جستجوی مقالات مرتبط با کلیدواژه « carbon dioxide » در نشریات گروه « باغبانی »

 Since the beginning of the industrial revolution, the indiscriminate consumption of fossil fuels has led to a dramatic increase in the concentration of atmospheric carbon dioxide. Over the past few decades, the concentration of atmospheric carbon dioxide has increased from 280 to 370 ppm and is expected to increase by about 1.8 ppm each year. Carbon dioxide, such as light, appropriate temperature, water and nutrients, is one of the essential nutrients needed by plants, which is currently less than required by plants. In general, plants need to absorb water from the soil and carbon dioxide from the atmosphere and use it in photosynthesis, which This is done by absorbing carbon dioxide through the through the pores. In general, stomatal properties have a major influence on the response of plants to carbon dioxide treatment. Leaf  morphology, including stomatal density, may have a significant effect on the response of plants to carbon dioxide. There seems to be a great deal of variation among plant species in terms of how stomata density changes with increasing CO2 concentration. The opening and closing of the stomata through carbon dioxide absorption, regulates the amount of water wasted when adverse environmental conditions. In fact, increasing carbon dioxide in plants reduces stomatal conductance and transpiration, increases water use efficiency, photosynthesis rate and higher light utilization efficiency. 

 This study was conducted as a split plot experiment based on a completely randomized design with three replications in the research greenhouse of Ferdowsi University of Mashhad. Treatments included three concentrations of carbon dioxide (380 ppm as control, 700 and 1050 ppm) as the main plot and two species of ornamental ficus (Benjamin and Elastic) as sub plots. At first, cuttings were rooted in boxes containing washed sand infused with carbendazim for 8 weeks. After rooting, the cuttings were transferred to culture media containing appropriate soil mixture and exposed to different concentrations of carbon dioxide for 16 weeks. Were affected. Mean daily temperature of 25 and mean night temperature of 18 °C and 65% humidity were considered equal for all treatments. Then, after the treatments, Stomatal traits were measured.

 The results showed that high concentrations of carbon dioxide can affect the anatomical traits of Ficus ornamental species. In this study, the results obtained from the analysis of variance of the studied traits showed that the effect of different concentrations of carbon dioxide was not significant only for the stomatal index, but for other traits studied in this study. The main effect of carbon dioxide concentration was significant at 1% probability level.The results showed that the traits of stomata diameter in plant species and different concentrations of carbon dioxide were significant at 5 and 1% probability levels, respectively. Also with increasing the concentration of carbon dioxide the diameter of the stomatal decreased so that the highest stomatal diameter was related to the concentration of 380 ppm and the lowest to the concentration of 1050 ppm. In fact, increasing the concentration of carbon dioxide from the level of 380 to 1050 ppm led to a decrease of 19.91 percent in the diameter of the stomatal. Increasing the concentration of carbon dioxide in the environment of plants, initially increases the slope of the concentration of carbon dioxide between the surrounding air and the chamber under their stomata, and then more carbon dioxide through the pores leads to a decrease in the slope due to the abundance of carbon dioxide in the chamber below the stomata, This action reduces the diameter of the stomatal. As the concentration of carbon dioxide increased the stomatal cell density and stomatal area. Among the high concentrations of carbon dioxide the concentration of 700 ppm affected most of the traits, including stomatal diameter, stomatal area, epidermal cell density, stomach length and stomach width. though there was no significant difference between high concentrations of carbon dioxide (700 and 1050 ppm). According to the results of this study, it seems that anatomical traits are influenced by environmental factors and are not recognized as a hereditary factor. Among the species, the elastica species showed the most reaction to carbon dioxideal. 

 In general, clarifying the stomatal response to carbon dioxide concentration is important for understanding the stomatal physiology and gas exchange between vegetation and the In general, stomatal properties have a major influence on the response of plants to carbon dioxide treatment. Carbon dioxide at appropriate concentrations can increase growth and also affect the stomach properties to allow the plant to adapt to environmental conditions.

