نشریه فیزیولوژی محیطی گیاهی
پیاپی 71 (پاییز 1402)

Water stress is one of the most important abiotic stresses that harms the growth of plants in arid and semi-arid regions. Plant traits reflect their response and adaptation to environmental changes, which play an essential role in predicting various environmental effects on plants and plant processes. In order to investigate the effect of biochar on the morpho-physiological characteristics of the species (Kochia prostrata L.) in water shortage conditions, a factorial experiment was conducted in the form of a completely randomized design with three replications in greenhouse condition. Drought stress treatments included four levels (25, 50, 75, and 100% of the field capacity), and biochar treatment included four levels (control, 5 g, 15 g, and 30 g). Morphological traits (plant height, root length, aerial biomass weight, and root biomass weight) and physiological traits (photosynthesis, plant water potential, stomatal conductance, and transpiration) of the target species were assayed under drought and biochar treatments. Results showed that the interaction effect of drought stress and biochar on all characteristics except for plant height was significant. Moreover, the main effect of drought stress on all characteristics except for photosynthesis and water potential and also the main effect of biochar on all characteristics except for root length) were significant. The treatment with 30 grams of biochar caused an increase in morphological characteristics (root length, plant height, and plant biomass) by 22%, 36%, and 50%, respectively, compared to the control; this treatment also caused a significant increase in photosynthesis and stomatal conductance by 107% and 32%, respectively compared to control. According to the findings, the biochar treatment of 15 grams resulted in a better performance and can be suitable to increase the efficiency in the species under study. The results obtained from this research can be an essential step toward the practical use of biochar in restoration and improvement of rangelands.

In order to investigate the effect of mycorrhizal fungus on the growth and yield of autumn chickpeas under supplementary irrigation conditions, an experiment was conducted as a split plot in the form of randomized complete blocks with three replications in the 2016 crop year in Ilam. Experimental treatments include supplementary irrigation with three levels of control or rainfed, once irrigation (flowering time), twice irrigation (flowering time and ten days after flowering) in main plots and fertilizer with four levels of control, mycorrhiza, chemical fertilizer (nitrogen and phosphorus) And mycorrhiza with chemical fertilizers (nitrogen and phosphorus) were considered in subplots. The results showed that the effect of fertilizer interaction and supplementary irrigation on pod number per plant, grain yield, biological yield, shoot and root nitrogen was significant. The average grain yield in mycorrhiza fertilizer treatment and double irrigation compared to chemical fertilizer treatment (nitrogen and phosphorus) and rainfed conditions showed an increase of about 59%. In general, the results showed that double supplementary irrigation with the use of chemical fertilizers and mycorrhiza increases the reproductive growth of the plant. This increase is due to increased photosynthesis and consequently more photosynthetic material, which increases the yield components and improves the yield of chickpeas, so the use of this management method to achieve optimal production is recommended.

In order to investigate the effect of humic acidic and cycocel on yield, yield components, and remobilization of wheat photosynthetic materials under end-of-the-season drought stress conditions, a split factorial experiment was conducted based on a randomized complete block design with three replications in field in Ahvaz during two years (2017-19). The main factor of drought stress at the end of the season with two levels of normal irrigation and cessation of irrigation in the post-pollination stage, cycocel with three levels of water as a control, 1.5 g/l, and 3 g/l, and humic acid with three levels of non-foliar application (water as control), 2 liters per hectare, and 4 liters per hectare were factorial sub-factors. Results showed that the interaction of end-of-the-season drought stress and cycocel on grain yield and number of grains per spike was significant. The highest grain yield (4840.5 kg ha-1) was obtained by applying 3 g/l cycocel under normal irrigation conditions, which did not show a statistically significant difference from the application of 3 g/l cycocel under drought stress at the end of the season. Application of humic acid had a positive and significant effect on all test traits. The highest grain yield, number of grains per spike, and 1000-grain weight were obtained from the application of 3 liters per hectare of humic acid under normal irrigation conditions. Under end-of-the season drought stress, the current photosynthesis and the share of current photosynthesis decreased by 29% and 10%, respectively while remobilization and contribution of remobilization increased by 16% and 34%, respectively. In general, to increase the rate of grain yield under optimal conditions and reduce the drop in stress conditions, growth regulators such as cycocel by a concentration of 3 g/l and organic acid fertilizer by the concentration of 4 liters per hectare are recommended.

