Elham Kolahian Hamedanizad; Hosseinali Ramshini; Mohammad Ghader Ghaderi; Mehdi Fazel Najafabadi
Abstract
In Iran where main part of precipitation takes place during winter and spring, wheat is dependent on water conserved in the sub soil especially at dryland farming systems. In order to identify the genotypes with suitable root system development at sub soil depths, an experiment was conducted with 63 ...
Read More
In Iran where main part of precipitation takes place during winter and spring, wheat is dependent on water conserved in the sub soil especially at dryland farming systems. In order to identify the genotypes with suitable root system development at sub soil depths, an experiment was conducted with 63 bread wheat genotypes planted in PVC tubes under non stress and drought stress conditions. Under non-stress condition irrigation was conducted regularly, while under stress condition it was delayed until soil moisture was depleted to 30 percent of field capacity. After applying stress and at the end of growth season, root related traits in four depths (0-20, 20-40, 40-60 and 60-100 cm) along with morphological traits, yield and its components were measured. The results showed great variations among genotypes for all studied traits. Highly significant correlations were observed between total root weights and yield under stress conditions (r=0.58, p=0.01). Under these conditions, a unit increase in root dry weight resulted in a 0.24 g increase in grain yield of each plant. Separate correlation analysis for each depth showed that the effect of root dry weight on yield at the deepest depth was higher than other profiles (r=0.75, p=0.01). Under stress conditions, the effect of root weight on yield at 60-100 cm depth was positive and highly significant. Genotypes of Sardari, Sholeh, Naz and Inia were the best genotypes considering root dry weight at this profile with 0.44, 0.39, 0.37 and 0.37 g.plant-1, respectively.
Ahmad Jafarnezhad; Hosein Aghaie
Abstract
In order to study the genetic variation, identification and selection among wheat genotypes based on quantitative indices of drought stress tolerance, this experiment was conducted with 16 bread wheat genotypes arranged as a randomized complete block design with three replications under normal and restricted ...
Read More
In order to study the genetic variation, identification and selection among wheat genotypes based on quantitative indices of drought stress tolerance, this experiment was conducted with 16 bread wheat genotypes arranged as a randomized complete block design with three replications under normal and restricted irrigation regimes at the Neishabour Agricultural and Natural Resources Research Station during 2008-09 cropping season. Used indices were Mean Productivity (MP), Geometric Mean Productivity (GMP), Harmonic Mean (HMP), Stress Tolerance Index (STI), Stress Susceptibility Index (SSI), Tolerance Index (TOL) and Lin and Binns Sustainability index (Pi). Results showed that the highest grain yield under stressed environment and the greatest values of MP, GMP, HARM, STI and Pi were obtained in genotype no. 2. Analysis of correlation and mean grain yield under restricted and normal irrigation conditions showed that these five indices were suitable for screening genotypes. According to these indices and grain yield under these two environments, the best drought tolerant genotypes were no. 2, 11 and 14. Multivariate biplot diagram showed that genotypes no. 2, 11 and 14 were adjacent to drought tolerance indices i.e. MP, GMP, HARM, and STI. Cluster analysis results also revealed that genotypes no. 2, 11 and 14 were drought tolerant and genotypes no. 3, 8, 9 and 13 were drought susceptible lines.
Amin Hayati; Mahmood Ramroudi
Abstract
In order to investigate the time of potassium application and irrigation regimes effects on agronomic traits, yield and seed quality of foxtail millet, a field experiment was conducted as split plot based on randomized complete block design with three replications at Agricultural Research Center of Yasuj, ...
Read More
In order to investigate the time of potassium application and irrigation regimes effects on agronomic traits, yield and seed quality of foxtail millet, a field experiment was conducted as split plot based on randomized complete block design with three replications at Agricultural Research Center of Yasuj, Iran, during 2009. The irrigation regimes including 7, 14 and 21 day intervals were considered as main plots and sub-plots included potassium fertilizer application at four stages of planting, tillering, stem development and flowering. The results showed that the effect of irrigation regimes was statistically significant on plant height, leaf number, ear size, grain yield, leaf chlorophyll content, water soluble carbohydrate and protein percentage. Increasing the irrigation period, decreased all of the above mentioned traits except protein percentage which was enhanced by increasing the irrigation period. Also the time of potassium application significantly affected plant height, grain yield, leaf chlorophyll content, water soluble carbohydrate and protein percentage, so that potassium application until flowering stage increased the studied traits. The interaction effects of irrigation and potassium application on plant height, seed yield, leaf chlorophyll and soluble carbohydrates was significant. The maximum seed yield was obtained by using potassium at the stem development stage and 7- day irrigation regime, and the maximum seed protein percentage was obtained in 21- day irrigation regime and potassium application at flowering stage.
