نشریه فیزیولوژی محیطی گیاهی
پیاپی 68 (زمستان 1401)

In order to evaluate the effect of mycorrhizal fungi and phosphorous fertilizer on some root growth traits and activity of enzyme and nonenzyme antioxidants of durum wheat in rainfed conditions, an experiment was carried out as factorial based on a randomized complete block design with three replications at Sarableh Agricultural Research station during growing season 2018-2019. Four cultivars of durum wheat (Dehdasht, Zahab, Savarz and Saji) as the first factor and five levels of fertilizer source (control, 25 and 50 kg.ha-1 P, mycorrhizal fungi (GM), mycorrhizal fungi + 25 kg.ha-1 P) as the second factor were considered. The average comparison results of simple effects indicated that Zahab and Saji cultivars among cultivars and combination treatment of mycorrhizal + 25 kg / ha P and then 50 kg / ha P had the greatest effect on improving the studied traits. The interaction effect of cultivars and fertilizer sources revealed that the combined use of phosphorous fertilizer and mycorrhizal fungi had better results compared to their use alone. So that, the highest fresh and dry weight, length density, and root water content and activity of ascorbate peroxidase, peroxidase, catalase, superoxide dismutase and glutathione synthetase was obtained in combined treatment of mycorrhizal and phosphorus fertilizer at Zahab and Saji cultivars. However, the lowest specific root length, and malondialdehyde and hydrogen peroxide activity were obtained in the same treatment and cultivars. In general, the results showed that inoculation with mycorrhizal fungi in rainfed conditions, especially in Zahab and Saji cultivars, in addition to reducing the application of phosphorus fertilizer can improve root growth characteristics and activity of enzyme and nonenzyme antioxidants. As a result, it reduces the peroxidation of membrane lipids (the decline in production of malondialdehyde and hydrogen peroxide) and increases drought stress tolerance.

Orchids are one of the most famous and important ornamental plants that have a high commercial value. plant tissue culture is one of the most important methods for the plant proliferation. The aim of this study was to determine the best concentration of growth regulators of benzyl amino purine (BAP) and indole butyric acid (IBA) on orchid micro propagation. The flower stem buds of orchid (Phalaenopsis philippinensis) were used as explant. This study was performed as a factorial in a completely randomized design with two factors BAP, IBA and in three replications. In the stem formation section of the first factor BAP at 4 levels (0, 0.5, 1 and 2 mg/l) and IBA at 2 levels (0 and 0.25 mg/l), also in the root formation section the first factor IBA in 4 levels (0, 0.5, 1 and 2 mg/l) and BAP were considered at 2 levels (0 and 0.1 mg/l). The results of this study showed that the highest number of shoot formation was obtained at the concentration of 1 mg/L BAP with 0.25 mg/L IBA which has led to the production of 12.27 shoot per explant. The lowest number of shoot formation was observed in the group control. In the root formation, the highest number of roots (4.33) and also the maximum root length (8.67 cm) were obtained at the concentration of 1 mg/L IBA with 0.1 mg/L BAP. The results also show that the combination of growth regulators together improves the result in comparison with their uses alone. Therefor results generally shows that the plant tissue culture is a suitable and optimal way to propagate orchid species.

Microalgae are diverse group of simple organisms, which are incorporated in pharmaceutical, cosmic, nutritional and biodiesel productions. The amount of growth in microalgae is affected by physical and chemical conditions of growth environment. In commercial scale in order to achieve highest amount of biomass or biodiesel, it is necessary to use culture media with proper combination of materials. Therefore, in this study, effects of different values of temperature, light intensity, lighting period, saltiness and pH were tested by their effect on cell concentration, biomass, lipid and biodiesel production in desmodesmus microalgae. As a result, the best temperature for increase in cell concentration of microalgae was 25 degree of Celsius,  light intensity of 4500 lux, light period of 17 hours, saltiness of 5 ppm and pH of 8. The highest amount of biomass was achieved in light intensity of 3000 lux, 18 hours of lighting, saltiness of 5 ppm and pH of 9. The highest amount of lipid was produced at temperature of 26, light intensity of 4200 lux, lighting period of 16 hours, saltiness of 12 and pH of 9. Finally, the highest amount of biodiesel was produced at temperature of 26, light intensity of 4200, lighting period of  16 hours, saltiness of 11 and pH of 9.

