نشریه فیزیولوژی گیاهان زراعی
پیاپی 35 (پاییز 1396)

In order to investigate the role of calcium and sodium nitroprusside on reducing the destructive effects of salinity stress, this experiment was conducted as split plot-factorial based on a randomized complete blocks design in field conditions. Main factor included two levels of salinity (irrigation with common water and saline water) and sub-factors including sodium nitroprusside at four levels (zero, pretreated seed, foliar application by concentration of 50 micro Molar and pretreated seed foliar application by concentration of 50 micro Molar) and calcium foliar application at three levels (zero, calcium carbonate in the usual form and in the form of nano with a concentration of four per thousand) in three replications.The results showed that salinity tension reduced photosynthetic capacity and leaf chlorophyll content. As the total chlorophyll content in tension conditions showed 72 percent reduction than normal conditions. The use of sodium nitroprusside treatments had a desired effect on increasing chlorophyll content. Among the treatments of this material, application of pretreatment plus foliar application left the most positive effect on chlorophyll content. Also, salinity tension reduced the chlorophyll a / b ratio. The use of calcium treatments increased both chlorophyll a and b types. The application of salinity tension significantly increased the amount of sodium in the leaf, so that, for example, the sodium content in the leaf increased from 6.4 milligram in normal conditions to 22.7 milligram in salinity tension conditions. Also, the comparison of mean of data showed that by applying salinity tension, the amount of sesame oil decreased and the protein content of the grain was increased. So that the amount of oil in tension conditions decreased by 2.2 percent and protein content increased by 3.4 percent compared to normal conditions.

In order to evaluate the effect of the plant growth promoting bacteria and mushroom compost residues on nitrogen absorption and its translocation in common bean an experiment was conducted as a completely randomized design with four replications in Rasht during the cropping year of 2014 -2015. The experimental treatments were control (with inoculation by bacteria and non-application of compost), Azospirillum bacteria, Azotobacter bacteria, mushroom compost (2 ton per hectare), mushroom compost Azospirillum and mushroom compost Azotobacter. The results of the experiment showed that with increasing plant growth, the nitrogen concentration of the plant increased till flowering stage, but this increase continued for nitrogen absorption till the seed filling stage. The experimental treatments increased acid and alkaline phosphatase enzyme activity by 31 to 67 and 42 to 75 percent, respectively, and the treatment of the application of bacteria mushroom compost showed the highest enzymatic activity. Comparison of mean treatments indicated that Azotobacter mushroom compost treatment showed the highest amount of chlorophyll a and total chlorophyll content (11.8 and 15.8 milligram per millimeter, respectively). The highest number of root nodes (81.4 node), biological yield (6032 kilogram per hectare) and protein yield (398 kilogram per hectare) were obtained from treatment of Azospirillum mushroom compost. Also, the applied treatments increased grain yield by 11 to 49 percent compared to control treatment and Azospirillum mushroom compost treatment with 2104 kilogram per hectare was significantly superior to other treatments. The results indicate that the inoculation of plants with Azospirillum and the application of mushroom compost, while increasing the grain yield, also increases the protein content of the grain. Therefore, in order to obtain maximum grain yield of beans, it is recommended to use mushroom compost under inoculum with Azospirillum in Rasht area.

Increasing the productivity and quality of irrigation water is a key factor in solving the greatest challenge of agriculture in arid and semi-arid regions. In this research, the effect of irrigation with magnetic water and ordinary water on different levels of drought stress was investigated on morphological, physiological and biochemical properties of corn (KSC703). The present experiment was conducted in the form of factorial experiment based on completely randomized design with four replications at the research greenhouse of Imam Khomeini (RAH) International University, Qazvin in 2016. The experimental treatments were consisted of irrigation with ordinary water and magnetic water by the amount of 75, 50 and 25 percent of field capacity with control (without tension). The results showed that the measured traits were significantly affected by irrigation treatment, so that, the highest stem diameter (1.87cm), the maximum leaf width (5.92cm), the highest plant height (126cm), the highest amount of chlorophyll (45.97), the highest percentage of nitrogen (4.05 percent), phosphorus (0.39 percent) and potassium (3.78 percent) of corn leaf, was observed in the treated plants by magnetic water and without tension conditions. The highest amount of total protein (0.63 milligram per gram dry leaf) was obtained from magnetic water treatment and irrigation by the amount of 75 percent of the agricultural capacity. In general, magnetic water had a positive and significant effect on the most measured traits and could somewhat reduce the negative effect of low water in corn.

In order to investigate the effect of different plant densities on yield and yield components on rapeseed cultivars under different levels of humic acid, this factorial experiment as split plot was conducted based on a randomized complete blocks design with three replications at the research field of Seed and Plant Improvement Research Institute located in Karaj during two cropping years 2014-15 and 2015-16. Plant density and humic acid in the form of factorial were placed at main and sub plots, respectively. Densities including (40, 60, and 80 plants per meter square), humic acid (non-application or control and humic acid application) and canola cultivars (Ahmadi, Okapi, Karaj1, Opera, L72, Sw102). The results of the experiment showed that the effect of the interaction of plant density and cultivar were significant for all assessed traits, excluding plant height and seed oil percentage and the highest mean traits was obtained at the density of 40 plants per square meter and L72 line. The highest amount of seed oil yield and seed yield was obtained from the treatment of plant density of 40 plants per square meter and L72 line and whereas the lowest amount of seed oil yield and seed yield was also obtained in this cultivar from the treatment of density of 80 plants per square meter. The obtained results indicated that the traits number of pods per plant, number of seeds per pod and one-thousand seed weight and pod length and grain yield and total chlorophyll were significant with the application of humic acid treatment. In the present research, the application of humic acid through improved soil fertility and nitrogen availability increased yield and yield components, particularly, pod length. Comparison of the average of traits of leaf relative water content and total chlorophyll indicated the superiority of the density of 40 plants per square meter and the highest rank was obtained from this treatment.