Hamid Jabbari; Gholam Abbas Akbari; Nayer Azam Khosh Kholgh Sima; Amir Hosein Shirani Rad; Iraj Alahdadi; Faezeh Tajodini
Abstract
In order to study the agronomic, physiologic and qualitative characteristics of canola (Brassica napus L.) under irrigation stress, an experiment was carried out as a randomized complete block design with three replications at the Research Field of Shahr-e- Qods Branch, Islamic Azad University, in 2010-2011 ...
Read More
In order to study the agronomic, physiologic and qualitative characteristics of canola (Brassica napus L.) under irrigation stress, an experiment was carried out as a randomized complete block design with three replications at the Research Field of Shahr-e- Qods Branch, Islamic Azad University, in 2010-2011 cropping season. In this experiment, the irrigation treatment had three levels including optimum irrigation over the growing period based on 80 mm evaporation from class A evaporation pan (control), irrigation cessation from flowering to physiological maturity, and irrigation cessation from silique formation until physiological maturity. The results indicated that the effect of irrigation treatment on plant height, stem diameter, branches per plant, relative water content (RWC), water saturation deficiency (WSD), Chl a and carotenoids, silique length, siliques per plant, 1000- seed weight, seed yield, seed oil content, oil yield, harvest index and productivity effort were significant. Irrigation cease from flowering and silique formation onwards decreased the RWC by 43.1 and 29.5%, Chl a by 32.7 and 26.5%, and carotenoid by 49.6 and 31.8% compared to normal irrigation (control treatment), respectively. In this study, normal irrigation (control) showed the greatest seed yield and seed yield was reduced from 2577 kg.ha-1 at control to 1483 and 1907 kg.ha-1 in irrigation cessation from flowering and silique formation onwards, respectively. Positive correlations were observed between seed yield and yield components, except seed number per silique and the greatest correlation occurred between seed yield and 1000- seed weight and silique per plant, respectively. Overall, these results showed that irrigation cessation from flowering until physiological maturity had more adverse impacts on physiological and morphological characteristics, seed yield and related traits compared to irrigation cease from silique formation to physiological maturity.
Habiballah Nadian; Siroos Jafari; Behzad Nateghzadeh
Abstract
In a greenhouse experiment, the effect of four salinity levels (1, 2, 4 and 8 dS m-1) and three levels of urea fertilizer (200, 300 and 400 kg urea ha-1) on growth parameters, cane juice ionic composition and uptake of some nutrients by sugarcane variety CP69-1062 was studied. The study was done as a ...
Read More
In a greenhouse experiment, the effect of four salinity levels (1, 2, 4 and 8 dS m-1) and three levels of urea fertilizer (200, 300 and 400 kg urea ha-1) on growth parameters, cane juice ionic composition and uptake of some nutrients by sugarcane variety CP69-1062 was studied. The study was done as a factorial experiment based on randomized complete block design with three replications. The results showed that increasing salinity from 1 to 8 dS m-1 remarkably reduced the length and dry weight of root and consequently shoot dry weight including weight and number of cane and plant biomass per pot. The highest root dry weight and total root length were observed in salinity of 1 dS m-1 and application of 400 kg urea ha-1, and the lowest amount of these traits were observed in the treatment of 200 kg urea ha-1 and salinity of 8 dS m-1. Na concentration in plants subjected to salinity stress was reduced as urea fertilizer was increased, while K uptake was increased and this led to an increase in K:Na ratio in both leaf and cane juice, more proline accumulation and finally increased cane weight. Electrical conductivity, ash and Na concentration in cane juice were significantly increased by increasing salinity. The results of this study confirm the hypothesis that detrimental effect of salinity on plant can be reduced by enough N fertilizer application.
Meysam Ghaedi Jashni; S. Mohsen Mosavinik
Abstract
Drought is one of the most important limiting factors of plants growth which limits about 25 percent of arable lands production over the world. To investigate the effect of drought stress and phosphorus and zinc fertilizer levels on the quantitative properties and essential oil content of German chamomile ...