Lead as one of the most expanded metals in environment, effects on human health. Besides, the biological absorption by algae leads to the reduction of heavy metal pollutions in aqueoussolutions. In this study, accumulation and bioabsorption of Pb+ on biochemical characteristics of green alga Entromorpha was investigated. For this purpose, effects of  different concentrations of Pb2+ (0, 50, 100 and 150 µM Pb(SO4)2) in presence of two concentrations of Ca2+ (0 and 0.5 mM CaCl2) was studied in Entromorpha collected on Caspian Sea in two times of 3 and 8 days in random complete design with 4 replications for photosynthetic pigments content, membrane lipid peroxidation and antioxidant enzymes activity. The results indicated a decreasing rate of chlorophylla and b, total chlorophyll and carotenoid and also activity of polyphenoloxidase enzymewith increase of Pb2+ concentration and stress during. In membrane lipid peroxidation assay, malondialdehyde increased significantly by increase of Pb2+concentration. For these traits including chlorophyll, and carotenoid content and also membrane lipid peroxidation assay, effects of Pb2+ stress decreased by using CaCl2 treatment. The results of antioxidant assay showed that catalase, ascorbate peroxidase and peroxidase activities in both 3 and 8 days stress was high without CaCl2 treatment than using it. In general, the results of this study showed that Pb2+causes oxidative stress and biochemical changes in Enteromorpha green algae. Also, the presence of CaCl2 treatment reduces the effects of stress.

Rhamnus pallasii Fisch. & C.A.Mey. is one of the most important species of the Rhamnaceae family, which have widely distributed in Iran. Various factors such as different harvest period, habitat, and climate affect the content of plant secondary metabolites. In this study, phytochemical screening in different morphological parts (fruit, leaf, bark and root) investigated in April, May, July, August and October based on different climatic and phenological conditions. Different parts extracted with water-methanol (80%). The content of phenolics, flavonoids, anthocyanins and phenolic acid compounds of extracts was determined by spectrophotometry method and the antioxidant diphenyl pykryl hydrazyl (DPPH) test was used. The results are significant at the level of 0/05. Methanolic extract of fruit collected in October showed the largest content of total phenolics (583.66 ± 1.02 µg GAE/g DE), anthocyanin (9.06 ± 0.019 mg /l) and phenolic acid (53.87 ± 1.52 µg CAE/g). Also, the highest total flavonoid content was found in methanol extract of leaves in April (514.48±1.77µg QE/g). The fruits exhibited excellent antioxidant properties with IC50 value of 7.52±0.24 µg/ml in October, followed by leaves (8.18±0.29 µg/ml in March), roots (13.50±0.29 µg/ml in March) and barks (14.79±0.37 µg/ml in May). As a result, there is seasonal variation in both the quality and quantity of phenolic compound in different parts of Rhamnus. The phenolic-rich extracts in this study can be effectively used for both research and industrial applications.

Tall fescue is an open pollinated cool season turf grass. Micropropagation and genetic transformation of monocot species have always experienced low genetic transformation efficiency. Therefore, evaluation of explant types and carbon source in media, likely through callus optimization would lead to the genetic transformation improvement which is the goal of this experiment. After surface sterilization of tall fescue seeds, different seed explants with or without embryo, have used to evaluate callus induction ability. Normal sugar, maltose and equal amount of sugar and maltose were also used as a different source of carbon in a completely randomized design with three replications. Finally, embryogenic calli, induced to produce shoots in MS media supplemented with 10 mg/L 2,4-D and 0.05 mg/L BA. The presence of embryo on explant is a necessity for callus induction. Explant without embryos which were cut differently failed to produce callus. The assessment of three carbon source during the course of multiplication under in vitro culture indicated that sucrose and maltose significantly improved total chlorophyll and carotenoid content in regenerated shoots while MS media with equal amount of both aforesaid carbon sources were not effective. The results gained in the present experiment indicated that embryo-contained cross section of seeds and using maltose was the best explant and the best carbon source for callus induction and shoot proliferation respectively.

In order to investigate the effect of the type and concentration of solvent on the amount of extraction of phenolic compounds and antioxidant activity of Crataegus elbursensis leaves, a research was performed in two separate experiments. At first experiment the effect of solvent type (acetone, ethanol, methanol) at three concentrations (50, 80 and 100%) on extracted total phenolics content of C. elbursensis leaf was evaluated. At second experiment antioxidant capacity of produced extract from the best solvent at first experiment with the highest phenolic compounds (methanol 80%) was investigated by two different methods including total antioxidant and Fe reduction capacity. The results of these experiments showed that all three solvents; acetone, ethanol and methanol; in the form of mixture with water have more potential for extracting phenolic compounds toward the pure ones. The highest total phenolic content (118 mg GAE/g DW) was obtained at 80% concentration of all solvents, especially at methanol 80%. The results of evaluating antioxidant activity showed that with increasing the concentration of extract up to 500 µg/mL, antioxidant activity (0.8 mg/mL) was increased. Investigation of Fe reduction capacity indicated that with increasing the concentration of extract up to 800 µg/mL, the amount of absorption of the solvents contain the extract significantly increased. Therefore, according to the results of this study, the leaves of this plant can be used as the source of phenolics and antioxidants in different industries.

