نشریه فیزیولوژی محیطی گیاهی
پیاپی 45 (بهار 1396)

Given the importance of Giant Milkweed shrub in reclamation of deserts and arid regions, and position of Iran in low rainfall and arid areas, so far enough research has not been done to understand the morpho-physiological properties of the Giant Milkweed shrub under drought stress conditions and to determine the status of putrescine in reducing the devastating effects of drought. For this purpose, a field experiment was conducted in a split plot randomized complete block design with four replications to determine the effect of putrescine on some morphological and physiological characteristics of Giant Milkweed seedlings under drought stress conditions in Research Farm of the University of Hormozgan. The main factor included five levels of irrigation (1 (control), 3, 6, 9 and 12 days irrigation intervals) and putrescine treatment by foliar sprays at 3 steps every 20 days at five levels (0, 0.5, 1, 1.5, 2 mM) in sub plots. Results showed that an increase in irrigation interval up to 12 days reduced leaf area, fresh and dry weight of shoots, fresh and dry weight of roots, and chlorophyll content. Also, increased irrigation interval up to 12 days increased proline content, superoxide dismutase, catalase, ascorbate peroxidase, and peroxidase enzymes activities. Increase in the concentration of putrescine, led to a significant increase in leaf area, fresh and dry weights of shoots and roots, chlorophyll content, proline content, and superoxide dismutase, peroxidase, and ascorbate peroxidase enzymes activities in the leaves. The best putrescine treatment to reduce the devastating effects of drought was observed at concentration of 2 mM. According to the results obtained, the use of putrescine to establish the plant in dry conditions is recommended.

To evaluate the quality and quantity of primary and secondary metabolites at different phenological stages of Brazmbl medicinal plants, plant organs at both vegetative and flowering stages of Vamanan region in Āzādshahr were collected and dried. Whole plant extracts from Proveskia abrotanoides were used in this study at both vegetative and flowering stages to identify and evaluate the quality of tannins, saponins, anthocyanins and terpenoids compounds, flavones, and flavonoids. Also some primary metabolites such as soluble and insoluble carbohydrates, proline and total phenol in roots, stems, leaves, and flowers of plant were evaluated quantitatively. Qualitative analysis showed that saponins, anthocyanin, and tannin compounds were present at both vegetative and flowering stages of Proveskia abrotanoides. Also, quantitative analysis showed the maximum amount of starch in the root and the highest concentration of soluble carbohydrates, proline, and phenolic compounds in the leaves at vegetative stage. Overall, the results showed that at the vegetative stage regardless of starch, leaves had the highest soluble carbohydrates, proline, and phenolic compounds while at the reproductive stage root contained the highest level of these compounds.

This research was carried out during the growing seasons of 2013-2014 and 2014-2015 at Agricultural Research Station, Faculty of Agriculture, University of Tehran in Karaj. The aim was to evaluate the effect of iron foliar application on yield, yield components, and protein content of lentil under rain-fed conditions. A randomized complete block design with three replications and seven treatments (non-foliar application (control), 2 (g L-1) foliar application of nano fertilizer at flowering, podding and flowering podding stages and 4 (g L-1) foliar application of nano fertilizer at flowering, podding and flowering podding stages) were used. Analysis of variance showed that the effects of iron foliar spraying on grain yield components, biological and grain yield, harvest index, grain iron and protein content, and grain protein yield were significant. However, the effect of year of plantation was not significant on these properties. Comparison of means showed that maximum values for the number of grain per plant, 1000-seed weight and grain yield and grain protein yield, and grain iron and protein were achieved at 4 (g L-1) foliar application of nano fertilizer at flowering podding stage treatment. However, there was no significant difference for grain yield and grain protein yield between 4 (g L-1) and 2 (g L-1) foliar application of nano fertilizer at flowering podding stage treatments. Therefore, foliar application of nano-iron chelate at flowering podding stages can produce the highest agronomic indices and grain yield. Alpha

Some physiological parameters and antioxidant responses were investigated in different color leaves of the evergreen shrub Japanese spindle (Euonymus japonica Thunb.). The shrub has leaves with three colors including dark green, light green, and yellow. Oxidative stress markers (hydrogen peroxide concentration, cell membrane stability, and lipids peroxidation), activity of peroxidase and some antioxidant molecules (phenolic compounds, proline, and free amino acids) were studied. Significant differences were found in hydrogen peroxide content, cell membrane stability, and membrane lipids peroxidation among leaves. In yellow leaves, the total content of proline and free amino acids were higher than those of the dark green and light green leaves. The highest and lowest free phenolic compounds contents were found in the dark green and yellow leaves, respectively. The POD activity increased significantly with changing leaf color from dark green to light green and to yellow. As a result, despite the activity of the antioxidant systems, the color change from dark green to yellow caused a gradual increase in the oxidative damage.

