نشریه فیزیولوژی گیاهان زراعی
پیاپی 31 (پاییز 1395)

In order to investigate the effect of nip and drought tension on chlorophyll index, relative water content, electrolyte leakage and grain yield of maize single cross 400 under different levels of salicylic acid, a field experiment carried out in split split plots in randomized complete block design with three replications in the greenhouse and Agricultural Research Station of Ferdowsi University of Mashhad during the cropping year of 2014. In the present experiment the main factor, cold tension at two levels (non- nip tension and nip tension), sub-factor included three levels of drought tension (irrigation equivalent to 100 percent plant water requirement (non-tension, control)), irrigation equivalent to 75 percent of plant water requirement and irrigation equivalent to 50 percent plant water requirement) and sub sub factor foliar application salicylic acid (non-foliar application (control), foliar application 200 micro molar and 400 micro molar foliar application) was considered. The obtained results indicate chlorophyll meter index, relative water content and electrolyte leakage are influenced under drought tension conditions; as water deficiency tension, chlorophyll index decreased relative water content and electrolyte leakage, increased grain yield. Also, salicylic acid foliar application improved the chlorophyll index, leaf relative water content, increasing electrolyte leakage and grain yield. Nip treatment interaction on drought tension using 200 micro molar foliar application of salicylic acid improved the chlorophyll index. According to the results, using the appropriate concentration of salicylic acid are recommended for improving environmental tensions such as drought and nip to achieve the optimal performance.

This research was carried out in order to biomolecular investigate drought tension tolerance in two wheat cultivars inoculated with plant growth promoting rhizobacteria (PGPR) in the research greenhouse of Islamic Azad University, Karaj Branch in 2013-14 cropping year. The experiment design was in the split factorial arrangement based on a randomized complete blocks design with three replications. The main plot included two levels of desirable irrigation and drought tension (deficit irrigation in the pollination stage until the end of full maturity) and sub plots consisted the PGPR bacteria at four levels: 1) inoculation seed with Azotobacter chroococcum 2) inoculation seed with Azospirillum lipoferum 3) simultaneous use of both bacteria Azotobacter Azospirillum 4) non-application of bacteria (control) and two bread wheat cultivars consisted of Sirvan and Marvdasht. Experiment traits included the activity of superoxide dismutase antioxidant enzyme (SOD), the activity of biochemical biomarker Malondialdehyde (MDA) amount of chlorophyll a, b and a b. Results of the experiment showed that simple effect of irrigation, cultivar and bacteria treatments was significant on all the studied traits (01 / 0≥P). The activity of superoxide dismutase enzyme (SOD) in drought tension treatment was higher than full irrigation (normal). Sirwan and Marvdasht cultivars with 3.6 and 2.7 units per gram of protein, showed the higher and lower SOD enzyme activity, respectively. Sirvan cultivar compared to Marvdasht cultivar had less amount of biomarker MDA activity (27.424 milligram on gram fresh weight of tissue) and the higher content of chlorophyll a, b and a with 3.255, 1.578 and 4.811 (milligram on gram fresh weight of tissue), respectively.

In order to investigate the effect of cycocle and Azotobacter and Pseudomonas inoculation with seed on quantitative and qualitative yield, rate and grain filling period of wheat under water limitation conditions, this experiment as factorial based on randomized complete blocks design with three replications was conducted at the research farm of Faculty of Agricultural Sciences, University of Mohaghegh Ardabili, during 2014-15 cropping year. The first factor included irrigation levels at three levels (full irrigation, irrigation to 50 % of heading and irrigation to 50 % of booting stage, equivalent to 45 and 59 Zadoks code, respectively), and the second factor included seed inoculation with bio fertilizers at four levels (without inoculation as control, seed inoculation with Azotobacter chrocoocum strain 5, Pseudomonas putida strain 186 and simultaneous using of both Azotobacter Pseudomonas) and the third factor included foliar application of cycocle at four levels ( non- consumption, 400, 800 and 1200 milligram per liter of cycocle). The results showed that the effect of water limitation, cycocle and bio fertilizers on grain filling period (at one percent probability level) and quantitative yield (at five percent probability level) and protein content (at one percent probability level) was significant. The highest grain yield (3822 kilogram per hectare) was obtained from foliar application treatment combination of 1200 milligram per liter cycocle, seed inoculation with Azotobacter and Pseudomonas under normal irrigation conditions and the least of it (1409.7 kilogram per hectare) was obtained to non-application of cycocle and non-inoculated seed at irrigation cut conditions at booting stage. Applying irrigation cut at booting stage resulted in the maximum reduction in most traits related to yield and yield components and maximum photochemical efficiency of II in wheat.

