynthetic O_2 evolution,and the relationship between thylakoid CA and photosynthetic O_2 evolution.In the paper,I propose that bicarbonate is directly used as substrate to participate in photosynthetic O_2 evolution.The rationality of bicarbonate photolysis of plants is discussed from the thermodynamics and evolution of Earth's environment.The isotopic evidence that bicarbonate is not the direct substrate of photosynthetic O_2 release is reexamined,and the new explanation of bicarbonate photolysis in photosynthetic O_2 evolution is proposed. 相似文献
14.
Gao Y Fang J Zhang J Ren L Mao Y Li B Zhang M Liu D Du M 《Marine pollution bulletin》2011,62(8):1628-1631
The impact of the widely used herbicide atrazine on seedling growth and photosynthesis of eelgrass was determined. The long-term impact of the herbicide atrazine (1, 10 and 100 μg/L) on growth of eelgrass Zostera marina (L.) seedlings, maintained in outdoor aquaria, was monitored over 4 weeks. Exposure to 10 μg/L atrazine resulted in significantly lower plant fresh weight and total chlorophyll concentration and up to 86.67% mortality at the 100 μg/L concentration. Short-term photosynthetic stress on eelgrass seedlings was determined and compared with adult eelgrass using chlorophyll fluorescence. The effective quantum yield in eelgrass seedlings was significantly depressed at all atrazine concentrations (2, 4, 8, 16, 32 and 64 μg/L) even within 2 h and remained at a lower level than for adult plants for each concentration. These results indicate that atrazine presents a potential threat to seagrass seedling functioning and that the impact is much higher than for adult plants. 相似文献
15.
《Acta Geochimica》2016,(3)
The strong adaptability of Broussonetia papyrifera(L.) Vent. to low phosphorus(P) conditions can be attributed to the large amount of root-exuded organic acids and the high ef?ciency of P extraction. However,microelement contents are in?uenced by low-P stress, and their effects on the photosynthetic capability of B. papyrifera remain unknown. In this study, we investigated the effects of low-P treatment on net photosynthetic rate(P_N);chlorophyll a ?uorescence(ChlF) characteristics; and Fe,Mn, Cu, and Zn contents of B. papyrifera and Morus alba L. seedlings. Results show that B. papyrifera exhibited better photosynthetic capability under moderate P de?-ciency(0.125, 0.063, and 0.031 mmol/L P treatments),whereas the photosynthetic capability of M. alba decreased under moderate and severe P de?ciency(0.016 and0 mmol/L P treatments). Under moderate P de?ciency, the decrease in Cu and Zn contents in B. papyrifera was lower than that in M. alba. Under severe P de?ciency, a considerable decrease of photosynthetic capability in B. papyrifera and M. alba was associated with low Cu and Zn contents. The P N of the two Moraceae species exhibited a better correlation with Cu and Zn contents than with Fe or Mn content. P de?ciency could not only decrease cyclic photophorylation and photosynthetic ef?ciency, but could also affect the stability of thylakoid membrane structure and electron transport ef?ciency by in?uencing the contents of Cu or Zn, thereby affecting photosynthesis. 相似文献
16.
Tolerance and accumulation of copper in the salt-marsh shrub Halimione portulacoides 总被引：1，自引：0，他引：1
Cambrollé J Mancilla-Leytón JM Muñoz-Vallés S Luque T Figueroa ME 《Marine pollution bulletin》2012,64(4):721-728
The present study evaluated the tolerance and accumulation potential in the salt-marsh shrub Halimione portulacoides under moderate and high external Cu levels. A greenhouse experiment was conducted in order to investigate the effects of a range of external Cu concentrations (0 to 60 mmol l(-1)) on growth and photosynthetic performance by measuring gas exchange, chlorophyll fluorescence parameters and photosynthetic pigments. We also determined total copper, nitrogen, phosphorus and sulfur concentrations in the plant tissues. H. portulacoides survived with external Cu concentrations of up to 35 mmol Cu l(-1), although the excess of metal resulted in a biomass reduction of 48%. The effects of Cu on growth were linked to a drastic reduction in net photosynthesis. However, H. portulacoides tolerated Cu levels of up to 15 mmol Cu l(-1) without suffering adverse physiological effects. Our results indicate that this species could play an important role in the restoration of Cu-contaminated soils. 相似文献
17.
Optical properties of benthic photosynthetic communities: fiber-optic studies of cyanobacterial mats
A fiber-optic microphobe was used to analyze the spectral light gradients in benthic cyanobacterial mats with 50-micrometer depth resolution and 10-nm spectral resolution. Microcoleus chthononplastes mats were collected from hypersaline, coastal ponds at Guerrero Negro, Baja California. Gradients of spectral radiance, L, were measured at different angles through the mats and the spherically integrated scalar irradiance, Eo, was calculated. Maximal spectral light attenuation was found at the absorption peaks for the dominant photosynthetic pigments: chlorophyll a at 430 and 670 nm, carotenoids at 450-500 nm, phycocyanin at 620 nm, and bacteriochlorophyll a at 800-900 nm. Scattered light had a marked spectral effect on the scalar irradiance which near the mat surface reached up to 190% of the incident irradiance. The spherically integrated irradiance thus differed strongly from the incident irradiance both in total intensity and in spectral composition. These basic optical properties are important for the understanding of photosynthesis and light harvesting in benthic and epiphytic communities. 相似文献
18.
