نشریه فیزیولوژی محیطی گیاهی
پیاپی 66 (تابستان 1401)

The health of plants in green roof conditions depends to a large extent on the supply of water required by plants. The composition of the substrate is effective in maintaining the moisture and making it available to the plant, and one of the solutions to reduce water consumption in the green roof is improving the substrate. In this study, water requirement and some morphophysiological traits of Carpobrotus edulis L. were studied under substrate and humic acid treatment. The research was conducted in green roof box conditions as a factorial experiment based on a randomized complete block design with three replications from May to September 2020 in Mashhad. The first factor was substrate including Substrate 1 (soil 20% + 20% Leica + 20% perlite + mineral pumice + 20% leaf soil), Substrate 2 (substrate 1 + 6% by weight of bentonite), Substrate 3 (substrate 1+ 12% by weight of bentonite), soilless Substrate 4 (27% mineral pumice + 27% Leica + 27% perlite + 20% leaf soil), Substrate 5 (substrate 4 + 6% by weight bentonite), and Substrate 6 (substrate 4+ 12% by weight of bentonite). The second factor was the concentration of humic acid (0, 100, and 200 mg L-1) applied as fertigation every 15 days. Soil-containing substrates performed significantly better than soilless substrates and the highest coverage, root length, and volume of green roof plants were observed in substrate 3 (containing soil and 12% by weight of bentonite). The highest leaf water and chlorophyll contents and the lowest relative saturation deficit, carotenoids, phenols, and leaf carbohydrates were observed in Substrate 3, which show the physiological stability of the plant under stress conditions, was evident in substrate 3. Application of 200 mg/L humic acid was associated with the best growth and physiological performance of plants. A substrate rich in moisture and nutrients, including 20% Soil + 20% Leica + 20% perlite +20% mineral pumice + 12% w bentonite + 200 mg/L humic acid resulted in the plants with optimal water consumption. The presence of soil and mineral superabsorbent (bentonite) in the green roof substrate is especially important in terms of moisture retention, and of course, the supplementary nutrition of plants in the green roof also improves their performance in the green roof.

In order to investigate the effect of mycorrhiza fungi on nutrient uptake of barley in rain fed conditions, a field experiment was carried out in factorial analysis based on randomized complete block design with three replications at the farm station of Sarablah Agricultural Research Center, Ilam during 2019-2020 cropping season. Experimental factors were four barley cultivars (Mahali, Mahoor, Khoram, and Fardan) and fertilizer application including: control (without fertilizer application and mycorrhizal fungi), 50% P chemical fertilizer recommended based on soil test (25 keg/ha), mycorrhizal fungi (Glomus mosseae, Glomus etunicatum, and Rhizophagus irregularis), mycorrhizal fungi along with 50% P chemical fertilizer, and 100% P chemical fertilizer as recommended. Results indicated that interaction between cultivar and fertilizer sources had significant effect on nitrogen, phosphorus, potassium, magnesium, iron, copper, and manganese. Interaction of Fardan cultivar and mycorrhizal fungi + 50% phosphorus fertilizer resulted in the highest nitrogen (11.1%), phosphorus (1.19%), potassium (3.92%), magnesium (0.292%), iron (136.5 mg.kg-1) manganese (65.8 mg.kg-1), and copper (65.71 mg.kg-1) in leaves. According to the obtained results, in the rain fed conditions, the new cultivar Fardan is recommended with mycorrhizal fungi along with 50% phosphorus fertilizer given the high concentration of high macro elements (nitrogen, phosphorus, potassium and magnesium) and micro elements (iron, manganese, and copper) and the role of these elements in plant growth and photosynthesis

Association analysis of 105 bread wheat (Triticum aestivum L.) genotypes was carried out using 12 SSR markers. For this purpose, wheat seeds were planted in pots in a randomized complete block design with three replications under normal (10 mM NaCl) and saline (120 mM NaCl) conditions and the activity of catalase (CAT), ascorbate peroxidase (APX), and total protein contents were measured. The results of combined analysis of variance showed that the activity of catalase, ascorbate peroxidase, and total protein contents were significantly different in the bread wheat cultivars under study. The results of multiple regression analysis showed that gwm67b and gwm282d markers under salinity conditions were more correlated with catalase activity in the studied species. Also, gwm291a, wmc73a, and barc124a markers were the most effective markers in association with APX enzyme. Analysis of the population structure and the resulting plot showed that the K Index and the Average Likelihood Logarithm had the highest value at K =2 (57.38), thus the population under study has most probably 2 subpopulations. Tassel analysis of SSR markers under normal irrigation and salinity irrigation conditions obtained 54 loci related to the traits under study in control condition and 61 loci in salinity condition based on the general linear model (GLM) and also 35 related loci in control condition and 20 loci in salinity condition based on the mixed linear model (MLM)