This experiment was conducted in split split plots arrangement in a randomized complete blocks design with three replications at the field of Shahid Salemi Ahvaz in 2014. In this experiment the effect of three levels of irrigation after 60 (desirable), 100 and 140 millimeter evaporation from evaporation pan and three levels of pure nitrogen 120, 180 and 240 kilogram per hectare and two levels of the presence and absence of weeds were compared. Different levels of irrigation and nitrogen in main plots and sub plots, respectively; and weeds treatment in the sub sub plots were maintained. The results indicated that effect of different levels of irrigation on leaf area index, total dry matter, crop growth rate, net assimilation rate and grain yield of maize was significant. The growth indices and grain yield were decreased with increasing duration of irrigation. The treatment of 140 millimeter evaporation from evaporation pan led to decrease the leaf area index and grain yield by the amount of 37.7 and 35.6 percent as compared to treatment of 60 millimeter evaporation from evaporation pan. Increasing nitrogen level from 120 to 240 kilogram per hectare significantly increased the leaf area index, total dry matter, crop growth rate and maize grain yield by 9.6, 9.7, 14.4 and 13.6 percent. Also, leaf area index, total dry matter, crop growth rate and grain yield in the conditions of presence of weed in comparison with the absence of weed significantly reduced. Results of present study showed that irrigation levels as compared to nitrogen and weed competition is more effective factor on growth indices and grain yield of maize. Therefore, in areas with limited water resources, increasing application of nitrogen is not necessary. It seems that irrigation levels through the impact on leaf area index, affect other the physiological indices and ultimately leads to a reduction on maize grain yield.

In order to investigate remobilization efficiency and wheat grain yield, this research was conducted as two factorial experiments using a randomized complete blocks design with three replications at two sites in Ilam and Bushehr during 2013-14 cropping year. The experimental factors were including application of two levels of Chlormequat chloride concentration (zero and 2.5 gram per liter), Zinc sulfate at the three rates (zero, 25 and 50 kilogram per hectare) and Nitroxin at two levels (seed inoculated and non-inoculated). The results showed that Chlormequat chloride application had significant effect at one percent probability level on spike to stem dry weight ratio and remobilization rate of dry matter of stem. With consumption of 2.5 gram per liter Chlormequat chloride, spike weight to stem compared to control increased by the amount of 20.4 percent and remobilization rate of stem dry matter decreased to 2.4 percent. In addition, application of Chlormequat chloride had significant effect on yield and grain yield components and water use efficiency at the statistical probability level of one percentage. Chlormequat chloride foliar application increased spike number per meter square, grain number per spike, grain yield and water use efficiency by the amount of 14.6, 19.1, 28.5 and 29.3 percentages, respectively. The highest amount of remobilization (64.8 gram per square meter), remobilization efficiency (32.1 percentage) and contribution of remobilization (50.8 percentage) was related to interaction treatment without application of Chlormequat chloride, using 50 kilograms per hectare of zinc sulfate and using Nitroxin. The highest grain yield (1710 kilogram per hectare) from the interaction of foliar application treatments of Chlormequat chloride at concentration of 5.2 gram per liter, application of 50 kilogram per hectare zinc sulfate and inoculation of seed with Nitroxin was obtained. Generally, it can be concluded that, the application of Chlormequat chloride, zinc sulfate and Nitroxin might be effective in improvement and increasing the grain yield of wheat under dry land farming conditions.

