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31.
光照对东海赤潮高发区春季硅藻生长的影响 总被引：7，自引：0，他引：7
2005年3月在东海赤潮高发区的ZA3和ZC18b站通过现场培养探讨了光照对东海硅藻生长和演替的影响。培养期间,ZA3站优势种为中肋骨条藻,没有发生演替现象;ZC18b站,当光照低于6.7MJ.m-2.d-1,由角毛藻演替为中肋骨条藻,光照高于6.7MJ.m-2.d-1,角毛藻为第一优势种,浮动弯角藻为第二优势种。Logistic生长模型可以很好地描述不同光照下硅藻的生长状况,其拟和系数为0.92±0.03。终止生物量以及优势种生长速率与光照的关系表明,温度13.0℃左右,中肋骨条藻的最适生长光照为5.0MJ.m-2.d-1,角毛藻sp.和浮动弯角藻的最适生长光照均为6.7MJ.m-2.d-1。在富营养化条件下,光照是影响硅藻生长和演替的因子。 相似文献
32.
采用正交实验的方法,在光生物反应器中对纤细角毛藻 Chaetoceros gracilis的生长进行了研究,结果表明:光照强度、通气率对藻体细胞的生长具有显著的影响,在通气培养条件下,当培养密度较高时,纤细角毛藻细胞不仅能耐受超高光照强度的照射,而且还可以获得很高的生长速度。本实验条件下, -1 7经过 5 d的培养,细胞的比生长速率﹑生物量产量和细胞密度分别达到了 0.74 d ﹑1.13 g/L和 8.1×10 /mL的较高水平。 相似文献
33.
重金属胁迫对纤细角毛藻生长及叶绿素荧光特性的影响 总被引：2，自引：0，他引：2
研究了不同浓度的重金属离子(Cu2 ,Zn2 ,Cd2 )胁迫不同时间(24,48,72和96 h)后,纤细角毛藻生长及叶绿素荧光特性的变化情况.测定的主要参数有:PSII最大光能转化效率(Fv/Fm),PSII的潜在活性(Fv/Fo),PSII实际光能转化效率(Yield=ΦPSII),相对光合电子传递效率(rETR),光化学淬灭(qP)和非光化学淬灭(NPQ).实验结果表明,重金属离子(Cu2 ,Zn2 ,Cd2 )胁迫下纤细角毛藻的叶绿素荧光参数Fv/Fm,Fv/Fo,Yield和rETR均明显降低,并且随着重金属离子浓度的增加,胁迫时间的延长,下降幅度逐步增大;重金属胁迫下,细胞密度和叶绿素含量也显著降低.3种重金属离子的半抑制浓度(EC50)的计算结果表明,胁迫时间为24和48 h时,3种重金属离子对纤细角毛藻各叶绿素荧光参数(Fv/Fm,Fv/Fo,Yield,Chll content)的毒性大小顺序为Cu2 ＞Zn2 ＞Cd2 ;胁迫时间为72和96 h时,3种重金属离子的毒性大小顺序为Cd2 ＞Cu2 ＞Zn2 .本文还对叶绿素荧光技术在检测微藻对重金属胁迫敏感性中的应用进行了初步探讨. 相似文献
34.
The physiological responses of Nitzschia palea Kiitzing, a freshwater diatom, to elevated CO2 were investigated and compared with those of a marine diatom, Chaetoceros muelleri Lemmermann previously reported. Elevated CO2 concentration to 700 μl/L increased the dissolved inorganic carbon (DIC) and lowered the pH in the cultures of N. palea, thus enhancing the growth by 4%-20% during the whole growth period. High CO2-grown N. palea cells showed lower levels of dark respiration rates and higher Ik values. Light-saturated photosynthetic rates and photosynthetic efficiencies decreased in N. palea with the doubling CO2 concentration in airflow to the bottom of cultures, although the doubling CO2 concentration in airflow to the surface cultures had few effects on these two photosynthetic parameters. N. palea cells were found to be capable of using HCO3- in addition to gaseous CO2, and the CO2 enrichment decreased their affinity for HCO3- and CO2. Although doubled CO2 level would enhance the biomass of N. palea and C. muelleri to different extents, compared with the marine diatom, it had a significant effect on the specific growth rates of N. palea. In addition, the responses of photosynthetic parameters of N. palea to doubled CO2 concentration were almost opposite to those of C. muelleri. 相似文献
35.
