نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Introduction: Peppermint (Mentha piperita L.) from the Lamiaceae family is one of the most widely used medicinal plants. In addition to therapeutic effects, it is used as a flavoring in the production of various foods and medicinal products. Drought stress is one of the most important factors in yield loss and production of field crops, horticulture, and herbs in the world. Several
agronomic and physiological strategies have been implemented to mitigate the negative effects of drought stress and increase plant tolerance to it. Utilizing organic fertilizers is one of the realistic and promising strategies for increasing crop yields under stressful conditions. Few studies have examined the use of these substances as stress modulators in medicinal plants. Humic acid as an organic acid and ascorbate as a powerful antioxidant can be effective to improve the yield in water stress conditions. Therefore, this research was conducted with the aim of investigating the effect of foliar spraying of ascorbic acid and humic acid on some morpho-physiological traits of peppermint under drought stress conditions.
Materials and Methods: In order to evaluate adjusting drought stress by using humic acid and ascorbic acid in peppermint, factorial experiment in a completely randomized design with three replications was conducted. Experimental treatments included drought stress (control and drought stress), humic acid and ascorbic acid (0, 2 and 4 g/l humic acid, 2 and 4 g/l ascorbic acid and 2 g/l humic acid and ascorbic acid). After two month, plant height, leaf number, dry weight of shoot, relative water content (RWC), proline, electrolyte leakage (EL), antocianine, leaf area, chlorophyll a, chlorophyll b, carotenoid, malondialdehyde (MDA), K and P were measured. The obtained data were analyzed using Minitab statistical software. Mean comparisons were conducted using Duncan's multiple range test at a significance level of 5%.
Results and Discussion: The results of the analysis of variance showed that the interaction effect of drought stress and stress modifier was significant for the characteristics of plant height, the number of leaves, chlorophyll a, malondialdehyde and proline. The results showed that drought stress caused a significant decrease in the growth characteristics, plant height, the number of leaves, chlorophyll a and increased malondialdehyde and proline and the application humic acid and ascorbic acid could compensation this damage. The results of the analysis of variance indicated the effect of drought stress and stress modifier was significant for Chlorophyll b, carotenoid, shoot dry weight, P and K, anthocyanin. Chlorophyll b, carotenoid, shoot dry weight, P and K in drought stress were less than control and application of humic acid and the application of ascorbic acid increased these traits. Also, drought stress increased anthocyanin. Also, the results showed that only drought stress effect was significant for leaf area, electrolyte leakage and relative water content. Drought stress conditions increased electrolyte leakage and leaf area and relative water content also decreased under drought stress.
Conclusion: The results of this study showed that the increase in drought stress causes changes in the physiological and morphological traits of peppermint plant. Based on the results obtained in this experiment, it can be stated that although drought stress has negative effects on the physiological and morphological traits of peppermint plant but by using drought stress modifiers (humic acid and ascorbic acid) we can reduce the effects of drought stress on this plant.
کلیدواژهها English
