Mina Amani; Mohsen Sabzi-Nojadeh
Abstract
Objective: The increasing global population and the growing demand for medicinal plants in the pharmaceutical industry highlight the importance of active compounds derived from these plants across various sectors. This trend has led to a significant rise in the cultivation of medicinal plants, particularly ...
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Objective: The increasing global population and the growing demand for medicinal plants in the pharmaceutical industry highlight the importance of active compounds derived from these plants across various sectors. This trend has led to a significant rise in the cultivation of medicinal plants, particularly Moldavian balm (Dracocephalum moldavica L.), which has gained popularity worldwide. However, as the cultivation of Moldavian balm expands, it is likely to encounter abiotic stresses, particularly water deficit stress, during its growing season. Drought stress can severely affect plant health by disrupting physiological and metabolic functions. In this context, melatonin has emerged as a crucial regulator of plant biological responses, modulating various physiological processes and enhancing resilience to stress conditions. Therefore, considering the limited water resources in the country and the positive effects of melatonin on plants, as well as the medicinal importance of Moldavian balm, this research was conducted with the aim of investigating the effect of melatonin on improving the physiological properties of the medicinal plant Moldavian balm in greenhouse cultivation.
Method: In this study, we investigated the effects of different concentrations of melatonin (such as control, 50, and 100 micromolar) on the physiological characteristics of Moldavian balm subjected to varying levels of drought stress (including 25%, 50%, 75%, and 100% of field capacity). The experimental design employed was a factorial arrangement in a completely randomized block design with three replications, allowing for robust statistical analysis of the results. This experiment was conducted in the greenhouse and laboratory of the Faculty of Agriculture and Natural Resources, Ahar, University of Tabriz.
Results: The application of 100 µM melatonin significantly enhanced the levels of photosynthetic pigments in Moldavian balm. This increase is crucial as chlorophyll and carotenoids are vital for photosynthesis, enabling plants to convert light energy into chemical energy efficiently. Enhanced photosynthetic activity directly correlates with improved growth and productivity, especially under stress conditions. The study revealed that melatonin treatment, particularly at the 100 µM concentration, led to a marked increase in secondary metabolites, including phenolic compounds and flavonoids. These compounds are known for their role in plant defense mechanisms, providing protection against environmental stressors, including drought. The highest recorded levels of phenol (51.952 mg gallic acid g-1 FW) and flavonoid (11.424 mg quercetin g-1 FW) were observed in the melatonin-treated plants, indicating enhanced protective capabilities. The activity of antioxidant enzymes, specifically phenylalanine ammonia-lyase, was significantly elevated in the melatonin-treated plants. This enzyme plays a crucial role in the biosynthesis of phenolic compounds, which are instrumental in combating oxidative stress. The recorded activity of 17.84 µM cinnamic acid min. mg-1 protein under severe drought conditions (25% of field capacity) underscores the protective role of melatonin in enhancing plant resilience.
Conclusion:The findings of this study clearly demonstrate that melatonin can serve as an effective agent in reducing the damage caused by drought stress in Moldavian balm. By enhancing photosynthetic efficiency, increasing secondary metabolite production, and boosting antioxidant enzyme activity, melatonin not only helps plants withstand unfavorable environmental conditions but also improves their overall quality and yield.
Mohamad Keshtegar khajedad; Alireza Sirousmehr; Issa Khammari; Khodadad Dahmardeh
Abstract
Water deficit is one of the most important limiting factors of production in crops. The present study was conducted in 2019 to investigate the effect of different irrigation times and foliar application of humic acid on morphophysiological traits and yield of black beans as a split plot in a randomized ...
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Water deficit is one of the most important limiting factors of production in crops. The present study was conducted in 2019 to investigate the effect of different irrigation times and foliar application of humic acid on morphophysiological traits and yield of black beans as a split plot in a randomized complete block design with three replications at Zahak Agricultural Research Station in Sistan and Baluchestan Province. The main factor involves three irrigation treatments, including irrigation from planting to harvest, irrigation from planting to flowering, and irrigation from flowering to harvest, and the secondary factor includes foliar application at four levels of humic acid (0, 1, 2, and 3 per thousand). By increasing drought stress levels, plant height and width, fresh and dry forage yield, leaf area (in both stem and flowering stages), photosynthetic pigments, nitrogen, phosphorus (3.39%), potassium (20.6%), calcium of leaf, grain yield (11.27%), and biological yield (60.22%) has decreased, whereas proline content (31.88%) has increased, compared to the control. Also, by increasing humic acid levels, the values of all studied traits has increased. Humic acid has had a positive effect on black bean plant traits under drought stress conditions, so that its concentration of three per thousand reduces the adverse effects of drought stress, increasing the tolerance of black bean crop. In general, complete irrigation and application of three per thousand humic acids for the production of black beans seems appropriate. It is suggested that in future research, soil application of humic acid consumption should be investigated to compare the efficiency of the methods used.