In order to investigate the effect of using superabsorbent polymer on photosynthetic traits, chlorophyll content, and chlorophyll fluorescence indices of beans (Phaseolus vulgaris L.) under drought stress, an experiment was conducted using a split-plot arrangement in randomized complete block design with 4 replications in the Research Field of Islamic Azad University, Kaleibar Branch, Iran in crop year 2018. Experimental treatments included irrigation intervals in the main plots (after 70, 140, and 210 mm water evaporation from class A evaporation pan) and application of different amounts of superabsorbent polymer (0, 75, and 150 Kg.ha-1) in sub plots. Results showed that the main effect of drought stress and superabsorbent were significantly different in most measured traits (p≤0.01). Interaction between drought stress and superabsorbent was significant only in the stomatal conductance, cell membrane stability, and chlorophyll index. Mean comparison results showed that severe drought stress significantly reduced maximum photochemical efficiency of PSII, maximal fluorescence (Fm), chlorophyll content, transpiration rate, CO2 concentration under stomatal chamber, and photosynthesis rate, indicating the role of stomatal factors in reducing photosynthesis under stress conditions. The use of superabsorbent significantly increased photosynthetic rate, stomatal conductance, transpiration rate, cell membrane stability, maximum photochemical efficiency of PSII, maximal fluorescence (Fm), minimum fluorescence (F0) and chlorophyll index while CO2 concentration under stomatal chamber reduced. The highest records of most measured traits were observed in 75 Kg.ha-1 superabsorbent polymer treatment. In general, it was concluded that superabsorbent improves photosynthetic properties, the maximum photochemical efficiency of PSII, and chlorophyll content of beans under drought stress.

The genus Taverniera from Fabaceae family is one of the most valuable plant species compatible with desert areas, which is very important in terms of forage production, soil conservation, and medicinal properties. The current research was carried out to investigate the effect of different treatments on seed dormancy breaking and germination stimulation of taverniera cuneifolia. Dormancy breaking treatments included H2SO4 (50% and 75% for 5 and 10 min.), scarification with sandpaper (for 1 min.), KNO3 (0.1% and 0.2% for 24 and 48 h.), hot water (70 and 90 ℃, each for 15 min.) and hydropriming (for 36 h.) with three replications. Results revealed that H2SO4 (75% for 5 min.) led to the highest germination speed and seed vigor index and the lowest mean germination time. Also, maximum germination percentage (78%) was observed under this treatment. Scarification with sandpaper also exhibited considerable effect on the germination percentage (76%). Thus, H2SO4 (75% for 5 min.) and scarification with sandpaper would be suggested as the most efficient treatments to break seed dormancy of Taverniera cuneifolia.

This study was performed to investigate the effect of drought stress and salicylic acid on quantitative and qualitative yield and biochemical and physiological properties of stevia. An experiment was carried out based on a split plot design and randomized complete blocks with 3 replications in a research farm in Sarableh, Ilam during 2020-2021. Drought stress in 3 levels (control or 100% of field capacity, 75% of field capacity, and 50% of field capacity) and salicylic acid treatment in 2 levels (non-consumption and foliar application with a concentration of 1 mM) were applied. Plant height, number of periphery shoots, dry weight of stems and leaves, total dry matter yield, extractable sugars, and protein, proline, total chlorophyll, stevioside, glycoside, rebaudioside, and phenolic compound contents were assayed in the study. Findings showed that the highest total dry matter yield were obtained in irrigation control and salicylic acid consumption (77.2 g per plant), showing 34% increase compared to the lowest total dry matter yield obtained under 50% of field capacity irrigation and no salicylic acid consumption 34%. Also, in all drought stress treatments, applying salicylic acid improved total dry matter yield. In the treatment with no drought stress, the lowest sugar contents per plant were observed and in the treatment with salicylic acid the glucoside contents were more than the control. In general, drought stress reduced the amount of sugar and other growth traits of stevia plants. Applying salicylic acid in addition to improving the quantitative and qualitative traits of the stevia, improved the plant’s yield under various levels of drought stress, which is very important