Drought is one of the most important factors in reducing plant yield, and understand the ways to deal with drought stress is very important. This experiment was performed to study the effect of foliar application of organic growth stimulants (Hamoon Green ®) on some physiological traits, yield, and oil content of Goldasht safflower cultivar under different levels of drought stress in the form of split plots in a randomized complete block design in the Research Farm No.1 of Zabol University located in Jazinak, Sistan Dam, in Zabol with three replications. The main factor of drought stress at 3 levels included full irrigation, irrigation up to the main stem flowering stage, and irrigation up to full flowering stage. The secondary factor was plant growth regulator at four levels including control, 8, 10, and 12 liters per hectare. Measured characteristics included plant height, number of leaves, number of heads per plant, 1000-seed weight, petal weight, stem diameter, seed protein percentage, grain yield, seed oil percentage, proline, catalase and peroxidase. The interaction of growth stimulant levels and drought stress was significant only on plant height, stem diameter, oil percentage, and proline concentration. The maximum plant height (64 cm) and percentage of oil (32.7%) were obtained from non-stress and foliar application of 12 liters of growth stimulant; the highest proline concentration was recorded under foliar application of 12 liters growth regulator the flowering stage of the main stem (0.38%); the maximum stem grain yield (1127.08 kg ha-1) was recorded with the plants sprayed with 12 liters of growth stimulant. In general, foliar application of growth stimulants moderated the negative effects of drought stress on some traits of safflower plant and improved grain yield by 36.6%. Also, irrigation up to the flowering stage of the main stem can lead to the yield similar to full irrigation.

This study aimed to investigate the effect of the exogenous application of melatonin treatment on the activity of enzymes and compounds effective in the shelf life of tomato fruit during storage. Melatonin has been implicated in various aspects of cell growth and development and has recently been shown to play a role in protecting cells from biotic and abiotic stress. In this study, tomato fruit was immersed with 100 μM L-1 melatonin as a treatment and distilled water as a control group for 15 minutes, then kept at 4±° C for 4 weeks. The results showed that melatonin treatment by reducing the activity of superoxide dismutase and catalase enzymes was able to reduce the content of free radicals’ superoxide and hydrogen peroxide and thus the content of flavonoids, total phenol, vitamin C, and glucosinolate. These results showed that melatonin treatment can be effective by increasing the content of cell protective compounds and also by affecting the activity of antioxidant enzymes to increase the post-harvest life of tomato fruit.

Blackberries produce several types of phytochemicals beneficial to human health and wild blackberries are richer than cultivated ones. Climatic conditions have a great impact on plants in various ways. In this experiment, wild blackberries from two regions in the west and east of Golestan province (Bandar-e-Gaz and Minoodasht regions), in each region from two places (plain and foothills) and two different seasons of fruit ripening (late spring and late summer) were sampled and studied for morphological and phytochemical traits. The results showed that the region and place of growth and harvest season had a great impact on the morphological and phytochemical traits of wild blackberry fruit. Blackberries harvested from Bandar-e-Gaz had higher inflorescence length and width than blackberries of Minoodasht. There was a significant difference between spring and summer blackberries respecting the number of fruits per inflorescence and the number of drupelets per fruit. There was also a significant difference between spring and summer blackberries in all fruit traits, including fruit length, diameter, and weight. The fruits of Bandar-e-Gaz blackberries were more spherical (L/D 0.97) and had a higher fresh weight (1.23 g). The results also showed a significant difference between the blackberries of the two regions and between the two harvest seasons in total acidity, ascorbic acid, and pH. Spring fruits harvested in Minoodasht showed the highest amounts of acidity (5.52 mg/100mg) and total soluble solids (°Brix) and the lowest amount of pH (2.28). Blackberries harvested in Minoodasht region had more total anthocyanin (1.245 mg/100ml) but less total flavonoids (0.471 mg/100ml) and total phenols (0.36 mg/100ml) than blackberries harvested in Bandar-e-Gaz region. There was a significant difference between spring and summer fruits of both regions respecting the above-mentioned traits as well as antioxidant activity; spring fruits showed higher values ​​in most of them. It seems that the climatic conditions of the region are more suitable for the cultivation of spring blackberry cultivars and the fruits obtained from these cultivars and genotypes have higher nutritional and medicinal properties.