Read More
Drought is one of the most important limiting factors of plants growth which limits about 25 percent of arable lands production over the world. To investigate the effect of drought stress and phosphorus and zinc fertilizer levels on the quantitative properties and essential oil content of German chamomile (Matricaria recutita cv. Gural), a split plot factorial experiment was conducted in a randomized complete block design with three replications at Research Farm of University of Zabol in 2013. Treatments consisted of three irrigation 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 ZnSO4(H2O) levels (0 and 30 kg ha-1) as sub plots. Some traits such as plant height, number of flowers per plant, flower diameter, fresh and dry flower yield, root length and essence yield were measured. The results showed that drought stress significantly reduced values for all morphological traits, except root length. However, no significant mild stress effect was observed for essential oil content. The application of 150 kg P fertilizer ha-1 and 30 kg Zn fertilizer ha-1 increased essential oil content and values for morphological traits. The application of high amount of P fertilizer (300 kg ha-1) had negative effects on chamomile yield. In general, the results of this experiment showed that the application of 150 kg P fertilizer ha-1 and 30 kg Zn fertilizer ha-1 under mild stress (50% of field capacity) can improve essential oil content in German chamomile.
Fatemeh Baniasadi; Vahid Reza Saffari; Ali Akbar Maghsoudi moud
Abstract
This study was carried out to investigate the effects of salinity and putrescine on pot marigold at four salinity levels applied by sodium chloride with electrical conductivities (EC) adjusted at 1, 3, 6 and 9 dS/m and putrescine sprayed at 0, 1 and 2 mmol in a factorial experiment based on completely ...
Read More
This study was carried out to investigate the effects of salinity and putrescine on pot marigold at four salinity levels applied by sodium chloride with electrical conductivities (EC) adjusted at 1, 3, 6 and 9 dS/m and putrescine sprayed at 0, 1 and 2 mmol in a factorial experiment based on completely randomized design (CRD) with three replications in greenhouse conditions. Traits studied were average stomatal length on abaxial and adaxial sides of leaf, relative water content, chlorophyll index, minimum and maximum florescence (F0 and Fm respectively) and photosystem II quantum yield (Fv /Fm). ANOVA results showed that salinity stress had significant effects on all mentioned characteristics, so that all characteristics were reduced by increasing salinity levels except F0 and Fm. Salinity reduced chlorophyll index, quantum yield and average stomatal length on both leaf sides up to 30%, 27.3%, 5%, 23%, 22.5%, respectively. Moreover, putrescine reduced these negative effects of salinity on some parameters such as chlorophyll index and quantum yield. Putrescine also reduced the length of stomata.
Nafiseh Khalili; Behnam Kamkar; Amir Hasan Khodabakhshi
Abstract
Nowadays medicinal plants are considered as economically important plants throughout the world, while basic information on these plants is scarce. This study was aimed to quantify germination rate response of annual savory (Satureja hortensis L.) to temperature and salinity stress. For this purpose, ...
Read More
Nowadays medicinal plants are considered as economically important plants throughout the world, while basic information on these plants is scarce. This study was aimed to quantify germination rate response of annual savory (Satureja hortensis L.) to temperature and salinity stress. For this purpose, seeds were exposed to different temperature (12, 15, 20, 25, 30, and 35 ͦ C) and salinity levels (0, 25, 50, 75, 100, 125 and 150 mM NaCl) treatments at Seed Research Lab., Gorgan University of Agricultural Sciences and Natural Resources in 2013. Results indicated that temperature and salinity stress and their interactions had significant effects on maximum germination percentage (MGR), germination rate (R50), and time elapsed to reach 10, 50 and 90% of maximum germination. Along with salinity levels increment, both germination percentage and rate decreased. With temperature increasing to optimum temperature, both germination percentage and rate increased, while they decreased from optimum temperature onwards. Assessment of three nonlinear regression models including segmented, dent-like and beta models revealed that the last one was the superior model. Based on the superior model (Beta), base, the optimum and ceiling temperatures were estimated as 8, 24.77 and 41 ͦ C, respectively. Biological hours for control treatment (zero salinity level) were calculated as 83.68 hours. Optimum and ceiling temperatures were not affected by salinity stress, but the base temperature and biological hours for germination was delayed as 1.35 ͦC decrement and 1.65 hours increment per each 25 mM salinity levels.