Drought stress is the most common abiotic stress that has the most negative effect on plant growth and production Polyamines are plant growth regulators that increase plant resistance to environmental stresses, including drought stress. The aim of this study was to investigate the effect of foliar application of spermidine on reducing the effects of drought stress on marigold (Calendula officinalis L.). For this purpose, foliar application of spermidine (0, 50, and 100 mg/l) was considered at different levels of drought stress (control, 25, 50, and 75% of field capacity) in a factorial experiment based on a completely randomized design with 3 replications in 2018 in a greenhouse located in northern Iran. The foliar application was applied at three stages with intervals of about 20 days including six visible leaves, complete tillering, and emergence of the first bud. Results showed that drought stress and foliar application of spermidine had a significant effect on the evaluated traits. The highest fresh and dry weight of shoots, number of flowers, and total chlorophyll contents were observed in the treatment with 75% of field capacity and spermidine 50 mg/l and the highest fresh and dry weight of roots and flowers on the plant were recorded in the treatment with 100% of field capacity and spermidine 100 mg/l. Also, the highest root length, plant height, total antioxidant activity (DPPH), rutin and quercetin were observed in the treatment with 75% of field capacity and spermidine 100 mg/l and the highest proline and polyphenol oxidase activity was observed in the treatment with 25% of field capacity. Therefore, according to the results of this study, foliar application of spermidine 100 mg/l with an irrigation level of 75% of field capacity is recommended for marigold.

In order to investigate the effect of foliar application of ascorbic acid on the activity of antioxidant enzymes in mung bean (Vigna radiate L.) under water-deficit stress, a field trial was performed in a split-plot design arranged in completely randomized block design with three replications in the Education and Research Center of Natural Resources Safiabad, Dezful during the two cultivation years (2017 and 2018). Four levels of water-deficit stress treatments were considered in the main plots (25, 50, 75, and 100% of plant water requirement) and combined treatment of foliar application of ascorbic acid in three levels (control, 10, and 20 mM) and genotype including Omidbakhsh VC6173 and Partow cultivars as subplots. The results of mean comparison showed that the highest levels of superoxide dismutase and ascorbate peroxidase were observed in water-deficit stress of 25% water requirement and no foliar application of ascorbic acid. The highest activity of catalase enzyme was observed under water-deficit stress of 50% water requirement and no foliar application of ascorbic acid. Also, the highest activity of guaiacol peroxidase enzyme was observed in Omidbakhsh VC6173 cultivar under water-deficit stress of 25% water requirement and no foliar application of ascorbic acid. The highest glutathione peroxidase activity was observed in VC6173 cultivar under water-deficit stress of 75% water requirement and 10 mM foliar application of ascorbic acid. Results showed that dehydration stress significantly increased the activity of antioxidant enzymes while foliar application of ascorbic acid due to its antioxidant properties reduced the effects of stress and thus reducing the activity of antioxidant enzymes

To evaluate the effects of different concentrations of salicylic acid and nano iron chelate on the mucilage and carbohydrate values as well as some morpho-physiological traits of Viola aodorata L. species, a factorial experiment was defined based on randomized complete block design with three replications. After planting the seeds in pots, experimental treatments included foliar application of salicylic acid at three levels (0, 0.75 and 1.5 mg / L) as well as nano iron chelate at two levels (0 and 1 g / L) was applied at seedling stage. According to the results, the highest amounts of carotenoid, chlorophyll a, chlorophyll b as well as the total chlorophyll, protein and catalase were observed in specimen treated with 1.5 mg / L salicylic acid. Moreover, the highest amounts of sodium, copper, mucilage and fresh plant weight were detected in specimen treated with 1g / L iron nano chelate. The results also demonstrated that the highest amount of carbohydrate was found  in specimen treated with 1.5 mg / L salicylic acid and 1 g / L nano-iron chelate. In this investigation, the foliar application of salicylic acid (1.5 mg / L) and iron nano chelate (1 g / L) led to a 12 and 19 percent increase in the plant height compared to the untreated sample, respectively. Therefore, treatment with salicylic acid and nano-iron chelate could be recommended to increase the growth and medicinal properties of this plant species.

Alfalfa is one of the most important forage corps in the world. The Medicago plant is a major genus from the fabaceae.High concentration of heavy metals in soil is one of the most important problems in the environment . Cadmium is a heavy metal that can cause oxidative stress in plant cells. In this research effects of different concentrations of cadmium (0 , 25 and 50 µM) and gibberellic acid (0 , 5 and 10 µM) were investigated on certain physiological parameters in Medicago sativa L. Alfalfa seeds were sterilized and cultured in pots containing sand which were irrigated with Hoagland nutrient solution. plants were treated with cadmium chloride and gibberellin 22 - old day.after twenty two days Plants were harvested to assay some physiological parameters. All treatments were conducted with four replications. Experiment results showed that increasing cadmium chloride concentration in Hoagland nutrient solution, decreased growth parameters and pigment contents and GPX activity.But , but proline contents, SOD and CAT activties in roots and leaves of plants increased. by additionof gibberellin concentrations. . It is concluded that gibberellic acid could alleviate the adverse effects of stress cadmium chloride in Medicago sativa L.