In order to investigate the effect of biochar fertilizer and humic acid foliar application on quantitative and qualitative characteristics of Roselle (Hibiscus sabdariffa) a split plots experiment in a randomized complete block design was performed with three replications in the Research Field of Islamic Azad University, Arak Branch during 2017-2018 and 2018-2019. Experimental factors included 3 levels of biochar (non-consumption or control, 4 tons ha-1, and 8 tons ha-1) and the second factor of foliar spraying of humic acid 82% at 4 levels (non-consumption or control, 100 mg/l, 200 mg/l, and 300 mg/l. Interaction of biochar and humic significantly affected fruit yield. In the treatment with 8 t/ha biochar and 200 mg/l humic acid, the fresh weight of shoots was 465.1 g plant, showing an increase by 32% compared to the minimum value obtained from fertilizer control. At different levels of humic acid, consumption of 8 tons per hectare biochar always increased fruit yield compared to non-biochar treatment and consumption of 4 tons per hectare biochar. The interaction of biochar and humic acid on color intensity was significant. In the combined treatment of 8 tons per hectare of biochar and 100/l of humic acid, a red index of 14.67 was obtained. At different levels of humic acid, consumption of 8 tons per hectare biochar increased the red color index. Considering the fact that the intensity of red color in Roselle indicates the quality of the product, the consumption of 300 mg per liter humic acid and 8 tons per hectare biochar increased this trait, improving its functional traits.

The objective of this study was to evaluate the effect of different concentrations of calcium nanoparticle and putrescine on some physiological traits of the medicinal plant, stevia, under salt stress. In this regard, the experiment was performed based on a factorial completely randomized design with three replications. The experimental treatments contained three levels of calcium nanoparticle (0, 75, and 150 ppm), two levels of putrescine (0 and 1 mM), and three levels of salt (0, 75, 150 mM). Based on analysis of variance results, the simple effect of each treatment as salt stress, calcium nanoparticle, and putrescine was significant at P≤0.05; however, their interaction effect was not significant. Results also showed that salt stress (150 mM) resulted in the reduction of chlorophyll a (0.21), chlorophyll b (0.47), and total chlorophyll (0.68 mg/g dry weight) compared to the control while, an increase in carotenoid content (0.10) was observed under 150 mM salinity. Also, the photosynthetic pigments content increased under 150 ppm calcium nanoparticle and 1 mM of putrescine. Considering antioxidant enzymes, the treatment with 150 mM salt increased catalase enzyme as 1.69 and as 5.02 g/wet weight. In addition, the effect of putrescine led to the increase of catalase and peroxidase by 2.18 and 4.46 g/wet weight of leaves, respectively. Moreover, the treatment with 150 ppm calcium nanoparticles resulted in increases in catalase and peroxidase contents by 1.87 and 4.84 g/wet weight of leaves, respectively. The most appropriate concentrations of putrescine and calcium nanoparticles were 1 mM and 150 ppm, respectively which are recommended for assessment of other physiological and biochemical properties of stevia.

