Effect of carbon sources of ethanol and methanol on morpho-physiological parameters of Melissa officianlis L.

In order to investigate the effect of different carbon sources (ethanol and methanol) on some morphological and physiological characteristics of Melissa officianlis L., a pot experiment was conducted in factorial based on completely randomized design with three replications in the research greenhouse of Shahed University in 2018. Foliar treatments included different concentrations of 0, 15, 30 and 45% ethanol and methanol. The results showed that ethanol 15% had the most effect on leaf number per plant and total flavonoid. As ethanol concentration increased by 15%, the flavonoid content decreased, so that at 45% ethanol concentration, its inhibitory effects appeared. The highest plant height and protein percentage were obtained in 15% methanol and 45% ethanol treatments, respectively. The highest percentage and yield of essential oil were obtained from methanol treatment with 45%. The combined application of 15% ethanol and 45% methanol, produced the highest biological yield, chlorophyll a, chlorophyll b and total chlorophyll. Therefore, the use of alcoholic compounds such as methanol and ethanol is one of the appropriate strategies to improve the yield and quality of Melissa officianlis L.