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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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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.

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The effects of plant growth promoting rhizobacteria (PGPR) on growth and physiological characteristics of seedlings Corylus avellana were determined in a forest nursery. For this purpose, in a completely randomized design (CRD) and four replicates, three putative bacteria, including Pseudomonas putida, Bacillus subtilis and Enterobacter cloacae, as alone and mixed, were examined. The greatest height (26.88 cm), collar diameter (7.11 mm), leaf area (23.87 cm²)net photosynthesis (17.23μmol CO₂ m⁻²s⁻¹), transpiration rate (3.22 mmol H₂O m⁻²s⁻¹­(, stomatal conductance (0.189 mol CO₂ m⁻²s⁻¹), water use efficiency (5.33 μmol CO₂ mmol⁻¹  H₂O) and chlorophyll content (26.16 SPAD) allocated to seedlings inoculated with a combination of three bacteria. The greatest root dry weight (3.98 g), root volume (10.87 cm³), total plant dry weight (9.91g) was detected in seedlings inoculated with P. putida. In total, for the beneficial effects of PGPR on growth and physiological traits of C. avellana seedlings, all three bacteria either as individual or as mixed were found suitable for seedling inoculation. In fact, it is affirmed that inoculation of root with PGPR can be a proper approach to produce healthy and strong seedlings in nursery.

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In the present Study, oil from three major canola varieties grown in Golestan province namely Hyolla401, Hyolla420 and RGS003, have been extracted and stored for four months in dark at room temperature. Oil samples were tested every week for, free fatty acid, acid value, peroxide value, anisidine value, totex value and rancimat test. The results showed  that in all three varieties, free fatty acids, acid value, peroxide value, anisidine value and totex value were increased significantly during storage (α = 0.05). Most changes in free fatty acids, acid value, peroxide value, anisidine value and totex value were observed in Hyolla 420 variety and the least were founded in RGS003 variety. The results of rancimat test showed significant decrease in canola oil stability during storage in all three varieties. The highest oil stability was observed in Hayolla 420 variety. Hyolla 420 variety had the highest level of iron that led to significant decrease in its stability. Chlorophyll is one of the most important factors in oil stability that act as antioxidant in dark condition. The lowest level of chlorophyll were determined in Hyolla4 20 variety that  was in accordance with its low stability.  

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Aims: The increasing development of microalgae applications has led to the concentration of new multidisciplinary studies to facilitate commercial cultivation of these organisms due to cost reduction and productivity enhancement. The aim of this study was the growth and quality optimization of Spirulina biomass by changing the dilution of medium and using the aeration cycle.
Materials and Methods: In this experimental study, the effect of concentration of Zarrouk medium (0 to 100% dilution) and aeration cycle on specific growth rate and dry weight, as well as the content of chlorophyll and carotenoids of Spirulina were investigated, using response surface method, central design. A total duration of 16 hours was aerated in any 24-hour period; the interval time between these aerated periods varied between 1 to 8 hours. The data were analyzed by SPSS 16 software, using multiple regression test.
Findings: The highest biomass (0.659mg/ml) was obtained at 80% concentration of culture media and aeration cycle of 2.75 hours and the highest specific growth rate (0.230 daily) was obtained at 60% concentration and aeration cycle of 4.5 hours. The highest aeration cycle (8 hours) resulted in a significant and simultaneous increase in the content of chlorophyll and carotenoids (11.65 and 2.67 mg/g, respectively).
Conclusion: The growth and quality optimization of Spirulina biomass can be accomplished by changing the dilution of the medium and using the aeration cycle.

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Primary production is a key indicator in the evalution of aquatic ecosystems that can directly affect carbon sequestration. Due to climate change and environmental dynamics, this component has changed spatially and temporally in different ecosystems. Therefore, to understand and monitor these changes, the most important influential parameters include; sea surface temperature, chlorophyll-a and algal bloom on this component and their changes were analyzed based on the time series. Images related to Chl-a, SST and NPP from January 2003 to December 2018 were used by MODIS sensor and VGPM model to estimate NPP in the study area. Aftar pre-processing and extracting the time series algorithm, the trend of variation was determined using the mann-kendall and theil-sen procedure. Then, using enhancing false color composite, algal blooms in the Persian Gulf and the sea of Oman were identified and the amount of chl-a concentration in the algal bloom area and outside the area was determined.  The results of trend analysis with theil-sen procedure showed that the rate of change for chl-a is decreasing in all regions except the fifth region. The highest amount was observed in the fifth region (-0.19), which corresponded to the rate of NPP. The results also show that the highest amount of NPP in the first region in March and the lowest in June and July (540 and 690 gC/m²/day), which corresponds to the amount of chl-a concentration. Despite the apparent correlation, there is no cause-and-effect relationship between SST and chl-a as well as chl-a and NPP. In this way, factors other than chl-a can be considered for algal bloom and NPP.