Olive (Olea europaea) is a tree species whose seedling grows slowly and the propagation by seed is time consuming and increases the probability of genetic alterations. The most appropriate method to propagate olive is the use of shoot cutting as asexual propagation; however, semi-hardwood olive cutting is hard-rooting. The purpose of the current research was to facilitate rooting on shoot cutting of olive cv. Mari using the concentrations of 2, 3, and 4 g l−1 of indolebutyric acid (IBA) and naphthaleneacetic acid (NAA), singularly and in combination with each other. Used cultivation bed was sand. The research was done as a factorial based on a randomized complete block design with three replications. Rooting percentage, root number, root length, and root fresh and dry weights were measured. Based on the results of this experiment the highest percentage of rooting (83.30%), maximum root number (17.09), longest root (22.67 cm), and dry (2.30 g) weight were obtained in cuttings treated with 3 g l−1 NAA together with 3 g l−1 IBA. The highest fresh weight (4.83 g) was obtained in cuttings treated with 4 g l−1 NAA together with 3 g l−1 IBA. The lowest percentage of rooting, maximum root number, shortest root, and lowest fresh and dry weights were obtained in control.

In order to investigate the effects of soil salinity, plant density and planting date on quantitative and qualitative yield of forage mustard forage, an experiment was conducted in 2016 at Gorgan Nemoone Farm Research Station as a split split plot in a randomized complete block with three replications. Main factor of soil salinity (2 and 10 dS/m), sub-factor of planting date (6 November, 21 November, 6 December, 21 December and 5 January) and sub sub-factor of plant density at three levels (208000, 277000 and 416000 plants Per hectare) was considered. The results showed the interactions of environment × planting date on all studied traits including fresh weight, dry weight, percentage of leaf protein, percentage of stem protein, percentage of pod protein, percentage of total protein, protein yield, percentage of leaf fibers, percentage of stem fibers, percentage of Pod fibers, percentage of total fibers, fiber yield and leaf proline concentration were significant. The interaction effect of environment × planting density was also significant on all the mentioned traits except leaf protein percentage and leaf proline concentration. Also, the interaction effect of planting date and planting density was not significant only on stem protein percentage and leaf proline concentration. In conclusion, it can be said that the cultivation of forage mustard on November 6 and 208000 plants per hectare will produce the highest fresh and dry weight of forage and protein yield, as well as the lowest amount of fiber.

Pomegranate is one of the most important horticultural products that cultivated in many tropical and subtropical parts of the world. Meanwhile, in some pomegranate orchards, salinity stress is one of the abiotic stresses that harm agricultural crops such as pomegranate production by reducing productivity. This research aims to compare growth characteristics between selected genotypes including 1- Chah Afzal 2- Vahshi Babolsar, 3- Narak Lasjerd Semnan 4- Poost Siahe Yazd, 5- Malase Yazdi, 6- Rababe Neyriz, under salinity stress, in a randomized complete block design with three replicaions at Chah Afzal research station of Ardakan city. During the whole experiment, the trees were irrigated with saline water with salinity of 9 ± 0.5 dS/m every 12 days. Based on the results of this research and considering the lowest amount of ion leakage, the highest content of relative humidity and potassium, the high amount of total chlorophyll, carotenoid and leaf surface ratio, the lowest sodium to potassium ratio and necrosis percentage Chah Afzal genotype showed very good resistance to salinity conditions, followed by Poost Siahe Yazd, Vahshi Babolsar, Narak Lasjerd, Malase Yazdi and finally Rababe Neyriz were highly sensitive to salinity. According to the results of cluster analysis, the highest similarity between genotypes based on the parameters mentioned above was between the Narak Lasjerd and Malase Yazdi. The highest difference between Chah Afzal genotype and other genotypes was registered. This shows a significant difference in the superiority of Chah Afzal genotype over other genotypes in total traits. Therefore, due to the compatibility and proper growth of these genotypes in saline conditions, it is suggested that they could be used as a rootstock and the cvs. Malase Yazdi and Rababe Neyriz, which also produced flowers and fruits in saline conditions, can be grafted on them.