In order to evaluate the effect of different pre-plant nitrogen-fertilizers (urea, ammonium sulfate, sulfur-coated urea and non-using pre-plant n-fertilizer and humic acid (using and non-using) on grain yield, yield components and nitrogen use efficiency in wheat, an experiment was conducted as a factorial based on randomized complete blocks design with three replications in Research Farm of Iranians Modern Farms Company in Varamin during 2015-2016cropping year. Results indicated that the effect of type of nitrogen-fertilizer on all under studied traits was significant. The highest plant height, biological yield, number of tillers per plant and number of spikes per square meter were obtained at urea fertilizer treatment. But the highest one-thousand grain weight, number of grains per spike, grain yield and harvest index were achieved at sulfur coated urea and application of sulfur coated urea increased grain yield by 10 and 23.2 percent, compared to urea and ammonium sulfate, respectively. Also, humic acid application increased one-thousand grain weight, number of grains per spike and grain yield of wheat by the amounts of 14.0, 17.8 and 24 percent, respectively. The application of sulfur coated urea and humic acid, increased nitrogen use efficiency. Therefore, using urea with sulfur coating as a base fertilizer and application of humic acid, can increase the grain yield of wheat while decrease nitrogen leaching.

Calcium plays an important role in plant growth and development and response to environmental tensions. However, its effect on the plant response to heavy metal tension has not been widely investigated. Therefore, in order to investigate the role of calcium on lead tension tolerance in soybean a pot experiment was conducted in Vavan region at the south of Tehran. The present research was carried out as factorial at the basis of completely randomized design with three replications. Treatments included three levels of lead (zero, 100 and 200 milligram of lead nitrate per kilogram of soil) and three calcium levels (zero, 200 and 400 milligram calcium chloride per kilogram soil). Results showed that lead tension increased lead concentration in the root, lipids peroxidation and antioxidant enzymes activity such as superoxide dismutase and catalase. Lead toxicity also reduced the traits of vegetation index, relative water content, leaf area, biomass and soybean grain yield. On the other hand, calcium application especially 400 milligram of chloride calcium per kilogram soil declined lead uptake and lipids peroxidation and further increasing superoxide dismutase and catalase enzymes activities under lead tension conditions. Calcium application improves the growth-related traits, including vegetation index, relative water content, leaf area, biomass and grain yield of soybean. These results revealed that calcium via reducing lead uptake, increasing antioxidant enzymes activity, improving plant water status and chlorophyll content can be used as a profitable tool in tolerance to lead tension in soybean.

In order to investigate the effect of drought tension after flowering on dry matter remobilization in 56 wheat genotype, the present experiment was conducted as rectangular lattice 8x7 with two replications during 2010-11 cropping year at research farm of the Campus of Agriculture and Natural Resources of Kermanshah Razi University. Results showed that there was a significant difference at one percent level among genotypes in terms of grain yield and about 27.2 percent reduction in grain yield was observed in response to drought tension after flowering. Mean comparison of yield in different wheat genotypes showed that under humidity control conditions, Darab 2, Navid and UN-11 genotypes (760, 690 and 662 gram per meter square, respectively) had the highest and Rasad cultivar (419 gram per meter square) had the lowest grain yield and also under drought tension conditions after flowering, 330 and Moghan1 genotypes by 542 and 510 gram per meter square, respectively, had the highest and Shiroudi cultivar by 187 gram per meter square had the lowest grain yield. In terms of dry matter remobilization and remobilization efficiency, lower stem internodes compared to peduncle and penultimate internode, showed superiority. Under studied genotypes had a significant difference in remobilization and dry matter remobilization efficacy. According to the obtained results, it appears that remobilization efficiency has been affected under genetic and environment and probably higher production of dry matter at flowering stage would be resulted to higher dry matter remobilization to the grain.

In order to investigate the germination characteristics, seedling growth and ionic content of alfalfa genotypes, two separate experiments each as the form of factorial were carried out in a completely randomized design with three replications in a petri dish culture (at the seed experiment) and potting at vegetative growth phase) at the Research Laboratory of Islamic Azad University, Khuzestan Research and Science Branch. In both experiments, factors including five levels of salinity tension included: zero, 4, 8, 12 and 16 dsi Siemens per meter and 10 genotypes of alfalfa included: KFA1, KFA3, KFA12, KFA15 (origin Nagorno alfalfa), KFA4, KFA5, KFA16 (origin Hamadani), KFA9 (origin Chaleshtar Shahrekord), KFA7 (origin Rehnani) and the tropical Yazdi. The results showed that salinity tension in petri dish culture decreased the traits of germination percentage and speed of germination significantly. The length of root growth and seedling dry weight, significantly decreased with increasing salinity tension Salinity tension increased sodium concentration and decreased seedling potassium. The highest amount of sodium concentration was observed in the interaction of salinity treatment of 16 dsi Siemens per meter and KFA5 genotype. The highest tension sensitivity index based on dry weight of seedling was related to KFA5, KFA7 and KFA 9(with the means of 1.26, 1.25 and 1.17, respectively). The highest amount of tension tolerance index was observed in KFA 1 and KFA15 genotypes (with the average of 0.82 and 0.79, respectively). Generally, genotypes that had a lower sodium to potassium ratio, had less sensitivity and more tolerated than salinity.