جستجوی مقالات مرتبط با کلیدواژه « صفات فیزیولوژیک » در نشریات گروه « باغبانی »

Bicarbonate stress causes Fe chlorosis which, in turn, results in yield reduction, the delay in fruit bearing and reduced fruit quality, photosynthesis and growth processes in plants. In this study, the effects of organic acids on the alleviation of bicarbonate stress in some peach cultivars was investigated. The experiment was conducted as a factorial experiment based on a randomized complete block design with 18 treatments and three replications. Factors studied in this experiment included three peach cultivars grafted on GF 677 rootstock, three levels of calcium bicarbonate (0, 7.5 and 15 mM) and two levels of organic acid (0 and 10 mM). Among the studied cultivars, J.H. Hale cultivar was the most sensitive cultivar and Barzegar cultivar was the most resistant to chlorosis induced by iron deficiency. Organic acids significantly improved the growth characteristics of different cultivars, especially under calcium bicarbonate stress conditions. Organic acids reduced the intensity of chlorosis due to iron deficiency in the studied cultivars by up to 20%. In the study of physiological and biochemical traits, it was found that organic acids improve the relative water content of leaves (up to 16%), chlorophyll content (up to 33%), proline accumulation (up to 35.9%) and also increases the activity of antioxidant enzymes including catalase (up to 23.4%), superoxide dismutase (up to 26.5%) and guaiacol peroxidase (up to 14.4%). Organic acids improved the growth characteristics of peach seedlings under bicarbonate stress conditions by improving water relations, leaf chlorophyll and antioxidant enzymes.

In this research, the effect of plant growth-promoting rhizobacteria, Bacillus pumilus, and Zhihengliuella halotolerans, on the morpho-physiological traits of Nitraria schoberi under the influence of dust (control and 1.5 g/m2/month) was investigated. The results showed that dust had a negative effect on the morphological and physiological traits of the plant. Dust caused a decrease of 20, 15, 17 and 20% in chlorophyll a, carotenoid, total soluble protein, and total dry biomass and an increase in the total flavonoids, total phenol content, total antioxidant capacity and glycine betaine amounting to 107, 32, 15 and 10 percents, respectively. Both bacteria improved the condition of the plant against stress, so that B. pumilus and Z. halotolerans increased the amount of chlorophyll b by 13 and 21%, protein by 27 and 43%, and total biomass by 60 and 27%, respectively. In this experiment, the role of B. pumilus strain was more than that of Z. halotolerans strain, so that B. pumilus strain alone had the greatest effect in increasing chlorophyll a and seedling quality index by 52 and 108%, respectively. The results showed that B. pumilus and Z. halotolerans strains can increase the resistance of the Nitraria schoberi to dust stress and help us to stabilize salty dusts in playas.

This experiment was conducted to investigate the plasma treatment effects on seed germination characteristics of Alyssum homalocarpum L. The initial test of plasma on seeds was by atmospheric DBD with a duration of 30 and 15 seconds and 1 to 5 minutes at voltages of 17, 18, 19 and 20 kV, and counting the daily germination of seeds was repeated for 21 days. The seeds were then treated again with atmospheric DBD plasma (30 s and 1 min) at the same voltages and monitored for 21 days. In both times, the changes were observed in the first 3 days, then the seeds were treated with DBD plasma at times of 10, 30 seconds, 1 and 3 minutes. At the end of the initial tests, the seeds were treated in DBD plasma with atmospheric pressure (30 seconds and 1 minute) at voltages of 18 and 20 kV and with DBD corona plasma for 10, 30 seconds, 1 and 3 minutes. Germination rate and percentage, plumule length, radicle length, fresh and dry weight of root and seedling, leaf area and enzyme characteristics were measured. The means comparison results showed that the highest rate (2 seeds per day) and germination percentage (70%) were obtained in the combined treatment of 18 kV and 60 sec. The results showed that the effect of time on dry weight, leaf length, root length and leaf diameter was significant at 1% level. In terms of mean comparison, catalase enzyme and polyphenol oxidase enzyme had a significant difference in the treatments of the combined effect of voltage 20 kV and time 60 seconds and the mutual effect of voltage 18 kV and time 60 seconds. Overall, according to the present findings, the atmospheric DBD plasma and corona plasma pretreatments had a role in improving growth traits and enzymes involved in the biosynthesis of secondary metabolites compared to other treatments without damaging the seeds.