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Aim: The study was done to determine the effect of humic acid on germination, morphological properties and photosynthesis pigments of Trifolium alexandrium L. under salt stress.
Methods:
This study was conducted in a factorial experiment in a completely randomized design (using analysis of variance). The first factor was humic acid (0,0.009mgLi⁻¹). The second factor was salt stress (0,0.75,1.5,3dSm⁻¹). Seed germination, vigor index, allometric coefficient, radicle and pedicle length, total dry and fresh weight, and photosynthetic contents were measured.
Findings: The minimum and maximum germination rate (4.00 and 4.90seed/day) and vigor index (1.79 and 6.33) were related to 3dSm^-1 and H+3dSm^-1 treatments, respectively. The germination percentage did not show significant difference (p<0.05). The radicle and pedicle lengths, allometric coefficient, germination rate and vigor index in the zero treatment were more than the H treatment but they decreased with increasing salinity. The minimum and maximum radicle (0.79 and 2.30cm), pedicle lengths (0.79 and 2.55cm) and dry weight (0.0014 and 0.0026g) were related to the 3dSm^-1 and H+3dSm^-1 treatments, respectively. The highest chlorophyll a (0.31 mg g^-1 fresh weight), carotenoid (0.07 mg g^-1 fresh weight) and total chlorophyll (0.48mgg^-1 fresh weight) were related to H+1.5dSm^-1. The highest amount of chlorophyll b (0.34mg g^-1 fresh weight) was observed in H+3dSm^-1.
Conclusion: Humic acid had different but positive effects on quantitative properties and germination characteristics of the plant in salinity stress. The use of this fertilizer in salinity stress for salinity-sensitive plants can be useful but more comprehensive survey in the field is recommended.

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Aim This investigation aims to study the effect of biochar on gas exchange, water relations and photosynthetic pigments of European yew (Taxus baccata) seedling in different light intensities (LI).
Materials and Methods Two-year potted seedlings of European yew are placed in forest stands with canopies of closed (15% LI), semi-closed (45% LI) and open (75% LI). In late June 2018, biochar was added to potted soils at the levels of zero, 10, 20 and 30 g.kg^-1 and until the end of November, every 3 (or 4) days 100 mL water was given to each pot.
Findings Seedling survival at different levels of treatments was 100%. Regardless of biochar, the highest photosynthesis, stomatal conductance, intercellular CO₂ concentration, relative water content, chlorophyll (chl) contents in closed canopy, and the highest leaf temperature in open canopy was observed. With increasing biochar concentration, chl b and total chl increased (28-86%, respectively) in open canopy and decreased (28 and 28%, respectively) in closed canopy. Neither biochar nor LI affected significantly electrolyte leakage and carotenoid content.
Conclusion Although yew seedlings were able to maintain their vegetative quality and health in different LI, and the measured variables responded differently to light-biochar combination, it may be best to grow yew in shade together with biochar. Since, the effect of biochar becomes more tangible over time, further research in next years can lead to more accurate findings affected by the combined light-biochar treatment.

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Abstract:
Aim: With global warming and limited water resources in the world, especially in arid lands of Iran, managing the production of forest seedlings in the country's nurseries is facing a special challenge. In this regard, the study of drought tolerant plants to select them in the mass seedling production programs can be useful.
Material and methods: Potted seedlings of Persian oak (Quercus brantii Lindl.), pistachio (Pistacia atlantica Desf.), Judas-tree (Cercis siliquastrum L.) and black poplar (Populus nigra L.) exposed to a normal irrigation scheme (100% field capacity) and drought-stressed (30% field capacity) conditions were examined over a period of 120 days in a greenhouse of Bam Khorramabad Nursery to judge their tolerance for drought stress.
Findings: Drought-tressed seedlings from all species had a lower content of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids compared to the control plots, but the content of proline and malondialdehyde (MDA) did, however, increase. Under stress conditions, MDA content in black poplar, Judas-tree, Persian oak and pistachio was 174, 121, 105 and 102% higher than the control seedlings, respectively, and this increase in black poplar over other species ranged from 93.5 to 176.5%.
Conclusion: This study confirms that among four tree species, black poplar has lowest tolerance to drought stress. Thus, Persian oak, pistachio and Judas-tree, should be prioritized in the mass seedling production programs of nurseries in arid areas suffering from limited water resources, due to their higher tolerance to water scarcity.

