Chlorophyll concentration

Recently, the ocean-basin distribution of marine biomass and productivity has been estimated by satellite remote sensing. Ocean color at different wavelengths is determined and used to estimate near-surface phytoplankton chlorophyll concentration. Production is then estimated from chlorophyll using either in situ calibration relationships or from empirical functional algorithms (e.g., Platt and Sathyendranth, 1988 Field et al., 1998). Such studies reveal a tremendous amount of temporal and spatial variability in ocean biological production. 

Kopsell, D.A. et al.. Variation in lutein, P-carotene and chlorophyll concentrations among Brassica oleracea cultigens and seasons, Hort. ScL, 39, 361, 2004. 

Planktonic chlorophyll increased from the upper reaches of the main section to the meandering zone of the Ebro Depression, and sharply decreased after the large reservoirs located in the lower reaches. On the basis of the chlorophyll concentration, the river Ebro can be defined as eutrophic [15]. Plankton chlorophyll levels ranged between 10 and 17 pg/L from the headwaters to the city of Zaragoza, and then increased up to 60 pg/L in the meander plain (Fig. 2a). Suspended chlorophyll in the Ebro ranged between 10 and 30 pg/L in most of the sites... 

Fig. 2 Planktonic chlorophyll concentration along the main course of the Ebro river during the periods 2005-2006 (a) and 2008-2009 (b). Values are means of the chlorophyll samples taken in triplicate at each sampling time and in the different sampling sites...

Differences in chlorophyll concentrations between present and past records in the lower part of the Ebro do not correspond with significant changes in the distribution of phytoplankton assemblages. The general trends in the distribution of phytoplankton communities appear to be consistent with those reported in previous surveys, at least in the lower part of the river. Centric diatoms such as Aulacoseira granulata, Cyclotella sp. and Stephanodiscus sp. were dominant in autumn, spring, and early summer 1989-1990, while Scenedesmus sp., Coelastrum sp., and Pediastrum sp. were most abundant in the summer of that period [7]. 

Chloroplasts. Intact chloroplasts were isolated from freshly harvested growth chamber-grown spinach (Splnacla oleracea L.) as described by Lilley and Walker (10). Thylakoids were prepared by the method of Armond t al. (11). Chlorophyll concentrations were determined by the method of MacKinney (12). Photochemical reactions yere conducted at 25°C with a photon fluence rate of 750... 

Species That Produce Pigments in Response to Ozone. Ozone causes pigment changes in many plant species. Chlorophyll degradation occurs and chlorosis results. In one plant, Rumex crispus L., chlorophyll concentrations did not decrease but anthocyanin synthesis was increased after exposure to ozone ( ). 

Therefore, the reaction constant evaluated from the variation of ao2 with the concentration of allylthiourea has been taken as kejk9 + Au[S]/fc9. However, no experiments with different chlorophyll concentrations have been reported in order to show the dependence of this constant on [S]. 

Chlorophylls are also present in many oleoresins. By fractionation of fennel oil in two separators in series, the pigments precipitate in the first separator [80]. The effects of the extraction parameters on chlorophyll concentration are shown in Table 9.6-4. Increasing extraction pressure and/or temperature favour the dissolution of the pigments. 

Chloroplasts will be isolated by careful extraction of spinach leaves, using tricine buffer containing sucrose. The crude extract contains both whole and fragmented chloroplasts, but both contain all the necessary photosyn-thetic components and are capable of photophosphorylation. The preparation described in this experiment retains almost all of the chlorophyll in the chloroplasts. The total chlorophyll content of the chloroplasts will be determined by extracting the pigment with aqueous acetone and measuring the absorption at A. = 652 nm. The chlorophyll concentration is calculated according to Equation E9.3 (Arnon, 1949),... 

The average range of chlorophyll concentration for the described chloro-plast preparation is 0.3 to 1.0 mg/mL. For an alternative method of measuring chlorophyll and other pigment concentrations in plant extracts, see Experiment 8. 

The experimental arrangement is shown in Figure E9.3. Maintain the temperature of the water bath at 10°C by adding ice. Add a trace of CuS04 solution to the water bath to eliminate infrared radiation from the lamp. Obtain a test tube that will hold the pH electrode and 10 to 15 mL of solution. Dilute the chloroplast solution with suspension buffer to a chlorophyll concentration of about 300 /rg/mL. Adjust the pH meter with standard pH 7 buffer. The following three experimental conditions are recommended. Each condition should be tested individually and done in duplicate. 

Run appropriate chlorophyll standards. Calculate chlorophyll concentrations from generated peak integration data according to the response curves for each specific standard. 

There is now the possibility of estimating the carbon budget by using data of satellite observations of ocean color made with SeaWiFS and MODIS instruments calibrated by comparing them with observations by the Marine Optical Buoy (MOBY) (Lavender et al., 1998, 2005 Pinkerton et al., 2003). Calibration ensures that errors in the retrieval of chlorophyll concentration in seawater do not exceed 6%, which makes it possible to substantially raise the reliability of estimates of primary production and, hence, of the carbon budget. 

Residence time is defined as the ratio of the mass of a scalar to the rate of renewal of the scalar under steady-state conditions. Residence times are commonly used to better understand variability in biogeochemical processes such as nutrient fluxes, chlorophyll concentrations, primary production, and benthic faunal production. 

Effect of (-)-usnic acid (- -) and (+)-usnic acid (-o-) (0.03 - 100 pM no data for 0.1 m-M) on chlorophyll concentration in lettuce cotyledons after 6 days of growth. 

Chlorophyll was extracted from 40 mg of leaf tissue per treatment in 3 mL of dimethyl sulfoxide.19 Total chlorophyll concentration was determined spectrophotometrically according to Arnon2 measuring optical absorbance at 645 and 663 nm. 

Fig. 6 SeaWiFS image for July 13, 1998. Dark color corresponds to the waters with a high chlorophyll concentration...

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