In order to investigate phenotypic and genotypic correlations between physiological characteristics related to drought tolerance and genetic variation and estimating the genetic parameters of these indices in rain-fed condition, 19 genotypes of bread wheat were cultivated in a randomized complete block design with three replications in the research field of Agricultural Research Campus Natural Resources of Razi University of Kermanshah, Iran during 2014-15. analysis of variance (ANOVA) showed significant differences for the grain yield (YS), the cell membrane stability )CMS), the relative water loss )RWL(, the leaf water loss (LWL), the relative water protective (RWP), the water use efficiency )WUE( and the leaf greenish value )LGV( under rain-fed condition. The polygon view of GT biplot showed that genotype no. 12 (wc-4931) was the best genotype compared to other genotypes due to YS, WUE, ELWR and LGV. A high positive genetic and phenotypic relation was observed between WUE and Ys, FV/FM and LWL and, ELWR and LGV. In other hand, High heritability and genetic gain were observed for YS, CMS and WUE that reflect the additive gene action. Accordingly, due to the high propotion of additive effects in CMS, YS and WUE, it was suggested that the evaluation of genotypes must be done at erarly generarion of inbreeding.

Silicon (Si) is the second most abundant element in the earth crust. Silicon has been shown to ameliorate the adverse effects of heavy metals on plants. In order to investigate the effects of silicon nutrition on tolerance of mint (Mentha spicata L.) to cadmium stress, a factorial experiment based on Completely Randomizad Design was conducted in four replications in research greenhouse of Mohaghegh Ardabili University at 2014-2015. Experimental factors included soil contamination by cadmium (0, 50, 100 and 250 mg/kg soil) and silicon nutrition (0 and 1 mM). The number of pots was 32 also in each pot one spearmint stand were planted. During this experiment, traits such as: plant height, plant dry weight, root and stem dry weight, leaf and stem number, leaf area, chlorophylls index, electrolyte leakage, relative water contents, chlorophylls a, chlorophylls b, total chlorophylls, enzyme activity of peroxidase, polyphenoloxidase, as well as proline, carbohydrates, caretenoids were measured. Results indicated the intractive effects of cd stress and si on plant height, leaf area, plant dry weight, stem dry weight, root wet weight, proline, activity of peroxidase, polyphenoloxidase, chlorophylls a, chlorophylls b, were significant. The highest value for carbohydrate, peroxidase, polyphenoloxidase, chlorophylls a, chlorophylls b, plant height, plant and stem dry weight, leaf area, root wet weight were obtained by foliar spraying of 1 mM concentration of silicon and without cd stress. In general, it can be concluded that foliar spraying of silicon is effective to increase total chlorophylls, plant dry weight, and stem dry weight under cd stress.

