The Effect of Foliar Application of Seaweed Extract on Morphological and Physiological Traits of Echium amoenum Fisch. & Mey Seedlings under Salinity Stress

Introduction Historically, medicinal plants have been one of the most important resources for therapeutic purposes, and even today, their use is expanding in many developed countries. Salinity stress is a major factor that limits plant growth by reducing metabolic and physiological activities. One of the effects of salinity stress is the increased production of abscisic acid in plants. In recent years, the use of seaweed and its extracts has been tested as a method to mitigate the effects of salinity stress on plants. According to the studies conducted in some plants, seaweed extract can cause the growth and expansion of the roots and help to increase the absorption of water and minerals through the roots. Also, based on the research conducted on some plants, the use of seaweed increases the amount of chlorophyll in the plant and accelerates the time of flowering and fruit formation in the plant. Echium amoenum is a perennial plant belonging to the family Borage is a valuable plant in terms of its medicinal properties is considered. In general environmental factors have a significant effect on flower production in these plants. Therefore, for the successful cultivation of medicinal plants, including in general environmental factors have a significant effect on flower production in these plants. Therefore, for the successful cultivation of medicinal plants, including Echium amoenum, providing optimal environmental conditions is a priority, providing optimal environmental conditions is a priority. Ascophyllum nodosum seaweed extract contains significant amounts of high-use mineral elements such as nitrogen, potassium, calcium, magnesium, and low-use mineral elements such as iron, copper, and manganese. Therefore, according to the current results, in this study, the effect of foliar spraying of algae extract was investigated. The morphological characteristics of Echium amoenum seedling under salt stress were investigated Materials and Methods In order to investigate the effects of foliar spraying of seaweed extract on borage flower seedlings under salinity stress conditions, a factorial experiment was conducted with two factors of seaweed and salinity stress with sodium chloride salt, in the form of a completely randomized design in the greenhouse. The seeds were purchased from Pakan Seed Company of Isfahan and soaked in normal water for 24 hours, and then they were transferred into small pots containing three parts of peat moss and one part of perlite. One week after transferring the seedlings to the main pots, foliar spraying with seaweed extract was done. Foliar-spraying was repeated once every two weeks and in total the seedlings were sprayed three times with seaweed extract. In this experiment, a concentration of 1500 ppm of seaweed extract and three levels of salinity (EC=1.6, 4, 8) were used. The seaweed extract used in this experiment belonged to Akadin Company. The type of seaweed from which the extract was prepared was Ascophyllum nodosum and it is a type of brown algae. One week after the first foliar application of seaweed extracts, the application of salinity stress began. In order to prevent shock in plants, salinity treatment was done gradually and in three stages. In order to prevent salt accumulation, washing with ordinary water was done once every two weeks. Results and Discussion The results showed that the use of seaweed extract can significantly protect plant growth under salinity stress. Seaweed extract increased the amount of proline and potassium in the leaves of the plant and thereby reduced the harmful effects of salinity stress on the borage plant. In addition, foliar spraying of borage plant with the use of seaweed extract increased the amount of chlorophyll in the plant, and in this way, by increasing the amount of photosynthesis in the plant; it helped the plant to grow better under salt stress conditions. The results of this research indicate that the use of seaweed extract helps plants maintain their health under salt stress by increasing proline levels and enhancing potassium absorption in plant tissues. Additionally, foliar spraying with seaweed extract preserves the chlorophyll structure in plants experiencing salinity stress, thereby increasing photosynthetic efficiency and promoting better growth under such conditions. Conclusions Based on the results obtained, it can be concluded that seaweed can mitigate the negative effects of salinity stress in Iranian borage seedlings. Furthermore, due to its low cost and availability, it can serve as a suitable bio-fertilizer to support plant growth in saline conditions.