36.
Fatty acid compositions of two strains of marine diatoms Nitzschia closterium(MACC B222)and Chaetoceros gracilis(MACCB13)have been examined.The microalgae have been grown at different initial NaNO3 concentrations(75,375,750,1125,1500,1875mg/L)and harvested at the late exponential phase.The results by one factor analysis of variance show that the NaNO3 concentrations have no significant influence on the relative growth rate of two stains of marine diatoms;the influence of NaNO3 concentrations on the fatty acids differs from species to species.The major fatty acids of two diatom strains are 14:0,16:0,16:In-7and 20:5n-3(EPA),B13 also has high percentage of 20:4n-6(6.0-9.1%). 相似文献
37.
小角刺藻生长过程中溶解游离氨基酸含量在海水中的变化 总被引：2，自引：1，他引：2
于1986年12月-1987年2月在温度为25±1℃下培养小角刺藻，以HPLC法测定该藻在培养过程中海水的溶解游离氨基酸（DFAA）含量变化。结果表明，小角刺藻不仅是海水中DFAA的主要生产者，而且也是DFAA的消耗者。小角刺藻不仅在缺乏硝酸盐的时候要吸收DFAA，即使在硝酸盐充足的情况下也会吸收。在小角刺藻的生长初期，水体中DFAA的含量迅速降低，而在后期却又大大增高。在小角刺藻的不同生长阶段，水体中DFAA的组成也不同。这些都可以说明海洋中DFAA的含量、组成和地区分布是密切地同浮游植物群落的繁殖消亡过程相关联的。 相似文献
38.
We report the results from a 250 km long transect, from the Danish coast to the North Sea at 55°30′ N, which was sampled every
32 km in order to study the composition and distribution of phytoplankton, and their dependence on the distance from the coast,
depth and other environmental factors. Altogether 144 species of algae were identified by light, epifluorescence and electron
microscopy. Some ecological preferences were found on the basis of measured environmental parameters and compared with the
literature. Possible controlling mechanisms for the distribution patterns of the plankton algae were analyzed by multivariate
statistics. Only distance from the coast was found to be a significant factor for algal distribution along the transect. Three
main areas of the transect were found: the coastal, middle and oceanic areas. Diatoms, mainly the centric ones, were the most
abundant group of algae. The other less abundant groups were Dinophyceae, Dictyochophyceae, Prasinophyceae and Chlorophyceae.
The pattern of distribution of diatoms and dinophytes along the transect was more or less similar, with larger numbers of
cells found close to both the eastern and western parts of the transect, although the species composition was different. Some
species were found to prefer coastal waters, other species were characterized as oceanic, and several species were found at
all stations. Porosira glacialis showed an atypical distribution along the transect, with highest abundances at both coastal and oceanic stations. 相似文献
39.
The physiological responses of Nitzschia palea Kvtzing, a freshwater diatom, to elevated CO2 were investigated and compared with those of a marine diatom, Chaetoceros muelleri Lemmermann previously reported. Elevated CO2 concentration to 700 μl/L increased the dissolved inorganic carbon （D!C） and lowered the pH in the cultures of N. palea, thus enhancing the growth by 4%-20% during the whole growth period. High CO2-grown N. palea cells showed lower levels of dark respiration rates and higher Ik values. Light-saturated photosynthetic rates and photosynthetic efficiencies decreased in N. palea with the doubling CO2 concentration in airflow to the bottom of cultures, although the doubling CO2 concentration in airflow to the surface cultures had few effects on these two photosynthetic parameters. N. palea cells were found to be capable of using HCO5 in addition to gaseous CO2, and the CO2 enrichment decreased their affinity for HCO5 and CO2. Although doubled CO2 level would enhance the biomass of N. patea and C. muelleri to different extents, compared with the marine diatom, it had a significant effect on the specific growth rates of N. palea. In addition, the responses of photosynthetic parameters of IV. palea to doubled CO2 concentration were almost opposite to those of C. muelleri. 相似文献
40.