نشریه فیزیولوژی محیطی گیاهی
پیاپی 51 (پاییز 1397)

This study was performed in order to evaluate the effect of methyl jasmonate on some physiological characteristics and antioxidant activity of basil under lead toxicity, based on a factorial and completely randomized design with three replications at Ferdowsi University of Mashhad Research Greenhouse. The experimental treatments included Pb (NO3)2) at three levels of (0, 200, and 400 mg/kg soil) and foliar application of methyl jasmonate at three concentrations (0, 0.5, and 1 mM). Measured traits included chlorophyll a, b, and total, carotenoids, electrolyte leakage, relative water content, antioxidant activity, soluble carbohydrate, total phenol, and proline. Results showed that in the plants treated with lead, the amount of proline, relative water content, chlorophyll a, antioxidant activity and total phenol reduced in comparison with control plants and application of methyl jasmonate (0.5 mM) under lead stress increased these traits. Furthermore, electrolyte leakage increased significantly under lead stress, while it was decreased by spraying with methyl jasmonate. Therefore, using methyl jasmonate is justified for protecting economic performance of plants under stress. Also, application of 0.5 and 1 mM methyl jasmonate reduced and adjusted the effects of stress in the plants under lead stress through stimulating production of antioxidants.

Drought is one of the most important adverse environmental factors that limits crop production. Nitric oxide (NO) as a signaling molecule contributes in plant response to environmental stresses. Therefore, in order to investigate the effects of NO on drought tolerance of mung bean (cv. Partow), a field experiment was done in the south of Tehran in 2015. The study was conducted as a randomized complete block design with 9 treatments and 4 replications. In this experiment, sodium nitroprusside (SNP) solution was used as NO donor. Treatments included control, drought stress, seed treatment, foliar application at the vegetative stage, foliar application at the reproductive stage, seed treatment + foliar application at the vegetative stage, seed treatment + foliar application at the reproductive stage, foliar application at the vegetative and reproductive stages, and seed treatment + foliar application at the vegetative and reproductive stages. Results showed that due to the drought stress, antioxidant enzymes activities such as superoxide dismutase, catalase, and ascorbate peroxidase, as well as malondialdehyde (MDA) and proline concentrations were increased but the relative water content (RWC), chlorophyll value, leaf area index (LAI), and seed yield decreased. However, application of SNP by further increasing the activity of antioxidant enzymes and proline accumulation, reduced the MDA content while improving the RWC, chlorophyll value, LAI, and eventually the seed yield under drought stress. Among SNP application treatments, seed treatment + foliar application at the vegetative and reproductive stages was the most effective, although it was not significantly difference from the other treatments including SNP foliar application at the reproductive stage. According to the findings of the study, application of NO may be recommended as a useful tool for improving drought tolerance of mung bean.

This study was designed in order to investigate the allelopathic effect of olive fruit pomace on some physiological parameters and yield of three wheat cultivars (Triticum aestivum). A pot experiment was used based on a factorial study with completely randomized design and three replications at five levels (0, 1, 3, 5, and 7 % W/W) of olive fruit pomace and three wheat cultivars (Triticale, Karkhe and Chamran). The amount of soluble proteins of leaf, activities of peroxidase, ascorbate peroxidase, and catalase enzymes of leaf, and amount of malondialdehyde of leaf at ear emergence stage and spike weight, spike length, grain number per spike, grain weight per spike, 1000 grain weight, total harvest index, grain proline content, and grain soluble carbohydrate content at complete ripeness stage of wheat were measured. According to the results, amount of soluble proteins of leaf, activity of peroxidase of leaf, spike weight, spike length, grain number per spike, grain weight per spike, 1000 grain weight and total harvest index decreased in the three wheat cultivars with an increase in the content of olive pomace in the soil compared to the control. But the amount of activity of ascorbate peroxidase and catalase enzyme of leaf, amount of malondialdehyde of leaf, grain proline, and grain soluble carbohydrate content showed increase in the three wheat cultivars by increasing the content of olive pomace in the soil compared to the control. Since olive fruit pomace contains phenolic compounds, the inhibitory effects of olive pomace on wheat growth are attributed to these compounds.

The purpose of this study was to evaluate antioxidant activity and determining content of alkaloids, total phenols, anthocyanins, catalase, peroxidase activity as well osmolytes in vegetative,flowering and fruit stage of Chelidonium majus. Smples were collected from marginal fields of Chamestan district of Noor which is located in Mazandaran province firstly, and then collected samples were botanically authenticated.. Results showed that root of C. majus in various phenological stages had a more alkaloids and total phenols content over aerial organs in similar stages. It was also observed that the highest alkaloids and total phenols in root were obtained in vegetative and flowering stages respectively. Anthocyanins content in root and aerial organs were increased with an increase of phonological stages. Also, the measurement of soluble sugars in C. majus showed that the highest amount of this compound was in all phonological stages at the root more than the aerial parts. The maximum amount of proline was observed in the aerial parts at the vegetative stage. According to the results, enzyme of catalase and peroxidase had positive correlation with antioxidant activity. Overall, antioxidant capacity in inhibition of free radicals significantly were increased with an increase of alkaloids and total phenols content from underground and aerial organs of C. majus in various phonological stages. Overall, root of Chelidonium majus in vegetative stage had the appropriate amount of alkaloids; it may be used as a suitable source for the preparation of pharmaceutical compounds.