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Chlorophyll fluorescence was studied as a rapid technique to detect weight loss of table grape cultivars "Thompson and Flame seedless" under air storage conditions (20°C) and in a 0ºC cold room. Grape clumps (ca. 1kg) were divided into 12 groups (six for each cul-tivar) and initial fresh weight, soluble solid content, titratable acidity, pH and color values were recorded. Three groups were placed inside ventilated baskets with a HarvestWatch sensor facing down on the grapes and placed in a 20ºC room in front of a forced air fan. These samples were used to generate continuous recording of F-α. The other groups were handled in a similar manner and were used to generate weight loss. The control treat-ments were held in a 0ºC cold room and constantly measured by a HarvestWatch sensor. F-α (F0) ratio curve for Thompson generally declined over times, and the rate of reduction was maximal between days 1 and 6 which is equal to ca. 20 percent in weight loss. The re-sponse for Flame grapes was almost the same as for the Thompson cultivar. There were good relationships between F-α values and weight loss values for both cultivars. From these relationships it appears that, for both cultivars, at about 20% weight loss (equal to 0.8 weight loss ratio), the F-α value stopped its decline. The other fruit quality such as SSC, TA, pH and color value indicated that the drying treatment affected these responses, compared with the fruit in the control treatment. Our results indicated that chlorophyll fluorescence techniques can detect weight loss in grapes after harvest, and thus has a po-tential as a rapid and non-destructive method for monitoring fruit weight loss and senes-cence in grape during storage.

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In the present study,sampling was carried out using 7 extra virgin olive oils from  Gillan, Zanjan, Ghazvin, Golestan,Fars and Kermanshah Province. The amounts of the chlorophylls and carotenoidswere determined  for each sample using diol-phase cartridges and the extract was analysed by reverse-phase HPLC.Pheophytina (29/29%)  show the highest content of all pigments in Iranian extra virgin olive oils and pyropheophytin (0/14%) show the lowest concentrations. Lutein (51/48%)  show the highest content of all carotenoids pigments followed by violaxanthin in Iranian olive oils  and betacaroten (0/76%) and anthraanthin show the lowest concentrations. Pheophyting a shows the highest content of all pigments followed by chlorophyll a in Iranian olive oils and pheophytina andpyropheophytin show the lowest concentrations. The correlation between amount of pigments and three environment factors; temperature, raining fall and height were investigated. Statistical studies showedthere is a direct relationship between pyropheophytin content and the hight of sampeling local with a 95% confidence limit.An increase in hight resulted in decrease pigments.And also there is a positive correlation at 95% confidence level between lutein and raining of sampeling local.When raing of sampling local increases, lutein has been increasing as well. Statistical studies showed no correlation between temperature and amount of pigmens in the olive oils.

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Aim: Caspian locust, native to Hyrcanian forests of Iran, is one of the pioneer species, which it distributed in the moist soils of these forests. So far, the response of its seedlings to permanent and temporary flooded beds has not been reported. This study was conducted with the objective to analyze the physiological responses of Caspian locust seedlings to flooding and flooding-recovery conditions.

Materials & Methods: Flooding conditions were examined for 90 days in the greenhouse of the Tarbiat Modares University. The study was carried out in a factorial experiment as a completely randomized design with 5 treatments and 4 replications. Treatments included: (1) continuous flooding for 90 days (F90), (2) flooding for 60 days followed by a 30-day recovery (F60+R30), (3) flooding for 45 days followed by a 45-day recovery (F45+R45), (4) flooding for 30 days followed by a 60-day recovery (F30+R60) and (5) Control.
Findings: Results showed that flooding for 90 days induced a significant decrease in net photosynthesis (-91%), stomatal conductance (-77%), transpiration (-81%), Chl a (-63%), Chl b (-67%) and Chl _Tot (-64%) compared to the control (p<0.05). When flooding was removed for 30-60 days, plants were able to recover gas exchange activities from 30 to 90% and Chl content by 55-90%.
Conclusion: Based on our results, seedlings of G. caspica can survive and grow throughout a medium period of soil waterlogging. Therefore, Caspian locust appears to be a promising species for reforestation programs in the riverine areas and temporarily flooded wetlands.
 