Amir Mizani; jafar masoud sinaki; Shahram Rezvan; Mohammad Abedini-Esfahlani; Ali Damavandi
Abstract
This experiment works on the physiological, growth, and yield responses of sesame to the application of potassium nano-fertilizers, chitosan, and fulvic acid under drought stress in Semnan Agricultural and Natural Resources Research Center as a factorial split-plot based on randomized complete block ...
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This experiment works on the physiological, growth, and yield responses of sesame to the application of potassium nano-fertilizers, chitosan, and fulvic acid under drought stress in Semnan Agricultural and Natural Resources Research Center as a factorial split-plot based on randomized complete block design with three replications in 2019. The experimental treatments include drought as the main plot (normal irrigation, irrigation cut offin 70 and 60 BBCH as moderate, and severe stress, respectively) and potassium nano-fertilizer (0, 1.5, and 2.5 per thousand) and foliar application (control, chitosan, fulvic acid, and 50% of chitosan+ fulvic acid) as sub-plots.Application of potassium nano-fertilizer under normal and stress conditions significantly cuts chlorophyll b and total, leaf area index, number of capsules, 1000-seed weight, and oil percentage.The highest grain yield belongs to the application of 1.5 and 2.5 per thousand nano fertilizers, using fulvic acid alone or in combination with 50% chitosan (2516, 2277.5, 2506.6, and 2313.2 kg/ha, respectively). The highest oil content has been in 1.5 and 2.5 per thousand nano fertilizer application under normal irrigation, which has increased 13.2% and 15.4%, respectively. Foliar application of fulvic acid with nano potassium fertilizer (1.5 per thousand) under severe drought stress show the highest activity of antioxidant enzymes catalase, peroxidase, ascorbate peroxidase, and superoxide dismutase. In general, the results show that the application of 1.5 per thousand nano potassium fertilizer and combined foliar application of chitosan and fulvic acid under severe drought by improving physiological traits, manage to modify the adverse effects of drought, increasing growth, yield, and quality indices of sesame.
jaber khordadi Varamin; Farzad Fanoodi; jafar masoud sinaki; Shahram rezvan; Ali Damavandi
Abstract
To investigate the physiological responses of sesame cultivars to the application of nano magnesium and chitosan biopolymer under different irrigation regimes, a split factorial based on randomized complete block design has been conducted with three replicates between 2017 and 2018. The irrigation cut-off, ...
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To investigate the physiological responses of sesame cultivars to the application of nano magnesium and chitosan biopolymer under different irrigation regimes, a split factorial based on randomized complete block design has been conducted with three replicates between 2017 and 2018. The irrigation cut-off, based on BBCH scale, has served as the main factor (normal irrigation, irrigation up to 50% flowering, and seed ripening), with the sub factors including Oltan and Dashtestan-2 sesame cultivars, and nano magnesium (application and non-application) and chitosan (control, 4.8, and 6.4 g.L-1). The highest mean grain yield belongs to the application of 6.4 g.L-1 chitosan under normal irrigation with an average of 1235.1 kg.ha-1. Also, the highest total chlorophyll content is observed in Dashtestan-2 genotype under normal irrigation with a mean of 24.7 mg.g-1 FW and the lowest mean have been obtained in both genotypes under irrigation up to 65 BBCH with a mean of 17.21 and 17.46 mg.g-1 FW, respectively. Application of nano fertilizer in Oltan genotype under irrigation up to 65 BBCH increases the catalase activity by 41.11%, compared to the control treatment. The highest activity of ascorbate peroxidase has been achieved when not applying chitosan under irrigation conditions up to 65 BBCH. It has risen by 55.06%, compared to the control treatment. In general, the results show that irrigation up to 65 BBCH reduces grain yield, in turn alleviated by the negative effects of stress on magnesium and chitosan nanoparticles (9.93% and 27.46%, respectively). Based on the regression analysis results, four traits, namely chlorophyll b, total chlorophyll, proline, and catalase, enter the model that explains 42.11% of the total grain yield variations. Results of simple correlation between traits and regression analysis indicate the indirect effects of physiological traits on grain yield and among the studied parameters, photosynthetic pigments has been of high account in stress conditions.
fatemeh aghaei; Raouf Seyed sharif; hamed narimani
Abstract
In order to study the effect of 0.05 g.L-1 Uniconazole and biofertilizers application on yield, chlorophyll content and grain filling components of wheat using segmented model under soil salinity conditions, an experiment was carried out as factorial based on randomized complete block design with three ...
