Seed Priming Mellissa officinalis L. with Potassium Nitrate and Inoculation with Plant Growth Promoting Rhizobacteria at Different Times

Priming seed priming and seedling inoculation with bio elicitor improve growth and phytochemical constituents of medicinal plants. This study was conducted with the aim of investigate the role of seed priming with potassium nitrate (۰, ۰.۲۵, ۰.۵, ۰.۷۵ and ۱%) at different times and inoculation of seedling originated from primed seeds with rhizobacteria strains (Pseudomonas fluorescens and P. putida) on physiological and metabolic attributes of Melissa officinalis L. The results showed that the interaction of treatments on morphological, physiological, photosynthetic pigments, metabolic traits contain percentage and essential oil composition were significant at ۰.۲۵% concentration of potassium nitrate with ۷۲ hours priming of P. putida bacteria inoculation. The phenolic contents increased (۵۶.۳۰ mg. g-۱ of gallic acid per ml of extract) in inoculation of P. putida and P. fluorescens bacteria while the highest antioxidant activity (۵۰.۰۵ mg. ml-۱) was noticed in inoculum of P. fluorescens bacteria with ۱۲ hours of priming. In addition, remarkable increase of ۲۰% was observed in essential oils and related compounds such as carvacrol, thymol and isomenthone. Overall, seed priming along with seedling inoculation with pseudomonas strains play vital role in the increase in both primary and secondary metabolites of lemon balm plants.

کلیدواژه ها:

biotic elicitor ، Mellissa officinalis ، photosynthetic pigments ، Potassium nitrate