fereshteh darabi; Nosratollah Abbasi; Mohammad Javad Zarea
Abstract
This paper aims at evaluating the effects of putrescine and 24-epibrasinolide on altering the activity of antioxidant enzymes to tolerate drought stress in basil. The plan has been implemented as factorial split plot layout based on a randomized complete block design with three replications in the cropping ...
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This paper aims at evaluating the effects of putrescine and 24-epibrasinolide on altering the activity of antioxidant enzymes to tolerate drought stress in basil. The plan has been implemented as factorial split plot layout based on a randomized complete block design with three replications in the cropping years 2017-2018 and 2018-2019 at the research farm of the Faculty of Agriculture, Ilam University. Experimental treatments include drought stress at three levels (40, 80, and 120 mm evaporation from Class A evaporation pan) as the main plots, putrescine foliar application at three levels (0, 0.5, and 2 (mM) and 24- Epibrassinolid foliar application at three levels (0, 0.5, and 2 μM) as subplots. Results show that the highest amount of proline in 120 mm occurs during the first year of the experiment and the use of putricin (2 mM) and 24-epibrasinolide (0.5 μM) also cause a further increase in proline. The highest amount of catalase has been observed in the 120 mm evaporation treatment and the application of 2 mM putrescine. The interaction of drought stress, putrescine, and 24-epiprasinolide also show that the highest levels of ascorbate peroxidase and superoxide dismutase belong to the treatment of 120 mM where the highest concentrations of putrescine (2 mM) and 24-epibrasinolide (2 μM) is observed. Under optimal irrigation conditions (40 mm), the combined application of lower concentrations of putrescine (0.5 mM) and epibrasinolide (0.5 μM) and under drought stress conditions (80 and 120 mm), higher concentrations of these two substances (2 mM putrescine and 2 μM epibrasinolide) increase the enzyme guaiacol peroxidase. Multiple interactions of year, drought stress, putrescine, and 24-epibrasinolide have had a significant effect on total flavonoids and essential oil percentage of basil. In both experimental years, application of 2 mM putrescine and 2 μM 24-epibrasinolide at all levels of drought stress 120 mm cause a further increase in these two traits which has been greater in the first year than the second one. Concomitant use of 2 mM putrescine and 2 μM epibracinolide due to increased proline synthesis and antioxidant enzymes is the best treatment to reduce the effects of drought stress in basil, indicating a synergistic relation between the two. The substance boosts the growth of basil, increasing the percentage of its essence.
Gholamhasan Movahed; Nima Ahmadi; Ahmad Moieni
Abstract
In order to evaluate the responses of two ecotypes of Damask rose (Rosa damascena) to exogenous ethylene, an experiment was conducted based on a completely randomized design (CRD) at the laboratory of Postharvest Physiology, Tarbiat Modares University, Tehran, Iran. Damsk rose cut stems containg flower ...
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In order to evaluate the responses of two ecotypes of Damask rose (Rosa damascena) to exogenous ethylene, an experiment was conducted based on a completely randomized design (CRD) at the laboratory of Postharvest Physiology, Tarbiat Modares University, Tehran, Iran. Damsk rose cut stems containg flower buds and/or open flowers, single buds, or multiple flowers were exposed to exogenous ethylene for 24 h. Plant organs were placed into hearmatically seald glass chambers, where ethylen was injected, to achieve 0, 1, 2, 3, and 4 µl/l concentrations. Biocehmival characteristics, enzyme activities and morphological characteristics including flower life, contents of anthocyanin, flavonoide, and proline were determind in Kashan and Azaran ecotypes of Damask rose. The lowest psotharvest life was observed at 3 and 4 μl concentration of ethylene and the highest abscission was observed in Azaran ecotypes at a concentration of 4 μl/l of ethylene after four days. Anthocyanin and proline content and catalase activity reduced in both ecotypes studied. For both ecotypes, the lowest content of anthocyanin, proline and the lowest catalase activity (48/77 ΔA 240/mg protein) were observed in those treated with ethylene at 4 µl/l. The highest malondialdehyde (3.63 µmol/g petal fresh weight) was found in Azaran ecotype flowers treated with 4 µl/l ethylene concentration. Decrease of total protein in Kashan flowers (0.32 mg/g fresh petal) was much less than that in Azaran flowers (0.2 mg/g fresh petal). Based on these results, Kashan could be recommended as a tolerant ecotype to be used in breeding programs.