In this experiment, we studied the effects of drought stress under field conditions on chlorophyll a, chlorophyll b, carotenoids, rubisco large subunit (rbsl) and the activities of antioxidant enzymes in barley at early anthesis, watery ripe, late milk and soft dough stages of two genotypes with different yield (Q13: 1390 Kg/ha and Q20:1582 Kg/ha). The results showed that under oxidative stress chlorophyll b is more sensitive than chlorophyll a. The amount of cartenoids increased at initial time of stress period, but declined with the progress of stress. The amount of rbsl declined during senescence and drought stress. The activity of SOD declined with plant age in both water treatments. However it was more in plants under drought stress of Q13. APX activity declined with age in both water treatments of Q13. There were no significant difference with age in Q20 APX activity. Drought stress triggered increases in antioxidant enzymes activities. We concluded that Q20 has more ability to maintain SOD activity during water deficit stress and APX activity during senescence; therefore it seems that this ability is a key role for increasing the yield of Q20 in compare to Q13.

Biosynthesis of plant PIGMENTS is affected by environmental factors especially light intensity. An expriment was conducted to evaluate the effect of different light intensities on PHOTOSYNTHETIC and non-PHOTOSYNTHETIC PIGMENTS of two rose cultivars including ‘Red One’ and ‘Gulmira’ under greenhouse conditions. In this experiment, the effects of different light intensities including 240, 520 and 640 mmol/m2/s and control with 1200 mmol/m2/s (without application of plastic nets) on the rose cultivars was evaluated under greenhouse conditions. Plastic nets were used to obtain different levels of light intensities. The results showed that PHOTOSYNTHETIC PIGMENTS, chlorophyll and carotenoids, significantly increased in the light intensity of 240 mmol/m2/s vs. control. In this light intensity, antocyanin content was significantly reduced. Reducing light intensity to 240 mmol/m2/s could result in higher chlorophyll as well as carotenoid content without significant changes in flavonoids. Increasing anthocyanin content with increasing light intensity to 1200 mmol/m2/s could be a defense mechanism in plants against toxic levels of light intensities.

Purpose: The aim of this study was to investigate the effect of different vermicomposts and their dosages on chickpea (Cicer arietinum L.) plants in pot culture experiment.Methods: A total of five potting media were prepared containing soil and vermicompost. Soil fortified with 10 and 20 % vermicompost was used as potting media. The fertility status of soil and vermicomposts was quantified. In these potting media, growth, yield and biochemical parameters of chickpea plants were studied up to 90 days.Results: The results showed that the fortification of soil with vermicompost significantly stimulated the chickpea plant growth. The plant height, plant shoot biomass, number of pods and PHOTOSYNTHETIC PIGMENTS were significantly higher in vermicompost-fortified experiments, whereas vermicompost fortification had no significant effect on chickpea seed germination as it was& 100 % in all experiments. Total chlorophyll content in chickpea leaves was in the range of 0.437–1.07 mg/g. Similarly, carotenoid content was minimum in control and maximum in 20 % vermicompost containing potting media.Conclusion: It was concluded that if soil is fortified with appropriate quantities of vermicompost, the chickpea production per unit area could be enhanced significantly.

This study is aimed to evaluate the effects of electromagnetic fields (B=15, 23 mT (AC)), at 50 Hz frequency on Xanthoria parietina and Lepraria lobificans. Chlorophyll a, chlorophyll b, parietin and proline in both species treated with electromagnetic fields 15, 23mT decreased in compare to control. Only chlorophyll a in L. lobificans and xanthophyll in X. parietina in treated with electromagnetic fields 15mT increased in comparison with control. Proline compound in X. parietina increased in treated with electromagnetic fields 23mT in compare to control. The results indicated that different periods of electromagnetic fields cause physiological response in lichens.

In this experiment, the possibility of growth promoting of exogenous salicylic acid during two growth stages on chlorophyll content, yield and yield components of canola plant was investigated. For the purpose of improving above traits, salicylic acid was applied in four concentrations (0, 100, 200 and 400 μ M) during two different growing stages (first time; when temperature was close to 7-10 ° C and second time; when temperature was close to 7-10 ° C at the end of winter) on two canola cultivars (Licord and RGS). The total chlorophyll content was higher when 100 μ M was applied at the second stage of the application on Licord cultivar. Salicylic acid foliar application led to increase in seed yield of both cultivars. The highest plant height, seed weight, and plant biomass were obtained from Licord cultivar. The greatest pod number per plants was observed in Licord which was treated with 100 μ M salicylic acid at the first time while the highest seed number per pod was observed in the former cultivar which was treated with 200 μ M salicylic acid at the first time. In general, our results revealed that salicylic application increased canola growth and productivity of grain yield in both cultivars.

The growth and development of aquatic plants depends to environmental factors such as light, temperature, dissolved oxygen, pH, organic and mineral materials. The purpose of this study was to investigate some physiological responses of Azolla filiculoides Lam. to the pH, electrical conductivity, salinity and dissolved oxygen in different aquatic habitats of Babolsar city. Azolla in green and red colors was collected from the canal around the rice field and rice field in Ojaksar area and Azizak wetland in four replicates and transferred to the laboratory. The study of water parameters showed the pH level among the habitats was slightly but significantly different and the rice field had significantly higher electrical conductivity, salinity and lower soluble oxygen content than the other habitats. The results showed the content of PIGMENTS, protein and peroxidase activity in both Azolla collected from rice field were significantly higher than those of other two habitats. Although the percentage of dry matter, protein, anthocyanin, total nitrogen and phosphorus content of red Azolla in all tree habitats were significantly higher than the green Azolla and it seems the red Azolla has probably a higher ability to absorb the essential elements and synthesize organic compounds than the green Azolla.