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The DINEOF algorithm is a parameter free technique based on iterative EOF analysis that is used to calculate the missing data in a given satellite data set (without requiring any prior information). In this study, the DINEOF technique has been used to fill the gaps in chlorophyll-a data series in the Persian Gulf and Oman Sea. Level 3 data (4 km spatial resolution) of chlorophyll-a concentration obtained from MODIS sensor (2003- 2020) for the study area were used. In some of the images several gaps were found in different months of the year. Images with gap in the Persian Gulf and Oman Sea were reconstructed by rtsa.gapfill R-package and DINEOF algorithm in R software. The linear regression analysis was performed between the missing and reconstructed data, and also parameters such as RMSE, MSE, MAD and SNR were calculated to evaluate the validity and performance of the DINEOF algorithm. The maximum number of the gaps in data series were found in July. Hence, the images of July have been examined and reconstructed as the case study. The original maps of chlorophyll-a concentration showed that the maximum number of the gaps were in July 2009 and 2015. Evaluation of the results showed a high accuracy of DINEOF-reconstruction method (e.g. in July 2014, R² = 0.83, RSME = 0.34, MAD = 0.14, MSE = 0.10). The results showed that the implementation of the DINEOF algorithm (in R) to reconstruct the gaps in chlorophyll-a concentration images could serve as a rapid and efficient technique.

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 A greenhouse experiment was conducted to examine the influence of Phelipanche aegyptiaca on vegetative growth, rate of photosynthesis, chlorophyll fluorescence and leaf chlorophyll content of 35 cucumber genotypes. High demand of assimilates by P. aegyptiaca caused significant reductions in shoot and root dry weight, leaf number, leaf area and plant height in all cucumber genotypes. Once plants were infected by P. aegyptiaca, the leaf chlorophyll content, the photosynthesis rate and the maximum quantum yield of PSII chemistry were significantly less than control, thus implying a reduction in carbon assimilation, photosynthesis efficiency and susceptibility of infected plants to photoinhibition. P. aegyptiaca traits were significantly affected by cucumber genotypes. There was no correlation between P. aegyptiaca traits with the reduction percentage of cucumber shoot dry weight. However, there were correlations between underground attachments number plant^-1 (UAN) and percentage of cucumber root dry weight reduction (-0.58), total attachment number plant ^-1 (TAN) and the percentage of reduction of root dry weight (+0.39). In accordance with the results obtained, the genotypes were classified into 3 groups. It was demonstrated that the genotype number 22 (Khassib) behaved differently to other genotypes and, in particular, they suffered less damage from the presence of P. aegyptiaca.


 

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Intra-specific variation in responses of diurnal and long-term photosynthesis, stomatal conductance, chlorophyll fluorescence, and respiration in spring wheat (Triticum aestivum L.) to salinity was investigated using two tolerant cultivars (CR and Kharchia-65) and a sensitive one (Ghods). Plants were grown in sand culture in controlled environment at selected levels of salinity (5 as control, 100, 200, and 300 mol m-3 NaCl and CaCl2 in 5:1 molar ratios). Photosynthesis was markedly reduced in the saline conditions, but there were no significant differences observed amongst cultivars. Stomatal conductance of both upper and lower leaf surfaces was the main factor limiting photosynthesis in the presence of salinity. However, non-stomatal limitations as indicated by reduction in variable to maximum fluorescence (Fv/Fm) showed that plants might experience some degree of photoinhibition at the highest level of salinity. Gas exchange in control and 100 mol m-3 did not change throughout the day in either the salt-sensitive or the salt tolerant cultivars but in the last hours of the day photosynthesis in the sensitive cultivar was markedly reduced. Respiration remained unchanged up to 200 mol m-3 salinity but at 300 mol m-3 it decreased as compared with the lower salinity levels. The most remarkable change in respiration rate was that at seven hours after light when CO2 production was much higher than at the other times of the day. The results indicated that although photosynthesis is well correlated with stomatal conductance, wheat genotypes show different responses as regards other such aspects of photosynthesis, in different salt concentrations, as growth stage, time of the day and duration of salt exposure.

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