Climate change has great impact on global production of several major plants. Negative effects of increasing carbon dioxide concentration in the world, on the one hand, and positive effects of the gas on plants, on the other hand, are the most important reasons for investigating the gas effects on different plants. Many studies have been conducted to examine the effects of elevated CO2on plants during the past several decades. Carbon dioxide enrichment in greenhouses can be used as a mechanism for reducing production time, improving quality and increasing plant vigor. The world is facing an increase in the concentration of carbon dioxide in the coming years. The physiological responses of plant are affected by CO2concentration,among which changes in nitrogen, chlorophyll content, proline and soluble sugar have been observed in many studies. The significant changes in the levels of these characteristics are likely to cause marked effects on the entire metabolism of plant. Since the proteins of the Calvin cycle and thylakoid represent the majority of leaf nitrogen, chlorophyll content is the central part of the energy manifestation and can directly determine photosynthetic response and primary production. This study was aimed to investigate the effects of elevated concentration ofCO2 on some morphological and physiological traits of Melia azedarachunder greenhouse conditions. .
The experiment was conducted in a CO2 – controlled glasshouse in a completely randomized design with three replications in Yazd University. The glasshouse consisted of three separate chambers with threeCO2levels of control (450 ppm), 750ppm, and 1100ppm.The concentration of CO2within each chamber was monitored constantly three times a week. After two months, morphological characteristics such as diameter of the collar, height of stem, number of leaves, wet weight of shoots, root wet weight, wet matter biomass, dry weight of shoots, root dry weight, dry matter biomass, and physiological characteristics including proline content of leaves, soluble sugar of leaves, a andb chlorophyll content, total chlorophyll content, carotenoid, nitrogen, phosphorus, potassium and water content of leaves were measured. To analyze the data, normality was assessed using Kolmogorov–Smirnov test. Analysis of variance was performed to detect the difference between the different levels of treatment for all traits. Difference among treatments means were compared by using Duncan test. All the analyses were performed using SAS statistical software.
The results showed that CO2at the concentrations of 750 and 1100 ppm affected significantly all the measured morphological properties except for plant height, root dry weight and physiological traits such as proline, N, and leaves relative water content. However, CO2concentration of 750 ppm had the highest effect on the studied parameters, so that mean dry weight of shoot, dry matter biomass and proline increased up to more than three times, and shoots and roots wet weight and wet matter biomass increased up to more than two times compared to control. The greatest diameter of the collar and the amount of nitrogen were observed at 750 ppm concentration. Concentrations of 750 and 1100 ppm caused a significant increasein the number of leaves (up to two times) and the height of stem compared to control. The increase observed inmorphological characteristics may be owing to photosynthesis stimulation during the experiment in CO2-elevated chamber. Soluble sugar as an important product of photosynthesis increased but the differences were not significant. Soluble sugar may be used for synthesis of morphological characteristics.
Growth of Melia azedarach in elevated-CO2 chamber strongly reacted to theincrease in photosynthesis. Therefore, based on the results of this study,CO2 elevation in glasshouse can be proposed for increasing the growth of plant. Consideringthe continued increaseinCO2 concentrations as a result ofcontinued use of fossil fuels in the word, cultivation of Melia azedarach in urban areas seems an appropriate option. The results of the present study also showed that there is not generally a significant difference between CO2concentrations of 750 and 1100 ppm in Melia azedarach. Therefore, it can be concluded that CO2 up to 750 ppm can cause a significant increase in the growth of this species, because no significant effect was observe between the two concentrations (750 and 1100 ppm) on growth factors.

Heavy metals (HMs) are hazardous environmental pollutants which by entering the food chain cause harm to humans, plants and other organisms. In order to study the effects of salinity and lead (Pb) and cadmium (Cd) HMs on spinach plant, a factorial, pot experiment, based on complete randomized blocks design, was carried out in 2013 in College of Agriculture, Shahrood University of Technology. Treatments consisted of three levels of salinity (0, 4 and 8 dS/m) as factor A and HMs at four levels (control, Cd, Pb and Cd) as Factor B. results revealed that salinity had no significant effect on fresh and dry weight of spinach; but HMs treatment caused significant changes in these traits. Minimum and maximum fresh and dry weights were obtained in the Cd and Cd treatments, respectively. Besides photosynthetic pigments of flavonoids and anthocyanin, salinity had significant effect only on chlorophyll a, chlorophyll b, cartenoid contents and reduced them at 8 dS/m level. Salinity treatment, without affecting potassium content, increased sodium and soluble carbohydrates in spinach leaves. Interaction between salinity and HMs was only significant for carbohydrate, chlorophyll a and chlorophyll b. The highest amount of carbohydrate was obtained in the Cd and 8 dS/m treatment and the highest amount of chlorophyll a and chlorophyll b was obtained in the no salinity (control) and Pb treatment.