Physalis alkekengi is a fruit-bearing plant in Iran. It is very popular due to the nutritional and medicinal properties. The main limitations of its cultivation are short reproductive cycle, fruits susceptibility to pests and limited information about crop management. The use of different micropropagation methods to produce physalis is proposed as practical solution. This study was conducted to evaluate the effect of culture medium and different concentrations of growth regulators on the seeds germination and organogenesis of P. alkekengi by using tissue culture technique as well as providing a suitable protocol for in vitro micropropagation of this plant. Seeds were cultured in 1/2 MS and distilled water with three different stabilizers including Plant Agar, Sand and Filter Paper. Direct regeneration (stem) and indirect regeneration (callusing from stem and leaf explants) were used for regeneration of the physalis. Explants were cultured in different hormone combinations of 6-Benzylaminopurine (BAP in 2 and 3 mg/L) and 2, 4-Dichlorophenoxyacetic acid (2, 4-D) (2 mg/L). The best seed germination medium was 1/2 MS contains plant agar as stabilizer (95%). The best explant for callusing was leaf and the best medium was ½ MS containing 2, 4-D (2 mg/ L). The best regeneration medium was BAP (3 mg / L) + GA3 (0.5 mg / L) on MS 1/2. The best hormone for direct organogenesis of stem was BAP at different concentrations. The best medium for micropropagation was ½ MS containing BAP (3 mg / L) + GA3 (0.5 mg / L) (more than 25 seedlings per explant). Rooting was performed using IBA (150 mg / L) followed by transferring seedlings to ½ MS after one week. Finally, seedlings were easily transferred to the soil and more than 95% of them survived in the greenhouse. These results suggest a protocol for commercial micropropagation of physalis plants.

The present study investigates the effect of sulfur fertilizer on Euphorbia tirucalli L. in pot culture conditions. Plants were cultivated under 10 NPK treatments with sulfur fertilizers (granular or bentonite, with or without thiobacillus and ammonium sulfate each in two concentrations) and one NPK treatment without sulfur, compared with the control in randomized complete blocks for 4 months. Growth parameters including dry and fresh weight of plants, roots, shoots and the ratio of fresh or dry weight of roots to plants as well as protein, chlorophyll, potassium, phosphorus and sulfur content in roots or shoots were measured. NPK fertilizer did not increase phosphorus and potassium uptake but decreased root growth. Addition of sulfur fertilizers except for bentonite sulfur with a concentration of 0.8 g per 80 cm2 of soil with Thiobacillus commercial liquid fertilizer, 250 ml / l, had no effect on recovering the negative effects of NPK and even in most treatments, shoot dry weight and fresh weight decreased. Ammonium sulfate showed the most negative effect on growth parameters. Also, some sulfur treatments had a positive effect on increasing the amount of shoot protein. Chlorophyll a, b and total levels did not show a significant difference between treatments. The effect of sulfur fertilizer on soil pH was different and higher concentration of granular sulfur fertilizer containing Thiobacillus caused a more severe drop. None of the sulfur treatments increased the phosphorus of the shoot and even some treatments had a negative effect on the phosphorus content of the roots as well as the potassium content of the roots and shoots. Only in the treatment of granular sulfur fertilizer with Thiobacillus at lower concentrations, root potassium content increased. Negative effects of sulfur fertilizers were not due to increased sulfur uptake, because the sulfur content changes between treatments were not significantly different.

Regular rice transplanting due to flooding, puddling and leveling has a negative impact on the soil structure, chemical properties and soil microbial activity. Therefore, the study was conducted on the effect of residues of pre-sowing some plants on quantitative and qualitative yield of rice in crop rotation. The experiment was conducted as split plots based on a randomized complete blocks design with four replications in Sari region during 2016 and 2017. Six crop rotation levels including fallow (control), faba bean, clover, perko, buko, and clover + ramtil + phaselia were used as main plots and four levels of nitrogen fertilizer including no consumption (control), 50% less than recommendation amount, recommendation amount based on soil test and 50% more than recommendation amount were 0, 50, 100 and 150 kg/ha of urea source as a sub plots, respectively According to the findings, the highest paddy yield (5147 kg/ha) was obtained for perko pre-sowing with 100 kg urea consumption per hectare, and pre-sowing of buko and multiple of clover + ramtil + phaselia was ranked next with 100 kg urea consumption per hectare. Totally, the highest paddy yield was achieved with pre-sowing of perko, buko, multiple of clover + ramtil + phaselia and clover and nitrogen consumption equals 100 kg urea per hectare. But, in pre-sowing of faba beans and fallow, the highest paddy yield was obtained with nitrogen consumption higher than recommendation amount (150 kg/ha). The highest protein yield was attributed to perko and buko pre-sowing. Moreover, the highest conversion efficiency, amylose content and gel consistency were obtained with perko pre-sowing, and these parameters got ranked next with pre-sowing of buko, clover + ramtil + phaselia, clover and faba bean, respectively.