نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Introduction: Marjoram, with its scientific name (Origanum majorana L.), is considered one of the most important and best-selling medicinal and spice plants in Iran and the world. Environmental stresses are one of the important factors in reducing the production of agricultural products in the world. Under natural and agricultural conditions, plants are constantly exposed to various stresses, which is one of the obstacles to the potential production of water deficit, which has a negative effect on the growth and physiological traits of plants. Therefore, one of the possible ways to increase tolerance to drought stress is inoculation with useful microorganisms. These organisms form a colony in the rhizosphere of the plant and increase the growth of the plant through direct and indirect mechanisms. Arbuscular mycorrhizal fungi increase host plant drought tolerance through physiological mechanisms of nutrient uptake and biochemical mechanisms related to hormone synthesis, osmotic regulation, and antioxidant systems. Salicylic acid is a phenolic compound and an essential plant hormone that plays an important role in stress defense and growth regulation. Several studies have investigated the effect of using salicylic acid in plants and have come to the conclusion that salicylic acid causes resistance to a variety of non-biological stresses. The increase in salicylic acid production, along with the decrease in auxin biosynthesis, coordinates plant defense responses, reduces the adverse effects of drought and salinity stress by improving physiological parameters, membrane integrity, and photosynthetic efficiency. For this purpose, an experiment was conducted with the aim of investigating the growth and physiological response of marjoram to the application of mycorrhiza and salicylic acid under drought stress conditions.
Materials and Methods: This experiment was carried out as a split-factorial design in the form of a basic randomized complete block design with three replications. The experimental factors include the main plot of different levels of drought stress (35, 70, and 90% of the field capacity) and the secondary plot with two factors, the first factor including mycorrhizal fungus with two levels (without inoculation and inoculation with Glomus hoi species) and the second factor of concentrations Salicylic acid was different at three levels (zero, 100 and 300 mg/L). One month after planting, salicylic acid treatment was done as foliar spraying. The foliar spraying was repeated twice on the aerial parts of marjoram plants before flowering. The control treatment was considered without foliar spraying and with distilled water.
Results and Discussion: In this study, the traits of plant height, shoot dry weight, shoot fresh weight, number of lateral branches, ion leakage, relative leaf water content, proline, and soluble sugar were investigated. In the 70% field capacity treatment, the application of mycorrhizal fungus and foliar spraying with 300 mg/L salicylic acid increased shoot dry weight by 25.2% and the shoot fresh weight by 6.1% compared to the control (no application). The results showed that ion leakage decreased by 25.5% in the treatment with mycorrhizal fungus application and foliar spraying with 100 mg/L salicylic acid compared to the control. The highest amount of proline was obtained in the 35% field capacity treatment, measuring 2.15 mg/g, which showed an increase of 29.15% compared to the 90% field capacity treatment.
Conclusion: In general, the results of this study indicate that the application of mycorrhiza and foliar spraying with salicylic acid can help improve the growth and performance of marjoram under drought stress conditions. Therefore, it is recommended to use inoculation with the mycorrhizal fungus G. hoi and foliar spraying with a concentration of 300 mg/L salicylic acid for marjoram production in areas with water scarcity.
کلیدواژهها English