In order to study the effect of zeolite on some physiological characteristics, antioxidant enzymes activity, seed and oil yields of rapeseed (Brassica napus L.) under drought stress condition, a split plot factorial experiment was conducted based on a randomized complete block design with four replications in Seed and Plant Improvement Institute in Karaj. Three drought stress levels (irrigation after 40, 60, and 80% soil water discharge), were applied as non-stress, low stress, and high stress, respectively and the zeolite at two levels (0 and 10 tons per hecater) was applied in a factorial design in main plots while genotypes of rapeseed (Line KR4 and Eldo and GKH 305 and Anatol cultivars) were used in sub-plots. Results revealed that in all zeolite and rapeseed genotype treatments, drought stress caused a decrease in relative water content, canopy temperature, and stomatal resistant and decreased soluble sugar, proline content, and antioxidants activity (catalase and peroxidase) and malondealdehyde in top young leaves in plant. The moderate and severe drought stress led to reduction in seed yield and oil yield, respectively. With an increase in stress level, so did the efficiency of zeolite in reducing negative effects of stress and its application under moderate and high stress resulted in significant reductions in catalase and peroxidase antioxidant activities and also reduction in soluble sugars and proline concentration. Application of zeolite increased seed yield significantly under non-stress, moderate and high stress treatments and improved oil yield. Among genotypes under study, KR4 line and GKH305 cultivar had the highest seed yield in case of application and non-application of zeolite, respectively but under moderate and severe stress, Anatol had the lowest loss and highest yield. According to the findings, using zeolite in all drought stress caused a significant decrease in rapeseed yield and with an increase in water limitation, so did the efficiency of zeolite.

The objective of the present study was evaluation of the effects of different nitrogen fertilizer sources (urea, ammonium nitrate, and ammonium sulfate) and levels (0, 50, 100, and 150 kg/ha) on growth parameters, chlorophyll, oil and essence contents of black cumin (Nigella sativa L.). The experiment was conducted based on a complete randomized block design with 3 replications in a farm field near Gorgan. The results indicated that the highest number of flowering branch, plant dry weight, number of capsule per plant, number of seeds per capsule, harvest index, biological yield, seed yield, oil yield and percentage, essence yield and percentage, and chlorophyll a, b and total content were observed in 150 kg/ha urea. The number of flowering branch, chlorophyll a, b and total content and essence and oil percentage achieved to their maximum amount following use of 50 kg/ha urea, however, harvest index, biological yield, seed yield, oil yield and essence yield increased by increment of level of urea fertilizer up to 150 kg/ha. Ammonium nitrate and ammonium sulfate fertilizers increased most of the studied parameters including biological yield, seed yield, oil yield, and essence yield compared with control and ranked 2nd and 3rd after urea, respectively. Application of ammonium nitrate and ammonium sulfate fertilizer beyond 50 kg/ha resulted in no significant effect on these parameters. The data indicated that 150 kg/ha urea could resulted in the highest growth and oil and essence yield. Further experiments in other climates and soil condition are suggested.

In order to investigate the effect of foliar application of methanol and drought stress on some biochemical properties of soybean (Glaycine max L.), a pot experiment was done in farm environment. The experiments were done in factorial form based on a completely random design with 3 repetitions. Treatments included three irrigation levels of normal (irrigation after 40% depletion of available soil moisture), average stress (irrigation after 60% depletion of available soil moisture), and severe stress (irrigation after 70% depletion of available soil moisture) as the main factor and levels of methanol in the form of foliar application including control solutions (foliar application without use of methanol) and solutions of 14.7% and 21% of methanol as secondary factor. Results obtained from the study showed that there were significant differences between various levels of methanol in content of chlorophyll and carotenoid compounds, relative water content, phenolic compounds, total protein content, proline, and leaf peroxide hydrogen in (P≤0.01). With the application of stress from mild to severe, application of 14% methanol showed more pronounced effects on total chlorophyll content, chlorophyll a and chlorophyll b. Moreover, under mild and severe stress conditions, with application of the highest value of methanol, production of peroxide hydrogen reached lowest level and the content of phenolic compounds increased with the increased application of methanol from 7% to 14%. According to the obtained results, with application of 14% methanol, more increase was observed in the efficiency of proline under severe stress conditions. Increasing the volume of methanol from 7 to 14%, the relative water content was preserved under stress conditions. For protein, with increased drought stress, the effect of application of 14% methanol was the same in comparison with 21% methanol. Therefore, according to the obtained results, it is concluded that methanol could improve plant resistance against drought stress.

To evaluate the application methods of nitroxin and nitrogen fertilizers on yield and physiological traits of maize (SC 704), a field experiment was carried out in Ahvaz based on a split plot randomized complete block design with three replications during 2013-2014. The treatments included four levels of nitrogen fertilizer (N1:100%, N2: 75%, N3:50%, N4: 25%) pure nitrogen (equivalent to 180 kg per hectare) as the main factor and nitroxin biological fertilizer application method at two levels (seed inoculation B1 and with irrigation water B2) as the secondary factor. The results showed that nitrogen fertilizer significantly increased grain yield and physiological traits. The highest and lowest grain yields were obtained in 75% and 25% nitrogen treatments respectively. The biological fertilizer, nitroxin, had a significant impact on performance, chlorophyll a and b, efficiency, and NAE. The highest grain yield was recorded in B1 (seed treatment). In this study, while method of application of nitroxin showed no significant effect on the traits under study, the combined use of bio-fertilizer with N fertilizer, in addition to producing sufficient crop and improving nitrogen uptake efficiency, could reduce the use of nitrogen fertilizer by 25 percent.