In order to study the effects of irrigation period and humic acid on some morpho-physiological and biochemical characteristics of Thymus vulgaris L., an experiment was conducted as split plots based on randomized complete block design with three replications at research farm of Baharan University of Gorgan, during growing season of 2016- 2017. Treatments were four levels of irrigation periods (every 3, 6, 9 days and everyday as control) and humic acid at three levels (0, 150, and 300 mg/l). Results showed that irrigation periods increased phenolic compounds, antioxidant activity, proline, and soluble carbohydrate. The effect of the longest irrigation period (every 9 days) increased 1.07, 0.016, 14.53, 1.87 and 3.82 percent of proline, phenolic compounds, antioxidant activity and soluble carbohydrate, respectively. Also the highest concentration of essential oils was observed with the every 6 days irrigation treatment showing 15% difference as compare with the control. On the other hand irrigation period decreased significantly shoot height and wet and dry weight. Moreover, humic acid had a significant effect on all characteristics under study. Also, interaction effect of humic acid and irrigation periods had significant effects on all traits except for phenolic compounds. Foliar application with 150 mg/l humic acid and every 9-day irrigation resulted in the maximum increase in thymol and antioxidant activities. The highest level of essential oils was achieved in 300 mg/l humic acid and every 6-day irrigation period. Maximum proline content was also recorded under 300 mg/l humic acid and every 9-day irrigation period. Generally, findings suggested application of 300 mg/l humic acid and every 9-day irrigation as economically the best treatment since under humic acid application and less irrigation water the same yield is achieved as under high water consumption.

Wild pears are an important rootstock for different pear cultivars and considering it is nearly tolerant to drought stress it is necessary to use different treatments to increase its tolerance to drought stress. Electrolytes leakage is an important and effective factor in response to drought stress and related traits. For this purpose, a factorial experiment was designed in a randomized complete blocks design with three replications to identify the traits affecting electrolytes leakage. These traits were studied in 12 treatments including different levels of drought stress and different concentrations of brassinosteroids on wild pears in spring and summer of 2017 in greenhouse conditions. The result showed a positive significant correlation between proline content (0.83**), malondialdehyde (0.98**), hydrogen peroxide and electrolyte leakage. The correlation for dry weight of root, leaf and stem, height growth, chlorophyll a, b and carotenoid was significantly negative. Stepwise regression analysis indicated that chlorophyll a, leaf dry weight, height growth and hydrogen peroxide were the most important effective traits on electrolytes leakage and showed 99% of total variance. Based on the path analysis results, the traits of electrolytes leakage and height growth and chlorophyll a showed the maximum positive direct and significant at p

A split plot experiment was conducted to investigate the seed and essence yield of borage (Borago officinalis L.) under the influence of type and method of application of nanofertilizers based on a complete random block design with arrangement of split plot-factorial in three replications at Faculty of Agriculture, Islamic Azad University, Tabriz Branch in 2013. Fertilizers at 11 levels (Iron sulphate, nano-iron %10, Zinc sulphate, nano-zinc %20, urea and nano-urea, sulphate-potash, nano-potash %23, complete micro fertilizer, nano-complete micro-fertilizer, and control) along with different methods of application including (soil application, foliar application, and soil + foliar application) were considered. Results showed that use of urea fertilizer increased dry weight of shoots and plant height compared with the control group. The use of Nano-urea fertilizer could also significantly increased leaf area, harvest index, flower essence and essential oil yield compared to the control. Application of chemical and nanofertilizers of urea and potash had the most increasing effect on shoot dry weight and flower essential oil. Application of nano-urea increased essence production. Considering the desirable effects of nanofertilizers in comparison with chemical fertilizers, the use of nanofertilizers is suggested as an effective step toward sustainable agriculture.

In order to investigate the effects of nanofertilizers (Fe, Zn, and Mn), Bioumik biological fertilizer, and drought stress on the economic yield of the sepal, antioxidant enzymes, and concentration of some elements in roselle plants under drought stress, a spilt plots experiment was conducted in a randomized complete block design with three replications at Research Farm of the University of Zabol in 2015. Experimental treatments included drought stress at 4 levels (30, 50, 70, and 90 percent available moisture) as the main factor and four levels of fertilizers (no fertilizer, nano-iron, iron compounds, and nano-biological fertilizers) as the sub-agent. The main effects of drought stress, fertilizer, and their interactions on all traits were significant at P≤0.01. The highest fresh and dry weights were obtained under nano-iron fertilizer and 70 percent drought tolerance. Nano-iron fertilizer and 30 percent available moisture content resulted in the highest levels of catalase, guaiacol peroxidase, and ascorbate peroxidase enzymes. Application of nano-iron fertilizer increased the concentration of micro and macro elements (Fe, Zn, Nitrogen, Phosphorus, and Potassium) in the plant and the highest concentrations of the elements were observed in the interaction of nano-iron fertilizer with drought stress at 70 percent capacity of the pot. In general, it can be said that stress has a destructive effect on the plant, the use of nano-iron increases plant tolerance to stress, and the use of Roselle plant is suitable for stress conditions.