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Aims: The aim of this study was to investigate the effect of Diuron in vitro on the growth rate of Anabaena flos-aquae in order to determine the toxicity of diuron by calculating EC10, EC50, EC90, and MAC value for this alga to control flourishing in this phytoplankton.
In this experimental research, the growth rate of Anabaena flos-aquae was investigated under the influence of diuron. This experiment was conducted in 96 days with 6 treatments (0.0005, 0.009, 0.016, 0.03, 0.054, and 0.01 mg/l), 1 control group, and 3 repetitions of the treatments in 500cc Erlenmeyer flasks. The growth rate was measured, using cell counting, turbidimetric measurement, and chlorophyll a measurement methods. Then, achieved quantities of EC were used in four 500cc Erlenmeyer flasks and the concentration of algae was evaluated through cell counting in 24-hours periods during 96 hours. Using SPSS 17 software, one-way ANOVA was used to compare the increase percentages between different treatments.
Findings: Quantities of EC10, EC50, EC90, and Mac value of this toxicant for the algae according to chlorophyll a concentration were reported 0.006, 0.01, 0.05, and 0.001 mg/l, respectively. The frequency of Anabaena flos-aquae was significantly different in presence of concentrations obtained from EC indices and decreased sharply in EC90 quantities.
The use of diuron in the proposed concentrations reduces its risk from the perspective of toxicity and contamination of other components of the ecosystem and it is more effective in this group of algae.

Effects of Gillard media and 4 salinities (15, 20, 25 akd 30ppt) on growth parameter of chlorella vulgaris were surveyed using a completely randomized design. Expriments lasted 12 days. All treatments had three replication. Acording to the results the highest density of chlorella vulgaris with 125.30 × 106 cells/ml ± 0.41 × 106 cells/ml was observed in the treatment with salinity of 20ppt which was significantly different from the others ( P<0.05). the minimum density of chlorella vulgaris with 101.62 × 106 cells/ml ± 1.54× 106 cells/ml was observed in salinity of 30 ppt. The maximum specific growth rate of 1.92 ± 0.08 was observed in salinity of 20ppt on day2 and the minimum growth rate of 0.08 ± 0.02 was observed in salinity of 15ppt during days 6-8 . Acording to the results, Gilard medium under salinity of 20 of ppt is suitable for cultivating of chlorella vulgaris in laboratory.

Cell concentrations and growth rate of Dunaliella salina Teodoresco in light intensities of 50 and 150 μmol. photons.m-2.s-1 and temperatures 25 ± 0.5 and 31 ± 0.5 oC (mean ± SD) were studied. The algae was isolated from the Urumieh Lake and cultured in various treatments (n = 12). Algae cells were counted regularly using Thoma counting chamber in 3 replicates on daily basis. The curve of changes in population was plotted. The highest cell concentration (mean ± SD) of 4.8 ± 0.6 × 10 6 cell.ml-1 was observed in light intensity of 150 μmol. photons.m-2.s-1 and temperature 25 ±0.5 oC. The minimum cell concentration (2.8 ± 0.3 × 10 6 cell.ml-1) was observed in light intensity of 50 μmol. photons.m-2.s-1 and temperature 31 ± 0.5 oC. The maximum growth rate (0.38 d-1) was recorded in light intensity of 150 μmol.photon.m-2.s-1 and temperature 25 ± 0.5 oC and the minimum (0.16 d-1) in 50 μmol.photon.m-2.s-1 at temperature 31 ± 0.5 oC Increase in temperature from 25 to 31 oC was found to be correlated with decrease in cell concentration and growth rate in D. salina., but increase in light intensities from 50 to 150 μmol. photons.m-2.s-1 resulted in increase of these factors.

This study provides information on the effect of three light intensities (37.5, 62.5 and lOO!lmol photons.m- 2 s-1) and photoperiods (light:dark) cycle 8:16, 12:12 and 16:8h on growth rate, duplication time and biomass production in microalga Chiarella vulgaris. Stock of C. vulgaris was separated from water samples taken at Anzali Wetland, purified and cultured in lOOOml Erlenmeyer at constant temperature 25±0.5°C, using Zehnder medium.Cell count was conducted daily and biomass was measured at the exponential growth phase in different treatments. Analysis of variance indicated significant difference (P<0.05) among light regimes. The maximum growth rate 1.13d-1 was observed at 10011mol photons.m- 2 s-1 and 16:8h light duration and also the minimum duplication time 0.61d- 1 occurred at this treatment. The maximum biomass 2.05gr 1 was recorded at 62.5!lmol photons.m -2 s-1 and 8:16h light period.