بررسی تاثیر پوتریسین و ۲۴- اپی براسینولید بر فعالیت آنزیم های ضداکسنده گیاه ریحان تحت شرایط تنش خشکی

This paper aims at evaluating the effects of putrescine and ۲۴-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 ۲۰۱۷-۲۰۱۸ and ۲۰۱۸-۲۰۱۹ at the research farm of the Faculty of Agriculture, Ilam University. Experimental treatments include drought stress at three levels (۴۰, ۸۰, and ۱۲۰ mm evaporation from Class A evaporation pan) as the main plots, putrescine foliar application at three levels (۰, ۰.۵, and ۲ (mM) and ۲۴- Epibrassinolid foliar application at three levels (۰, ۰.۵, and ۲ μM) as subplots. Results show that the highest amount of proline in ۱۲۰ mm occurs during the first year of the experiment and the use of putricin (۲ mM) and ۲۴-epibrasinolide (۰.۵ μM) also cause a further increase in proline. The highest amount of catalase has been observed in the ۱۲۰ mm evaporation treatment and the application of ۲ mM putrescine. The interaction of drought stress, putrescine, and ۲۴-epiprasinolide also show that the highest levels of ascorbate peroxidase and superoxide dismutase belong to the treatment of ۱۲۰ mM where the highest concentrations of putrescine (۲ mM) and ۲۴-epibrasinolide (۲ μM) is observed. Under optimal irrigation conditions (۴۰ mm), the combined application of lower concentrations of putrescine (۰.۵ mM) and epibrasinolide (۰.۵ μM) and under drought stress conditions (۸۰ and ۱۲۰ mm), higher concentrations of these two substances (۲ mM putrescine and ۲ μM epibrasinolide) increase the enzyme guaiacol peroxidase. Multiple interactions of year, drought stress, putrescine, and ۲۴-epibrasinolide have had a significant effect on total flavonoids and essential oil percentage of basil. In both experimental years, application of ۲ mM putrescine and ۲ μM ۲۴-epibrasinolide at all levels of drought stress ۱۲۰ mm cause a further increase in these two traits which has been greater in the first year than the second one. Concomitant use of ۲ mM putrescine and ۲ 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.

Keywords:

پوتریسین , کاتالاز , درصد اسانس , پرولین , اپی براسینولید.ریحان