Showing 6 results for Chlorophyll A
Omidvar Farhadian, Seyed Mojtaba Fallahi, Nasrollah Mahboobi Soofiani,
Volume 1, Issue 1 (3-2013)
Abstract
In order to determine effects of chicken and cattle manures in culture of Chlorococcum, an experiment was designed in six treatments including; 0.1, 0.4, 0.8 g/l of chicken manure and 0.1, 0.4, 0.8 g/l of cattle manure as completely randomize design with three replicates for 28 days. Results showed that the mean maximum density (87.1 × 105 cell/ml), specific growth rate (0.054 day-1), algal dry biomass (0.644 g/l), and chlorophyll a (9.42 mg/l) were obtained with 0.8 mg/l chicken manure. In order to compare performance of these manures with other culture media, second experiment with five treatments including; BBM (control) (Bold’s Basal Medium), BBM + soil extract, 0.8 g/l chicken manure, 0.8 g/l cattle manure and mixture of all treatment (BBM, BBM + soil extract, chicken manure and cattle manure) was designed as completely randomize design with three replicates for 15 days. Comparative results showed that BBM + soil extract had highest algal density (11.6 x 106 cells/ml), highest algal dry biomass (0.81 mg/ml), maximum SGR (0.13 /day), highest chlorophyll a (10.15 mg/l) and minimum doubling time (4.97 days). In conclusion, performance of BBM + soil extract was better in terms of biomass and growth parameters of Chlorococcum.
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Volume 3, Issue 3 (12-2014)
Abstract
In a completely randomized design, the effects of heavy metals of Cd, Cu, Pb and Ni at concentrations of 0, 5, 50 and 100 mg/l on chlorophyll a and biomass in green algae Scenedesmus quadricauda were investigated for 14 days under laboratory conditions of 23 °C, 12 h light: 12 hours light and light intensity of 60 mol photons/m2/s. The lowest density, chlorophyll a and dry biomass obtained at 100 mg/l in all of the heavy metals. The mean (±SE) highest increasing rates of chlorophyll a were 24.2±1.1, 23.1±0.8, 36.7±1.4 and 35.5±1.2% for Cd, Cu, Pb and Ni, respectively. Correspondingly, the reduction rates based on dry biomass were 51.5±3.1, 35.2±1.1, 47.9±1.6 and 56.6±2.8% for Cd, Cu, Ni and Pb, respectively. The results showed that heavy metals made significant reduction on chlorophyll a and dry biomass in S. quadricauda.
M. Fallahi Kapourchali , Sh. Rahbary , M. Shamsaei,
Volume 7, Issue 2 (6-2018)
Abstract
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.
Materials and Methods: 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.
Conclusion: 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.
Volume 12, Issue 3 (11-2023)
Abstract
Early blight caused by Alternaria solani is a prominent tomato, Solanum lycopersicum, disease that destroys a significant part of tomato production worldwide. Cultivating resistant cultivars is notably important in reducing damage caused by early blight disease. Therefore, comprehending the response of different genetic backgrounds to pathogen infection could enhance understanding of the mechanisms involved in plant defense systems against pathogen invasion. In the present study, the differential response of susceptible and resistant tomato genotypes to A. solani was investigated from molecular and physiological aspects. The results showed that soluble sugar content in the resistant genotype increased after pathogen inoculation. Although photosynthetic pigments such as carotenoid, chlorophyll a, and chlorophyll b content decreased in susceptible and resistant genotypes, fluorescence chlorophyll indices differed in resistant and susceptible genotypes. Also, transcription analysis revealed that in the resistant genotype, the expression of SlWRKY1 was 2.58 times more than the control at 48 hpi (hours post inoculation). However, in the susceptible genotype, the expression of the SlNAC1 was 69.12 times more than in control at 24 hpi. The findings of this research provide an improved understanding of tomato plant defense mechanisms against early blight disease.
Volume 18, Issue 110 (4-2021)
Abstract
In 2018, the effect of combined treatments of gamma aminobutyric acid with carnuba wax on storage of fresh pistachio cultivar Ahmad Aghaie was investigated using a factorial experiment based on a completely randomized design with three repeats. Factors were edible coatings in five levels including control (distilled water), 10 mM gamma aminobutyric acid (G10), 1% carnoba with 10 mM gamma aminobutyric acid (C1G10), 2% carnoba with 10 mM gamma aminobutyric acid (C2G10) and 3% carnoba with 10 mM gamma aminobutyric acid (C3G10) and the storage time at two levels (25 and 50 days). The results showed that most of the qualitative and quantitative traits such as hull and kernel firmness (4-8% for hull firmness and 7-19% for kernel firmness in different treatments), hull moisture percent (1-2%), total kernel chlorophyll (11-34% in different treatments), aroma (3-30%) and taste (7% decrease in 50th day) showed a descending trend during storage. Kernel carotenoids (5-22%), kernel phenolic compounds (35-44%), kernel flavonoids (8-32%), kernel lipids (31-65%), and antioxidant activity (2-4%) showed an increasing trend. Among the applied treatments, C1G10 seemed to be able to retain most of the qualitative and quantitative characteristics of fresh Ahmad Aghaie pistachio up to 50 days of storage.
Volume 24, Issue 1 (1-2022)
Abstract
To study salinity tolerance of 15 basil accessions widely distributed across Iran, they were grown under two salt levels including control (no NaCl) and 40 mM NaCl (Hoagland nutrient solutions with EC of 1.1 and 5.5 dS m-1, respectively). The studied parameters included morphological characteristics and chlorophyll a fluorescence transient (OJIP) measurements. According to the results, the accessions were categorized into three clusters under the salt stress. Salinity had significant effects on morphological and growth parameters in all basil plants. Compared to the control, NaCl decreased plant height. The number of leaves in Khash, Zabol, and Orumiyeh accessions was more than the others. Both salt and accession caused a decrease up to 43% in leaf fresh weight, emphasizing the major role of accession when salinity was applied. Salinity influenced negatively the biomass yield in basil plants. These decreases varied from 19 to 45% depending on the accessions. Salt treatment of basil plants decreased photosystem II activity, as evaluated from chlorophyll fluorescence data. The parameters that were most affected by salt treatment were maximal quantum yield of PSII photochemistry (FV/FM) and calculated Performance Index (PIABS). Overall, among the studied basil accessions, genotype Ardabil had superior tolerance to salt stress. Furthermore, the most of accessions can be used for studying the mechanism of salinity tolerance in basil plant.