Azadeh Haddad Sabzevar; Mahboobeh Nakhaei Moghaddam; Mohammad Reza Zolfaghari
Abstract
Rhizobia are well known group of symbiotic bacteria that infect roots of leguminous plants and fix nitrogen. These are facing multiple stresses in the soil that influence growth of bacteria, establishing symbiosis and nitrogen fixation ability. This study aimed to evaluate the tolerance of twenty three ...
Read More
Rhizobia are well known group of symbiotic bacteria that infect roots of leguminous plants and fix nitrogen. These are facing multiple stresses in the soil that influence growth of bacteria, establishing symbiosis and nitrogen fixation ability. This study aimed to evaluate the tolerance of twenty three isolates of Sinorhizobium meliloti to heavy metals, antibiotics and different concentrations of salinity in Mashhad and Sabzevar. Resistance of isolates to antibiotics was determined by agar diffusion method for penicillin, tetracycline, vancomycin, nalidixic acid. Bacterial resistance to heavy metals, including copper, cadmium, zinc, manganese and various concentrations of sodium chloride, 0.5, 1, 2, 3, and 4% in solid medium was tested. The results showed that 100% of the isolates were resistant to penicillin and susceptible to tetracycline. Inhibitory pattern was different for vancomycin, nalidixic acid, and streptomycin. The isolates were grown at concentrations of 0.5 mmol CuCl2, 0.65 mmol CdCl2, 0.125 mmol ZnSO4 and 1.5 mmol MnSO4. Results of tolerance to different levels of salinity showed that all isolates had the ability to grow in low concentration of NaCl and only seven isolates had the ability to grow in high concentrations.
Mehdi Mojab; Mojtaba Hosseini; Gholam Reza Zamani; Ardeshir Kohansal; Esmaeil Ebrahimi
Abstract
Seed dormancy is one of the major obstacles against evaluating the effect of different environmental factors on germination characteristics of weed seeds. In order to realize the type of Mesquite seed dormancy, an experiment was conducted based on completely randomized design (CRD) with twelve treatments ...
Read More
Seed dormancy is one of the major obstacles against evaluating the effect of different environmental factors on germination characteristics of weed seeds. In order to realize the type of Mesquite seed dormancy, an experiment was conducted based on completely randomized design (CRD) with twelve treatments and four replications. Treatments were six different times of seed soaking in sulfuric acid 95-98% (10, 20, 30 40, 50 and 60 minutes), mechanical scarification with sandpaper for 5 minutes, seed soaking in distilled water for 24 and 48 hours and soaking seeds in boiling water (95-98 °C) for 5 and 10 minutes as well as a control treatment. Results showed that all chemical and mechanical scarification treatments resulted in mesquite germination and the highestgermination rate, root and stem length, and root and stem fresh weight were observed in the treatment of seed soaking in sulfuric acid for 60 minutes. Moreover, in order to study the effect of salinity and drought stress on germination characteristic of mesquite, two separate experiments were conducted as completely randomized design (CRD) with four replications. Treatments included different osmotic and matric potentials at four levels (-0.3, -5, -10 and -15 bars) as well as a control treatment (0 (distilled water). Results showed more negative osmotic and matric potentials significantly (p≤ 0.001) decreased the germination percentage and rate in comparison with the control, and this reduction was greater with the drought stress. The parameter X50 of the three-parameter logistic model showed that the 50% reduction in maximum germination percentage of mesquite occurred at -16.23 and -6.26 bar of osmotic and matric potentials, respectively, which indicated a greater sensitivity of this species to drought stress.
Maryam Janalizadeh Ghazvini; Ahmad Nezami; Ebrahim Izadi-Darbandi; Mehdi Parsa
Abstract
In order to evaluate the cold tolerance of Lancelot Plantain plant, a Factorial experiment based on completely randomized design was conducted with three replications under controlled conditions at Faculty of Agriculture, Ferdowsi University of Mashhad. Experimental factors included plantain ecotypes ...
