Evaluation of antioxidant enzymes activity, proline content and Basil (Ocimum basilicum L.) essential oil yield under leaf foliar application of salicylic acid in drought stress conditions
Subject Areas : Crop Production ResearchZabiholah Rostami 1 , Saeed Sayfzadeh 2 , ناصر شهسواری 3
1 - Department of Agronomy, Takestan Branch, Islamic Azad University, Takestan, Iran.
2 - Department of Agronomy, Takestan Branch, Islamic Azad University, Takestan, Iran.
3 - گروه تولیدات گیاهی، دانشگاه آزاد اسلامی واحد حاجی اباد
Keywords: Anti-oxidant enzymes, Basil, Drought stress, Essential oil, Proline, Salicylic acid,
Abstract :
Basil (Ocimum basilicum L.) is one of the plants of the mint family, it has many uses as fresh food and medicinal uses. Water is one of the most important factors in the production of plants, and its limitation in Iran, especially in recent years, is the main factor that reduces the yield of plants. In order to investigate the evaluation of antioxidant enzymes activity, proline content and Basil (Ocimum basilicum L.) essential oil yield under leaf foliar application of salicylic acid in drought stress conditions, an experiment was conducted in the form of split plots based on randomized complete block design in 3 replications in a private farm located in Mahdasht area of Karaj city in 2015-2016 and 2016-2017 crop years. Irrigation regimes in 4 levels: I1: 100%, I2: 80%, I3: 60% and: I4: 40%. The volume of water required in the main plots and salicylic acid in 5 levels: SA1: No application (spraying solution with water net as control), SA2: foliar spraying with a concentration of 50 μM, SA3: 100 μM, SA4: μM and SA5: 200 μM were placed in the subplots. The results showed that the amount of amino acid proline and the activity of antioxidant enzymes catalase, superoxide dismutar and ascorbate peroxidase increased with increasing drought stress. Also, salicylic acid foliar application, by increasing proline as an osmolyte and increasing the activity of antioxidant enzymes, moderated the drought stress and maintained yield to a large extent. The highest yield of essential oil from the treatment of 100% water requirement with the use of 200 µM salicylic acid is 11.982 kg/ha) and in humidity conditions of 40%, 60% and 80% of the water requirement of the plant with the use of 200 µM salicylic acid, respectively, at the rate of 11.730, 11.287 and 10.329 kg/ha were obtained. A significant increase in the performance of essential oil was observed in this study by increasing the consumption of salicylic acid from zero to 200 μM. Finally, due to the adverse effect of drought stress on the growth and production of basil plant, it is recommended to use a concentration of 200 μM salicylic acid to moderate drought stress and improve yield.