The German chamomile (Matricaria recutita L.) is mainly cultivated for essential oil. Nowadays, it is a highly favored and much-used medicinal plant in reqular and traditional medicine. Water deficit is one of the most important limiting factors on crops production in arid and semi-arid regions (Sharafi et al. 2002). Drought stress limits the growth of plants by reducing water content of tissues and causes some metabolic and physiological changes. On the other hand, the availability of nutrients in the soil is affected by drought stress. Thus, nutritional management of plants under drought stress conditions is one of the most important factors in crop production. A better understanding of the role of nutrients in plant resistance to drought is associated with improvement of fertilizer management in arid and semi-arid areas. Our objectives were to investigate the effects of phosphorus and zinc fertilizers on nutrient content and essential oil yield of German chamomile under drought stress.
Material and The experiment was conducted in split plot factorial based on randomized complete block design with three replications at Research farm of University of Zabol in 2013. Drought stress consisted of three levels 75% (control), 50% (mild stress) and 25% of field capacity (severe stress) as main plots, and factorial combinations of three triple superphosphate fertilizer (CaH4P2O8) levels (0, 150, and 300 kg ha-1) and two zinc sulphate fertilizer (ZnSO4H2O) levels (0 and 30 kg ha-1) as sub plots (the fertilizers were applied before planting time). The seeds were sown at 20 cm apart in rows 40 cm wide, on first half of March 2013. Drought stress levels were determined by the Time Domain Reflectometry (TDR). The success of chamomile cultivation as a commercial venture lies in how efficiently and effectively one can collect the flowers at the right stage during the peak flowering season extending over a period of 3–6 weeks. So, flowers were selectively collected on 27 April, 30 April, 4 May, 8 May, and 12 May 2013. German chamomile essential oil was extracted from the dried flowers and using Clevenger system. In the study, the content of potassium, sodium, zinc, phosphorus, chlorophyll a, chlorophyll b and essential oil yield were measured. Statistical analysis was carried out using SAS software (version 9.1). Significant difference was set at P ≤ 0.05 and determined using the Duncan's multiple-range test.
The results showed that exposing chamomile plants to soil moisture stress during its life cycle might lead to a significant effect on essential oil yield and the nutrient content except zinc and phosphorus. The phosphorus fertilizer also affected the content of potassium, sodium, zinc, phosphorus, chlorophyll and essential oil yield while the zinc fertilizer just affected zinc and phosphorus content, chlorophyll b and essential oil yield significantly. Also, we observed that high application of phosphorus fertilizer (300 kg ha-1) had a negative effect on yield of chamomile. This plant growth disorder is maybe because of interaction between P and Zn that is usually termed ‘P-induced-Zn deficiency’. This disorder in plant growth is associated with high levels of available P or with application of P to soil. Thus, it is important that the application of nutrients to be in balance. Having a good nutrient balance is therefore an important factor to improve plant growth by indicating the actual amount and the combination of nutrients that the production needs. Also, this is a good way to save money. In summary, the results of this study indicated that drought stress caused significant effects on physiological traits, essential oil yield and nutrient content. The results showed that optimum amount of Zn and P can improve the studied traits of chamomile. According to the results of this experiment, it seems that the application of Zn under drought stress condition can decrease damage of drought stress that this is maybe because of the critical role of that in plant nutrition and production.
In general, the results suggested that irrigation based on 50% of field capacity with application of 150 kg phosphorus fertilizer ha-1 and 30 kg zinc fertilizer ha-1 can improve essential oil yield and medicine components of German chamomile essential oil.

Using plant growth regulators at the stresses environment can improve plant growth and crop production. Hence، in this research response of photosynthesis rate، chlorophyll، soluble sugar and flower dry weight of chamomile to methyl jasmonate under different salinity levels was studied. Values of 0 (control)، 75، 150، 225 and 300μM methyl jasmonate (MeJA) with salinity levels of 2، 6، 10 and 14 dS/m was evaluated as a factorial experiment based on a randomized complete block design with three replications. The effect of MeJA and salinity was significant for photosynthesis rate، leaf temperature difference (T)، relative water content (RWC)، chlorophyll a، chlorophyll b، total chlorophyll، soluble sugar and flower dry weight. Also، MeJA × salinity interaction affected all traits except T. The highest value of photosynthetic rate (9. 99 µmol CO2 m-2 s-1)، chlorophyll a، b and total chlorophyll، in averaging 5. 98، 41. 18 and 45. 10 mg g-1، respectively، and flower dry weight (3. 73 g pot-1) were obtained at 75μM MeJA and 6 dS/m salinity. But، there was no significant difference between 75μM MeJA×6 dS/m and 75μM MeJA×2dS/m for RWC and flower dry weight traits. Maximum soluble sugar was achieved at 75μM MeJA×14 dS/m treatment. In general، using of MeJA increased RWC and decreased undesirable effects of salinity. With decreasing RWC photosynthetic rate، chlorophyll and flower dry weight decreased، but T increased.