In order to identify the drought tolerance lines and screening quantitative indices of drought tolerance, 10 barley breeding lines in two separate experiments in randomized completely blocks design with three replications were evaluated at two conditions of full irrigation (first experiment) and irrigation cut when rise of 50 percent of spike (second experiment) in Agricultural Research Station of Islamic Azad University Isfahan Branch in 2012-13 cropping year. Based on yield at full irrigation conditions and drought tension at the end of the growing season, drought tolerance quantitative indices such as: mean productivity, tolerance index, yield geometric mean, sensitiveity index to tension and tension tolerance index was calculated. Effect of drought tension on the number of grain per spike, one-thousand grain weight and grain yield was significant. The results of the means comparison showed that the highest mean yield in non-tension conditions was belonged to line Arbayan and in tension conditions to Malouh line. The highest tolerance index to tension was related to Manal and Malouh genotypes and the highest sensitivity index to tension was related to chek-1¡ GloriaS, Rebelle and QB813 genotypes. The obtained results of the analysis of the correlation between indices and mean yield in irrigation tension and non-tension conditions showed that the best indices for screening lines in both conditions are the average indices of productivity, mean geometric yield and tension tolerance index. Based on these indices and high yield in two aqueous and tension environments, the best drought tolerant lines that had high yield in both aqueous and tension environments, were detected ABYTD-2 and Akrask lines.

Drought tension is one of the most important determinants of crop production, therefore, this study aimed to investigate the effect of drought tension on wheat genotypes, as a completely randomized factorial statistically design was conducted under greenhouse conditions. The experimental treatments has consisted of three levels of drought tension (85, 60 and 35 percent of field capacity) and eight genotypes of wheat (Omid, Zarea, Mihan, ZSZOBKAYKA, JS3l7G217, Solh, G13CA2242O4P, and FAA3P4FCCC). The results indicated that there was significant difference between wheat genotypes in terms of remobilization of dry matter from the stem, leaf, peduncle, the whole plant and spike. Also, the efficiency of the remobilized dry matter of shoot, leaf and total and proportion of transferred dry matter from stem and total, was significant. Zare genotype was allocated the highest dry matter transferred of stem and leaves. Omid and JS3l7G217 genotypes had the highest efficiency of dry matter transferred from stem and Omid and Zare genotypes had the highest efficiency of dry matter transferred from peduncle.The highest proportion of transferred dry matter of leaf to seed was observed of genotypes Zarea and G13CA2242O4P. Also, wheat genotypes had significant differences in terms of plant height, peduncle length, number of grain per spike, one-thousand grain weight, and grain yield and harvest index. The highest plant height was allocated to genotypes Solh, Mihan and JS3l7G217 and the maximum spike length was belonged to genotypes FAA3P4FCCC and ZSZOBKAYKA under 85% field capacity. The highest and lowest one-thousand seed weight were obtained from genotypes Solh and JS3l7G217, respectively. Genotype ZSZOBKAYKA by producing 1.53 gram grain per plant under 85% field capacity and JS3l7G217 genotype by 0.39 gram per plant under 35% field capacity devoted the highest and lowest grain yield.

In order to investigate the effect of selenium application on quantity and quality of oil yield in canola cultivars under delayed planting conditions, the present experiment was conducted as a factorial split plot arrangement based on randomized complete blocks design with three replications, at field research of Seed and Plant Improvement Research Institute located in Karaj, in two cropping years during 2013-14 and 2014-15. The first factor was, planting date in three levels included planting on 7 October (on time planting), 17 October and 27 October (delayed planting), the second factor selenium in two levels included non-application and application of 30 gram per liter per hectare selenium and cultivar and line, included Opera, L72, KR1 GKH3705, GKH0224 and Neptune as the third factor, in which the first and second factor was assigned as factorial in the main plots and the third factor as the split plot in the sub plots. The results of experiment indicated that the planting date and cultivar and dual interaction between planting date and cultivar, was significant on all of the studied traits. Grain yield and grain oil yield increased due to selenium application. Based on the mean comparison of interaction of the three treatments, the highest percentage of Palmitoleic acid changes due to the application of selenium, on L72 cultivar in planting date of 7 October (61.9 percent), on Opera cultivar planting date of 17 October (22.2 percent) and on GKH3705 cultivar in planting date 27 October (16.5 percent) was observed. The most increase in grain yield was observed in L72 line (5853 kilogram per hectare)and oil grain yield (2576 kilogram per hectare) in normal planting conditions, but Opera cultivar in delayed planting conditions showed the highest value of this trait. Most of the increase in grain yield was obtained due to the use of 30 gram per liter per hectare of sodium selenite, in delayed sowing conditions, in line KR1 (4/13 percent) where led to increasing yield of this cultivar from 2536 to 2876 kilogram per hectare.