好氧不产氧光合细菌（aerobic anoxygenic photosynthesis bacteria，AAPB）是广泛分布于海洋、湖泊及河流等典型水域生境中的异养原核生物，能够以环境中有机物为营养物质来获取细胞生长及代谢所需的能量，同时借助自身独特的菌绿素完成光合作用产能但不合成氧气，在物质循环与能量流动中扮演着重要角色.近年，越来越多的AAPB种属被陆续报道，基于光合基因，例如光合反应中心M亚基（pufM）的分子系统发育分析显示，大部分AAPB属于α-、β-及γ-变形菌，且丰度及多样性随生境的不同而呈现时空地理格局异质性.本文对AAPB的栖息环境与生长特性、丰度与分布、生态功能以及环境驱动因子等方面的研究进展进行了回顾和综述.目前，针对水库生态系统AAPB的研究鲜见报道，作者建议开展水库生境中AAPB多样性分布、环境驱动因素及生态功能研究，丰富对于水生生态系统中功能微生物种群生态结构与代谢功能的认识. 相似文献
19.
Salinity is a vital factor that regulates leaf photosynthesis and growth of mangroves, and it frequently undergoes large seasonal and daily fluctuations creating a range of environments – oligohaline to hyperhaline. Here, we examined the hypotheses that mangroves benefit opportunistically from low salinity resulting from daily fluctuations and as such, mangroves under daily fluctuating salinity (FS) grow better than those under constant salinity (CS) conditions. We compared growth, salt accumulation, gas exchange, and chlorophyll fluorescence of leaves of mangrove Bruguiera gymnorhiza seedlings growing in freshwater (FW), CS (15 practical salinity units, PSU), and daily FS (0–30 PSU, average of 4.8 PSU) conditions. The traits of FS-treated leaves were measured in seedlings under 15 PSU. FS-treated seedlings had greater leaf biomass than those in other treatment groups. Moreover, leaf photosynthetic rate, capacity to regulate photoelectron uptake/transfer, and leaf succulence were significantly higher in FS than in CS treatment. However, leaf water-use efficiency showed the opposite trend. In addition to higher concentrations of Na+ and Cl−, FS-treated leaves accumulated more Ca2+ and K+. We concluded that daily FS can enhance water absorption, photosynthesis, and growth of leaves, as well as alter plant biomass allocation patterns, thereby positively affecting B. gymnorhiza. Mangroves that experience daily FS may increase their adaptability by reducing salt build-up and water deficits when their roots are temporally subjected to low salinity or FW and by absorbing sufficient amounts of Na+ and Cl− for osmotic adjustment when their roots are subsequently exposed to saline water. 相似文献
20.
Photosynthetic pigments and peroxidase activity as indicators of heavy metal stress in the Grey mangrove, Avicennia marina (Forsk.) Vierh 总被引：2，自引：0，他引：2
Mangroves have been observed to possess a tolerance to high levels of heavy metals, yet accumulated metals may induce subcellular biochemical changes, which can impact on processes at the organism level. Six month-old seedlings of the grey mangrove, Avicennia marina (Forsk.) Vierh, were exposed to a range of Cu (0-800 micrograms/g), Pb (0-800 micrograms/g) and Zn (0-1000 micrograms/g) concentrations in sediments under laboratory conditions, to determine leaf tissue metal accumulation patterns, effects on photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoids), and the activity of the antioxidant enzyme peroxidase. Limited Cu uptake to leaves was observed at low sediment Cu levels, with saturation and visible toxicity to Cu at sediment levels greater than 400 micrograms/g. Leaf Pb concentrations remained low over a range of Pb sediment concentrations, up to 400 micrograms/g Pb, above which it appeared that unrestricted transport of Pb occurred, although no visible signs of Pb toxicity were observed. Zn was accumulated linearly with sediment zinc concentration, and visible toxicity occurring at the highest concentration, 1000 micrograms/g Zn. Significant increases in peroxidase activity and decreases in photopigments were found with Cu and Zn at concentrations lower than those inducing visible toxicity. Significant increases in peroxidase activity only, were found when plants were exposed to Pb. Positive linear relationships between peroxidase activity and leaf tissue metal concentrations were found for all metals. Significant linear decreases in photosynthetic pigments with increasing leaf tissue metal concentrations were observed with Cu and Zn only. Photosynthetic pigments and peroxidase activity may be applicable as sensitive biological indicators of Cu and Zn stress, and peroxidase activity for Pb stress in A. marina. 相似文献