نوع مقاله : پژوهشی
نویسندگان
1 دانشآموخته کارشناسی ارشد، گروه علوم باغبانی و فضای سبز، دانشکده کشاورزی، دانشگاه زابل، زابل، ایران
2 استادیار، گروه علوم باغبانی، دانشکده کشاورزی، دانشگاه زابل، زابل، ایران
3 استادیار، گروه علوم باغبانی و فضای سبز، دانشکده کشاورزی، دانشگاه زابل، زابل، ایران
4 گروه زراعت و اصلاح نباتات، پژوهشکده کشاورزی، پژوهشگاه زابل، زابل، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objectives: Abiotic stresses are one of the main constraints in agricultural development, leading to significant yield reduction. High temperature stress is one of the most destructive abiotic stresses that affects all physiological and biochemical processes of the plant, reducing growth and crop quality, and if the stress persists, and may eventually lead to plant death if the stress persists. In recent years, researchers have proposed various strategies to increase plant tolerance to high temperature stress; one of these strategies is the exogenousapplication of phytohormones. The present study aimed to investigate the effect of brassinosteroid and methyl jasmonate under high temperature stress conditions on the morphological and biochemical characteristics of Vicuna pepper.
Materials and Methods: The long green pepper (Capsicum annuum) is a herbaceous, annual plant from the Solanaceae family that has significant anti-inflammatory and antibacterial properties due to its high content of alkaloids such as capsaicin. In order to investigate the effect of brassinosteroid and methyl jasmonate on modulating the effect of high temperature stress in Vicuna pepper seedlings, an experiment was conducted in 2024 in the greenhouse at Research Institute of Zabol in a completely randomized design with three replications. The experimental treatments included temperature of 25°C, temperature of 40°C, brassinosteroid foliar application and temperature of 40°C, methyl jasmonate foliar application and temperature of 40°C, combined foliar application of brassinosteroid and methyl jasmonate and temperature of 40°C. In this study, the traits of plant height, number of leaves, fresh and dry weight of shoots, concentration of total chlorophyll, carotenoids, content of hydrogen peroxide, proline, activity of antioxidant enzymes, were evaluated.
Results: The results showed that the highest plant height (15.33 cm), number of leaves (8.33), fresh fruit weight (13.91 g), dry fruit weight (8.5 g), total chlorophyll content (14.2 mg/g F.W.), relative leaf water content (56%) and membrane stability index (22%) were obtained in the conditions of plant growth at 25 °C (control). The highest carotenoid content (0.17 mg/g F.W.) and hydrogen peroxide (0.46 μmol/g fresh weight) were obtained in the temperature stress treatment of 40 °C. Spraying pepper plants under heat stress conditions with brassinosteroid + methyl jasmonate produced the highest number of fruits (10), the highest fresh weight (35 g) and the highest yield (170 g / plant). The highest proline content (52 μg/g F.W.) was obtained under foliar application of methyl jasmonate under heat stress conditions. The combination of brassinosteroid and methyl jasmonate at 40°C also led to a 1.71, 1.52, 3.25 and 1.67 times increase in the activities of catalase, peroxidase, ascorbate peroxidase and superoxide dismutase enzymes compared to the absence of these hormones under high temperature stress conditions.
Conclusion: Overall, the results showed that the combination of brassinosteroid and methyl jasmonate improved the tolerance to high temperature stress in Vicuna pepper seedlings by improving the activity of antioxidant enzymes, reducing the production of hydrogen peroxide and malondialdehyde, increasing the chlorophyll content, and increasing the production of compatible osmolytes compared to the treatment without these two hormones.
کلیدواژهها [English]
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