The influence of exogenous application of glycine betaine (GlyBet) was examined on PHOTOSYNTHETIC PIGMENTS and ions concentration of safflower under salinity stress conditions. The experiment was performed in a randomized complete block design arranged as a factorial with three replications. Salinity treatments (0, 50, 100, and 150 mM) were applied using sodium chloride (NaCl). GlyBet (0, 10, 30, and 60 mM) sprayed onto leaves of safflower. The results showed that an increase in salinity levels led to an increase in Na+ content and Na+/K+ ratio and a reduce in shoot and root fresh weight, chlorophyll, carotenoid, photosystem II (PS II) activity, K+, and Ca2+ contents. In all stress levels, foliar application of 30 and 60 mM GlyBet led to an increase in chlorophyll a, b and total chlorophyll, carotenoids and PS II activity than control. Also, in all salinity levels, foliar application of GlyBet reduced Na+ content and Na+/K+ ratio of the plants and increased their K+ and Ca2+ contents. These results suggest that the application of 30 and 60 mM GlyBet under salt stress conditions had the largest effect on PHOTOSYNTHETIC PIGMENTS, PS II activity, and K+ and Ca2+ contents of safflower.

In order creation tolerant stimulate signal to drought stress in Peppermint, experimental for factorial in a randomized completely design by three repeat in was conducted researcher greenhouse Faculty Agriculture University of Mohaghegh Ardabili in 2015. Treatments include drought stress in three level (85, 55 and 35 percentage of field capacity) and spraying H2O2 in four level (0, 2. 5, 5 and 7. 5 mM) and characteristics including PHOTOSYNTHETIC PIGMENTS (chlorophyll a, b, total and b/a), PIGMENTS auxiliary (carotenoids, anthocyanin, flavonoids and phenolic compounds) and PIGMENTS fluorescence index (Fv/F0, Fv/Fm, F′ v/F′ m, qP, qNP and ˚ PSII), SPAD and dry weight plant. The result showed, main effect drought stress and H2O2 had effected significant in examined characteristics. Stress cause reduce PHOTOSYNTHETIC PIGMENTS, PIGMENTS auxiliary (except carotenoids), increased fluorescence index (except Fv/F0 and qP) and decrease dry weight plant (25%). Generally can say stress because reduce plant PHOTOSYNTHETIC capacity and reduce production biomass, spraying concentrations of moderate H2O2 also can be used as a signal to improve PHOTOSYNTHETIC systems operate.

In order to investigate the effect of biochar and biological fertilizer on PHOTOSYNTHETIC PIGMENTS, yield, and nutrient content of peppermint (Mentha piperita L. ) an experiment has been conducted as factorial, based on a randomized complete block design in three replications at Sari Agricultural Sciences and Natural Resources University in 2017. The treatments include biochar on two levels (0 and 10 ton ha-1 organic and biological fertilizers on five levels (no fertilizer (F0), vermicompost (10 ton ha ) and -1 ) (F1), Pseudomonas fluorescens (F2), Azotobacter (F3), and Arbuscular mycorrhiza (Glomus mosseae, G. intradicces, and G. etunicatum) (F4)). Results from this study show that the use of biochar increases the chlorophyll a and chlorophyll content by 7. 42% and 9. 71%, respectively. Among fertilizer treatments, the highest amount of chlorophyll belongs to vermicompost (6. 11 μ g. ml-1 ), significantly better than other treatments. In addition, the main effect of biochar and bio-fertilizer have had a significant effect on leaf, stem, and total fresh weight of the plant. Results from comparing mean of fertilizer treatments show that the highest leaf fresh weight, stem fresh weight, and total fresh weight per square meter belong to the treatment of mycorrhiza (306. 08, 361. 15, and 663. 03 g. m-2 respectively). Also, the use of biochar increases the leaf fresh weight, stem fresh weight, and total fresh weight (294. 78, 366. 73, and 661. 46 g. m-2 respectively), compared to the conditions without using it. Based on the results of the comparison of the mean of the main effects, all treatments increase nitrogen content, compared to the control. The highest nitrogen content (1. 83%) is related to Azotobacter treatment, not significantly different from vermicompost, mycorrhiza, and Pseudomonas. Results also suggest that the maximum amount of phosphorus (0. 37%) have been seen in biochar + mycorrhiz and biochar + vermicompost. Therefore, with respect to the production of medicinal plants in the low-input cropping systems, it is recommended to protect the environmental and achieve sustainable agriculture to improve plant growth and photosynthesis of peppermint application of biochar + mycorrhiz along with biochar + vermicompost treatment.

This study was conducted to investigate the effects of different concentrations of ascorbic acid (0, 10 and 20 mM) on growth, fresh and dry weight of basil under different levels of arsenic (0, 40, 80 and 120 mg.kg-1 of soil) in pots. The experiment was factorial based on a randomized complete block design with three replications. It was carried out in greenhouse at the Faculty of Agriculture, University of Zabol. All growth characteristics, fresh and dry weight of shoots and roots and PHOTOSYNTHETIC PIGMENTS of plants treated with arsenic decreased. Application of ascorbic acid, especially at concentration of 20 mM, could increase the amount and activity of PHOTOSYNTHETIC PIGMENTS in basil which resulted, in reducing the negative effects of arsenic and an increase on leaf area, fresh and dry weight of shoot as compared with those of control (non-application of ascorbic acid). Foliar application of ascorbic acid did not have significant effect on plant height, fresh and dry weight of roots and leaves as compared with those of the control.