To investigate the effect of foliar application of calcium carbonate nanoparticles (CCN) and indirectly increasing carbon dioxide concentration on salt stress modulation of rose 'Dolce Vita., a soilless culture experiment was conducted as a randomized complete blocks design with three replications, in which the pots were filled with a mixture of cocopeat and perlite. The first factor was salinity at two levels (1.8 and 3.2 dS m-1 by adding NaCl to the nutrient solution) and the second factor was foliar spraying of CCN at four levels (0, 3, 6 and 9 g L-1 by using Lithovit fertilizer). Increasing salinity and the concentration of CCN had no effect on potassium and sodium contents of leaves and electrolyte leakage of leaf cells. The salinity of 3.2 dS m-1 reduced the relative humidity of leaf and increased the dry matter percentage and soluble sugar content in the plant leaves; however, had no significant effect on studied morphological characteristics. The application of CCN significantly increased the relative humidity of leaves in both saline and non-saline treatments and the mean of morphological traits (leaf area, flower diameter, stem length and flower yield). In addition, the application of 6 and 9 g L-1 CCN significantly increased the concentration of chlorophyll, carotenoid, and leaf soluble sugar; however, salinity had no effect on these characteristics. Results showed that foliar application of CCN, by affecting physiological and morphological traits and improving plant nutrition, modulates salinity stress and improves the growth conditions of Dolce Vita rose.

In one side the negative effects of increasing of concentration of carbon dioxide in the world، and in the other side، the positive effects of greenhouse enrichment by such gas is one of the most important reasons in researching of this gas on different plants. For assessment of the effects of carbon dioxide and light regimes in different genotypes of Pansy (viola tricolor) a factorial experiment based on completely randomized design with 3 replications and 18 treatments was conducted at the greenhouses of Ferdowsi University of Mashhad at 2009. The treatments are including; 2 concentrations of carbon dioxide (380 and 1000 µmol/mol)، 3 light regimes (11000 and 14000 lux and sun light) and 3 cultivars (Yellow-Black، Bourdeaux، Sawyers-Black) of Pansy. The results of this experiment showed that among the 11 measured traits in the most treatments، the traits of length، width and the number of stomata and dry weight of shoot were significant. The concentration of 1000 µmol/mol carbon dioxide had less decreasing of stomata conductivity and dry weight than carbon dioxide 380 µmol/mol. Totally the effect of light regimes on the measured traits didn’t has any significantly difference with sun light. Among the cultivars، altogether Sawyers was more proper because of less stomata conductivity and probably decreasing of water consumption.

Carbon dioxide (CO2) concentration of the global atmosphere has increased during the last decades. Increasing global atmospheric CO2 concentrations are expected to influence on plants. Coleus is an ornamental plants, that is due to its attractive foliage are considered. In order to evolution of high CO2 concentration effects on rooting. morphological and anatomical traits in two coleus spices (C. scutellarioides and C. blumei) a factorial experiment based on completely randomized design with 3 replications and 6 treatments were conducted at the greenhouses of Ferdowsi University of Mashhad at 2010. Treatments were two coleus spices and 3 concentration, of CO2 380(as a control), 700 and 1050 ppm. Leaf cuttings plants were placed under increasing CO2 concentration during of 30 days. The number of leaves, stem diameter wet weigh, dry weight, length of stoma, width of stoma, size of stoma and stomatal density were measured. Results indicated that increasing CO2 concentration from 380 to 1050 ppm leading to increase of 25.3, 32.4, 20.5 and 75 percentage in number of leaves, stem diameter, wet weigh and dry weight respectively. Also these results showed that with increase of CO2 concentration decreased length of stoma, width of stoma and size of stoma, but increased of stomatal density. The highest mean density of stomatal to 30.7 per mm2, which was related to the interaction of carbon dioxide concentration of 1050 ppm and C. is scutellarioides than other treatments showed significant differences.

To evaluate the effects of various concentration of carbon dioxide and salinity stress on morphophysiological characteristics of Amaranthus tricolor L. an experiment was conducted in greenhouse conditions in Faculity of Agriculture Ferdowsi University of Mashhad. the experiment was split plot based on completely randomized design with three levels of CO2 (380, 700, 1050 μl/L) and three concentrations of sodium chloride (0,150, 300 mM) with 3 replications. The results showed that in control carbone dioxide (380 μl/L), application of salinity to 300 mM, reduced shoot dry weight, plant height and leaf area from 9.34, 53.83 and 1001 to 3.71, 35.3 and 158 respectively. Interaction effects of salinity and carbon dioxide showed that in control salinity and 1050 μl/Lcarbon dioxide, shoot dry weight and plant height increased 46 and 38% respectively. in level of 150 mM sodium chloride, with increasing concentrations of carbon dioxide from 380 to 700 μl/L, leaf area increased from 134 to 358 cm2. at this salinity level, in concentration of 1050 μl/L carbon dioxide, leaf area was 287 cm2. The final results showed that increasing concentrations of carbon dioxide improves adverse effects of salinity. in characteristics such as leaf area and electrolyte leakage, carbon dioxide in 700 μl/L and in characteristics such as root dry weight, shoot dry weight and plant height concentrations of 1050 μl/L carbon dioxide showed a better reaction to salinity.