فصلنامه زیست شناسی گیاهی ایران
سال سیزدهم شماره 4 (پیاپی 50، زمستان 1400)

Iris pseudacorus is a perennial herbaceous belonging to the Iridaceae family. This family consist of about 300 species of flowering plants with lush flowers. This genus spread widely from the temperate to the coastal areas in the Northern Hemisphere. This study was conducted to investigate the effects of silver nanoparticles on morphological and physiological properties of Iris pseudacorus under in vitro conditions based on a completely randomized design with 5 replications. In this experiment, different concentrations of silver nanoparticles (0 as a Control, 5, 10, 20, 40, 80 and 160 mg/l) were used as an experimental treatment. The variance analysis showed that the effect of silver nanoparticles on leaf number, seedling length, mean leaf length, regeneration percentage, leaf area, seedling number, chlorophyll a, chlorophyll b, carotenoid, flavonoid and phenol were significant at 1% probability level. The comparison of data means on morphological traits also showed that the highest leaf number, seedling length, leaf mean length, regeneration percentage, leaf area and the number of seedlings were obtained from silver nanoparticles at the rate of 5 mg/L. The results of the data mean comparison on the total phenol and flavonoid of marsh iris showed that the highest amount of total phenol was observed in 10 mg/L of silver nanoparticles and the highest amount of total flavonoid was in silver nanoparticles at the rate of 40 mg/L. On the other hand, the highest amount of chlorophyll a, chlorophyll b, and carotenoids was obtained at 5 mg / l of silver nanoparticles.
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Lisianthus (Eustoma grandiflorum (Raf) shinn.) is one of the most important and marketable cut flowers in the world and a relatively limited vase life reduces its marketability. The present study's aim was to evaluate the effects of Citrus aurantifolia peel extract, tragacanth gel, hot water treatments and different waters on extending vase life and increasing the qualitative properties of cut flowers of lisianthus. This experiment was conducted based on a completely randomized design with 25 treatments contained three concentrations of C. aurantifolia peel extract (15, 25 and 50 ppm) by three solvents containing distilled water, ethanol and methanol, three levels of tragacanth (1, 2.5 and 5%) in two ways (pulsing and continues), hot water at two temperatures of 35 and 45 °C for 2, 5 and 10 min, tap water, sterilized and non-sterilized distilled water and control without any treatment, each one by three replications. According to the results, the highest vase life (13.66 days) was obtained in 25 and 50 ppm of distilled water C. aurantifolia peel extracts treatments. The lowest stem end bacteria were observed in sterilized distilled water, tap water, 50 ppm of distilled water C. aurantifolia peel extracts, hot water in 35° C for 10 min and 2.5% tragacanth gel. The highest relative water content of petals in 2.5 and 5% of continuous tragacanth gel treatment and 25 ppm of methanolic C. aurantifolia peel extracts were obtained. The maximum activity of catalase and peroxidase was observed in 1% continues tragacanth gel treatment. Generally, using tragacanth gel by pulsing, distilled water and ethanolic extracts could increase lisianthus vase life but using methanolic C. aurantifolia peel extracts is not recommended..

Foliar application is one of the fast and effective methods for providing of plants with nutrition requirements, especially in the critical stages of growth. The aim of this study was to investigate the effect of foliar application of nitrogen, zinc and manganese on leaf element content, yield and quality indices of Bidaneh-Sefid grapevines during one stage before and two stages after bloom. The experiment was factorially (three factors of urea, zinc nano-chelate, and manganese nano-chelate, each at two levels of Zero and 0.08%) based on a randomized complete block design with eight treatments and three replications. According to the results, the highest cluster weight and yield were related to the combined treatment of the second level (0.08%) of urea, zinc nano-chelate, and manganese nano-chelate. Also, the content of soluble solids of the vines treated with the 0.08% urea and 0.08% zinc nano-chelate was higher than in other treatments. The antioxidant capacity of vines treated with all three fertilizers at 0.08% was found to be higher compared to other treatments. The highest flavonoid contents were obtained with 0.08% urea and 0.08% zinc nano-chelate and the highest total phenol contents were related to 0.8% urea in combined with 0.08% manganese nano-chelate. Vines treated with the second level of zinc and manganese fertilizers had higher peroxidase activity. While the highest activity of catalase and ascorbate peroxidase was observed with all three fertilizers at 0.08% foliar application of urea, zinc nano-chelate, and manganese nano-chelate increased the content of nitrogen, zinc and manganese in leaves and fruits. The leaf potassium content of 0.08% manganese nano-chelate sprayed vines was higher alone compared to other treatments. In general, the combined application of these fertilizers (at 0.08%) while improving the leaf elements contents, led to improved berry weight, cluster weight, and yield and also increased quality indicators and enzymatic and non-enzymatic antioxidant capacity of the fruits..