Read More
In order to evaluate the cold tolerance of Lancelot Plantain plant, a Factorial experiment based on completely randomized design was conducted with three replications under controlled conditions at Faculty of Agriculture, Ferdowsi University of Mashhad. Experimental factors included plantain ecotypes (Bojnord, Kalat, Mashhad, Ghayen and Birjand) and freezing temperatures (0, -3, -6, -9, -12, -15, -18 and -21°C). To apply freezing temperatures, Plantain plants were transferred to a Thermo gradient freezer on January 20, 2012, after 3 months growth and hardening under natural environment. In order to assess the plasma membrane stability, electrolyte leakage percentage (EL %) and the lethal temperature required for 50% of plants according to the EL% (LT50el) was determined. Plant survival assessed four weeks after freezing treatment by measuring survival percentage and the lethal temperature required for 50% of plants according to the survival% (LT50su). Results showed that in terms of LT50el, the Mashhad ecotype was the most tolerant and Kalat and Birjand ecotypes were the most sensitive ones. Ecotype and temperature interactions had noticeable effects on EL and Survival percentage, so that Bojnord and Birjand ecotypes had the least and the most EL% at -12 °C, respectively. At the same treatment, Mashhad ecotype with 94.4 % and Birjand ecotype with 25.4% exhibited the most and the least survival percentage. The value of LT50su forMashhad ecotype was 5.3°C lower than Birjand ecotype. There was high and negative correlations between EL% and survival percentage (r=-0.70**) in this survey. Moreover, there was significant and positive correlations between LT50el and LT50su (r= 0.53*). According to these findings, Mashhad and Bojnord ecotypes exhibited greater freeze tolerance than Birjand ecotype.
Seyed Ali Tabatabaei; Ehsan Shakeri
Abstract
In order to study the effect of drought stress based on irrigation intervals (7 and 10 days) on grain yield of four maize single cross hybrids (500, 647,700 and 704), a split plot experiment was conducted based on randomized complete block design with 3 replications at Khatam county during the summer ...
Read More
In order to study the effect of drought stress based on irrigation intervals (7 and 10 days) on grain yield of four maize single cross hybrids (500, 647,700 and 704), a split plot experiment was conducted based on randomized complete block design with 3 replications at Khatam county during the summer of 2009. Plant height, number of row in ear, number of grains in row, number of grains in ear, ear length, ear diameter, ear wood weight, 1000- grain weight, biological yield, grain yield and harvest index were measured. The results showed that drought stress caused a significant decrease in all measured traits, so that the grain yield was reduced from 10.2 to 5.5 ton/ha by increasing the irrigation interval from 7 to 10 days. There were also significant differences between hybrids grain yield. The greatest grain yield was produced by KSC704 under non-stressed conditions (11.2 ton.ha-1) and the lowest grain yield was produced by KSC500 under stressed conditions (3.9 ton.ha-1). The MP, GMP, STI indices introduced the SC704 as the most resistant hybrid, while TOL and SSI indices indicated the SC704 and SC700 as the most resistant hybrids, respectively.
Navid Vahdati Mashhadian; Ali Tehranifar; Yahya Selahvarzi; Atefeh Tabasi
Abstract
The aim of this study was to find out the effects of salinity stress along with salicylic and ascorbic acid priming (as alleviators) on seed germination of Trifolium repens and Trifolium pratense (native) and Trifolium pratense cv. Marino using a factorial experiment based on completely randomized design ...
Read More
The aim of this study was to find out the effects of salinity stress along with salicylic and ascorbic acid priming (as alleviators) on seed germination of Trifolium repens and Trifolium pratense (native) and Trifolium pratense cv. Marino using a factorial experiment based on completely randomized design with 4 levels of salinity stress (0, 100, 150 and 200 mM) and 5 levels of alleviators (0, 100 and 200 ppm of each) with 3 replicates. Results showed that salinity stress, interaction between salinity and alleviator and 3 way interactions had significant effects on measured traits (P≤0.01). The greatest and lowest values measured for different traits in this experiment were observed in the control and high salinity treatments, respectively. Germination percentage at the highest levels of salinity (200 mM) in T. repens, T. pratense (native) and T. pratense cv. Marino were reduced by 90, 77 and 78% compared to the control, respectively. Applying ascorbic acid (200 ppm) at the same level of salinity improved germination percentage by 88, 71 and 70%, respectively. Similar results were obtained for germination rate. In general, although salinity stress disrupts germination, it is possible to improve germination percentage and rate of clover seeds under salinity stress through using alleviators.
