Document Type : Research Paper - Medicinal Aromatic Plants

Authors

• Saeideh Alizadeh Salteh ¹
• Samaneh Khalaf Khani ²
• Parinaz Ferdowsi Qebchaq ²

¹ Associate Professor, Department of Horticultural Sciences, Faculty of Agriculture, University of Tabriz, Tabriz, Iran Tabriz, Iran.

² M.Sc. Graduate, Department of Horticultural Sciences, Faculty of Agriculture, University of Tabriz, Tabriz, Iran

Abstract

Introduction
Sodium nitroprusside (SNP) and triacontanol (Tria), as plant growth regulators, enhance plant growth and development and influence the production of secondary metabolites. Triacontanol specifically plays a key role in regulating various biochemical and physiological processes, including photosynthesis. This leads to increased growth, yield, and product quality, as well as improvement in active compounds in medicinal and aromatic plants under normal or stressful conditions. Triacontanol can exert this effect alone or in interaction with other hormones and plant growth regulators. Sodium nitroprusside is recognized as a plant growth regulator, acting as a mediator to perform its regulatory role. It is commonly used as a nitric oxide-releasing compound in plants, which, in solution, is light-sensitive, and its decomposition is accelerated by oxygen and high temperatures. Nitric oxide itself is considered a reactive nitrogen species that can act as a signaling molecule, mediating adaptive responses to biotic and abiotic stresses in plants. Furthermore, it functions as an antioxidant, scavenging free radicals and eliminating them. Dracocephalum moldavica L., commonly known as Moldavian balm, is an annual, aromatic herb from the mint family (Lamiaceae). Native to Central Asia and domesticated in Central and Eastern Europe, it holds significant economic and medicinal value. This study investigates the effects of SNP and Tria on the morphological changes, as well as, quantitative and qualitative performance of secondary metabolites, especially the essential oil yield of D. moldavica. 
Materials and Methods
This research was conducted as a factorial experiment using a completely randomized design with three replications at the Faculty of Agriculture, Tabriz University. The experimental factors included foliar application of three concentrations each of sodium nitroprusside (0, 0.5 and 1 mM) and tricanthanol (0, 0.5 and 1 mM) during the flowering stage. The evaluated traits included growth parameters (leaf area and number of lateral branches), shoot yield (fresh and dry weight), essential oil yield and percentage, biochemical characteristics (soluble solids, protein, flavonoid and total phenol content) and nutrient content (nitrogen, phosphorus, potassium and sodium) at the full bloom stage.
Results and Discussion
The results demonstrated significant effects of SNP and Tria interactions on leaf area and the number of lateral branches. SNP at 1 mM notably increased shoot fresh and dry weight. Different concentrations of Tria significantly influenced total soluble solids. Foliar applications of SNP and Tria significantly improved leaf tissue nutrient content, with the highest increases observed at 1 mM. Additionally, treatments with SNP and Tria, individually and in combination, significantly increased phenol, flavonoid and total soluble protein contents. The combination of 1mM SNP and 1mM Tria led to increases of 62.93 %, 51.24 %, and 34.92% in phenol, flavonoid, and protein content, respectively, compared to the control. The same treatment also increased the essential oil yield by 207% compared to the control treatment.
Conclusion
The study underscore the significant impact of appropriate concentrations of sodium nitroprusside and triacantanol on the growth and yield of Moldavian Balm. Among all treatments, 1mM triacantanol combined with 1mM sodium nitroprusside was identified as the optimal treatment, offering substantial improvements in growth parameters, phytochemical content, and essential oil yield. 

Keywords

• Essential oil
• Growth regulator
• Medicinal plants
• Moldavian balm

Main Subjects

• H: Horticulture