Carbon dioxide (CO2) enrichment in greenhouses could be used for reduction of production time and increasing plant growth and quality. To evaluate the effects of different concentrations of CO2 on growth traits of two ornamental Ficus species (Ficus benjamina and Ficus elastica), a split plot experiment, based on completely randomized design with three replications, was conducted in the greenhouse of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran. Treatments included two species of ornamental Ficus (Ficus benjamina and Ficus elastica) and three concentrations of CO2 (380 (control), 700 and 1050 mg/L). The results showed that with increasing CO2 concentration from 380 mg/L to 1050 mg/L, number of leaves and leaf area were significant at 5% probability level and root/shoot ratio, fresh weight of shoots and plant height were significant at 1% level. Interaction of Ficus species and CO2 concentration was not significant in all traits. In general, increasing CO2 concentration was effective on improvement of physiological and morphological traits of these two ornamental Ficus species.

To find the effects of spring foliar application of Volck® mineral oil and its combination with fertilizer on the physiological، yield and quality characteristics of pistachio fruit، this research was done in the form of a randomized complete block design (RCBD) of 12 treatments and 3 replications on Ohadi pistachio cultivar in Chatrud of Kerman in 2006 and 2007 for a duration of two years. The applied treatments included: T1 (Volck® mineral oil: 0. 2%)، T2 (Volck® mineral oil: 0. 5%)، T3 (Volck® mineral oil: 0. 3 + fertilizer A: 0. 2%)، T4 (Volck® mineral oil: 0. 5% + fertilizer A: 0. 2%)، T5 (Volck® mineral oil: 0. 3% + fertilizer c: 0. 4%)، T6 (Volck® mineral oil: 0. 3% + fertilizer D: 0. 4%)، T7 (Volck® mineral oil: 0. 3% + fertilizer B: 0. 2%)، T8 (fertilizer A:، 0. 2%)، T9 (fertilizer C: 0. 4%)، T10 (fertilizer D: 0. 4%)، T11 (fertilizer D: 0. 2% on the 30th of April)، T12 (fertilizer D: 0. 2% on the 20th of May) and T13 (control). The foliar application in each treatment was done within two times (the 30th of April and 20th of May of 2006 and 2007) with the recommended concentration for each fertilizer on a number of 5 pistachio trees for every treatment. Following the second foliar application، some echophysiological characteristics were assessed. These characteristics included the photosynthetic rate، leaf transpiration temperature، chlorophyll fluorescence، amount of chlorophyll (a، b)، leaf length، and width، number of leaflets، ounce، percent blankness، early splitting as well as cracked nut percentage، weight of 100 nuts، whole product yield، leaf copper، iron، manganese، potassium، zinc and phosphorus contents. The results revealed significant differences among the treatments in most of the measured characteristics at a 5% level of confidence. Also results revealed that application of the applied fertilizer alone improve the qualitative and quantitative trails of the product. Using Volck® mineral oil in 0. 3 and 0. 5% concentration decreased the photosynthesis rate and quality of the product.

In order to investigation effect of drought stress essential oil percent and yield and physiological characteristics of medicinal plant Deracocephalum moldavica L. under greenhouse. This research performed in 2004-2005 at research institute of forests and rangelands. Experiment was carried out in a split plot under randomize complete block design with four replications. Main factors were contains of three populations of Deracocephalum moldavica L. that collected from Tehran, Esfahan and Fars provinces. Subplots were contains three level of drought stress 100% Fc, 60% Fc and 40% Fc. The results showed that effect of different populations not significant. The results showed that effect of drought stress on essence yield, amount of solution carbohydrates, amount of a, b and total chlorophyll at two years were significant. So effect of drought stress on proline in second year was significant. The results analysis variation of two years showed that effect of year on essential oil percent and proline amount was significant (α=1%). Comparison mean of treatments showed that at first year highest of essence yield, solution carbohydrate and chlorophyll respectively related to 60%, 40% and 100% of field capacity treatments. At second year highest proline amount, solution carbohydrate and chlorophyll respectively related to 40%, 40% and 100% of field capacity treatments. Comparison mean treatments of plant populations and different levels of drought stress showed that at first year highest of essential oil percent related to Esfahan seed*60% humidity of field capacity. Highest chlorophyll relate to 100% humidity of field capacity in three ecotypes. At second year highest solution carbohydrate and chlorophyll respectively related to 40% and 100% of field capacity in three populations.