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In order to study the effect of 0.05 g.L-1 Uniconazole and biofertilizers application on yield, chlorophyll content and grain filling components of wheat using segmented model under soil salinity conditions, an experiment was carried out as factorial based on randomized complete block design with three replications. Factors were included soil salinity in four levels (non-application of salinity as control and 40, 80 and 120 mM salinity in soil), by NaCl and single and combination application of Uniconazole and bio fertilizers (1) control or without bio fertilizers and Uniconazole, (2) mycorrhiza fungi, (3) Uniconazole, (4) Pseudomonas putida, (5) mycorrhiza with Pseudomonas putida, (6) mycorrhiza with Uniconazole, (7) both application of mycorrhiza with Uniconazole and Pseudomonas). A segmented model was used to quantifying the grain filling parameters. The results showed that both application of mycorrhiza with Uniconazole and Pseudomonas under no salinity condition increased the content of chlorophyll a, total chlorophyll, carotenoid, root weight and volume (39.8, 51.6, 47.2, 97.9 and 54.7% respectively) and also maximum of grain weight, grain filling period, effective grain filling period and grain weight (78.4, 21.8, 32.2 and 108.8% respectively) in comparison with no application of bio fertilizers and Uniconazole under the highest soil salinity level. Based on the results, bio fertilizers and Uniconazole application can be suggested as a proper approach for increasing of yield and grain filling period of wheat under soil salinity condition.
Seyedeh Esmat Hashemi Fadaki; Barat Ali Fakheri; Nafiseh Mehdi Nezhad; Roqia Mohammad Pour
Abstract
The replacement of chemical inputs with ecological compatible inputs seems necessary for a step towards in transition from common to sustainable agriculture. In this regard, an experiment was conducted at the research field, University of Zabol, as a split plot based on randomized complete block design ...
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The replacement of chemical inputs with ecological compatible inputs seems necessary for a step towards in transition from common to sustainable agriculture. In this regard, an experiment was conducted at the research field, University of Zabol, as a split plot based on randomized complete block design with three replications, during 2015. Four drought stress levels of 30, 50, 70 and 90 percent of available water were considered as main plots and four levels of nano and nano bio-fertilizers were considered as sub plots. Main effects of fertilizer, drought stress and their interaction were significant for all studied traits. Maximum of photosynthetic pigments, fresh and dry weight of sepals were obtained under treatment of 70% of available water irrigation and foliar application of nano-iron fertilizer. The highest amount of anthocyanin, proline and carbohydrate osmolytes belonged to 30% of available water irrigation and the highest relative water content of leaves belonged to 90% of available water irrigation and foliar application of nano-iron fertilizer. The result of principal component analysis showed that the best-studied treatment was 70% of available water irrigation including with foliar application of nano-iron fertilizer. Spraying nano-iron fertilizer mitigated the effects of drought stress and increased the quantity and quality of roselle sepals.
Ali Asghar Ghaderi; Barat Ali Fakheri; Nafiseh Mahdi Nezhad
Abstract
In order to investigate the effects of foliar application of ascorbic acid on the growth indexes and physiological traitsof thyme under drought stress, an experiment was conducted in the split plots based on randomized complete block design with three replications at the Research Farm, Faculty of Agriculture ...
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In order to investigate the effects of foliar application of ascorbic acid on the growth indexes and physiological traitsof thyme under drought stress, an experiment was conducted in the split plots based on randomized complete block design with three replications at the Research Farm, Faculty of Agriculture University of Zabol, Iran. The main factor was drought stress and applied based on the irrigation at 75, 55 and 35% FC and the subplot was foliar application with three levels including distilled water (control), 10 mM and 20 mM ascorbic acid. Main effects of drought stress and foliar application of ascorbic acid were significant (P≤0.01) for all studied traits. The interaction of water stress and foliar application of ascorbic acid was significant only for proline. Applying severe stress compared with control was decreased the total chlorophyll, carotenoid, root and shoot dry weight (29.0, 39.9, 50.5 and 43.0%, respectively), while the leaf proline and the root length were increased (44.2 and 26.6%, respectively). The foliar application of ascorbic acid (20 mM) significantly increased the amounts of photosynthetic pigments, shoot length, root and shoot weight. Simple correlation coefficients of the traits showed a significant and positive relationship between shoot dry weight and other traits, in drought stress and 20 mM foliar application of ascorbic acid conditions. Factor analysis was identified four factors for normal and four factors for severe stress conditions that at overall were explained 98 and 95% of total variation, respectively. In general, it was concluded that photosynthetic pigments and root-related traits would be the important yield related criteria (shoot dry weight), that can be beneficial in the development of thyme with higher performance under stress conditions.