Nowadays, the use of plant growth regulators has increased in improving the resistance of plants to drought stress. Therefore, in order to investigate the effect of salicylic acid on antioxidant enzymes activity and secondary metabolites of Scrophularia striata under water deficit stress, an experiment was conducted as the arrangement in a randomized complete block design with three replications in 2018 at the research greenhouse of Ilam University. Treatments included water deficit stress at four levels (100, 75, 50 and 25% of field capacity) and foliar application with salicylic acid at two levels (0 and 1.5 mM). The results showed that in 75 and 25% of field capacity with salicylic acid, malondialdehyde decreased by 17.81% and 34.04% compared with non-foliar application treatment, respectively. Also, the application of foliar spray reduced the amount of ion leakage under severe drought-stress conditions. Foliar application of salicylic acid increased total phenol content by 20.92, 33.00, 10.84 and 10.19% under 100, 75, 50 and 25%, field capacity, respectively. Under severe drought stress conditions, foliar spray with salicylic acid increased the amount of flavonol and flavonoid compared to the control. With the application of drought stress, catalase enzyme activity increased by 36.09 and 67.65%, respectively, compared to the absence of drought stress. The highest amount of peroxidase activity (1.07 units per mg protein per minute) under 25% of field capacity by application of salicylic acid was observed with the lowest amount of peroxidase activity under 100 per cent of field capacity, respectively. According to the mentioned content, it can be concluded that salicylic acid improved the growth and production of secondary metabolites (Phenol, flavonol and flavonoid) in Scrophularia striata under drought stress and non-stress conditions.

To investigate the effect of selenium and calcium foliar application on antioxidant enzymes activity and some biochemical traits of safflower CV. Goldasht under drought stress, an experiment as a split plot based on a randomized complete block design with three replications was performed in the Agricultural Research Institute of the University of Zabol (Chah Nimeh). Experimental treatments included cut-off irrigation levels based on plant growth stages at three levels (complete irrigation throughout the growing season, R1=irrigation up to terminal bud forms 0.25 inches in diameter and R2=irrigation up to completed flowering as the main factor and spraying at four levels F1= control (pure water), F2= Hamoon Green 1 liter in 10 liters + calcium carbonate, F3= Hamoon Green 1 liter in 20 liters + calcium carbonate and F4= Hamoon Green 1 liter in 30 liters + calcium carbonate was the secondary factor. The highest activity of catalase, ascorbate peroxidase, polyphenol oxidase, and peroxidase enzymes, respectively (35.61, 66.67, 14.08, and 14.33 Umg protein min-1), phenol and flavonoid, respectively. (28.46 and 17.01 mg g-1 FW), soluble carbohydrates (0.957 μmol glucose g-1 FW) and protein (0.021 mg g-1 FW) from irrigation up to terminal bud from 0.25 inches in diameter combined with spraying 1 liter in 10 liters of water + calcium were obtained. Foliar application increased the above traits at any stress level. In general, it seems that spraying 1 liter in 10 liters of water + calcium carbonate can mitigate the harmful effects of drought stress by inducing an antioxidant system and increasing the activity of antioxidant enzymes.

Photosynthesis is one of the most important physiological processes that is negatively affected by salinity stress in plants. Nitric oxide is known as an influential signal molecule in plant responses to environmental stresses. The tomato plant (Lycopersicon esculentum L.) contains a wide range of vitamins and nutrients that are economically and nutritionally important. In the present study, the effects of different levels of salinity stress including 0, 50, 100 and 150 mM NaCl and sodium nitroprusside (SNP) at 0, 100 and 200 μM levels on different photosynthetic parameters were investigated by JIP test. The results of this study showed that salinity stress reduced the efficiency of the oxygen-evolving complex in photosystem II. Salinity reduces the efficiency of light reactions of the photosystem II (φPo/(1-φPo)) and the efficiency index of active reaction centers (γRC/(1-γRC)). Furthermore, the efficiency of biochemical reactions of electron transport (ψo/(1- ψo)) and the efficiency index of reduction of the end electron acceptor in photosystem I (δRo/(1-δRo)) decreased with salinity stress. The results also revealed that salinity stress reduced the overall performance of the photosynthetic apparatus from the beginning of photosystem II to the end of photosystem I (PITotal). Salinity stress reduced photosynthetic pigments, including chlorophyll a, chlorophyll b and total chlorophyll, and a significant increase in total carotenoids, total polyphenolic content and total flavonoid were observed under salinity stress. The use of SNP as a nitric oxide donor mitigated the effects of salinity stress in all the mentioned parameters. The results of this study showed that in the photosynthetic apparatus of the tomato plants, the electron transport chain is the most sensitive point to salinity stress and 100 μM SNP is the most effective concentration to alleviate the effects of salinity stress.