Effect of Different Concentrations of Chromium (ш) on Morphological Characteristics and Essential Oil Chemical Composition of Basil

Increasing concentration of heavy metals causes considerable harmful effects on soil. Due to enhanced application of fertilizers, pesticides and also increasing urbanization and industrial activities, accumulation of heavy metals in medicinal plants may be occurred. In this research, effects of chromium toxicity on some morphological characteristics and essential oil chemical composition of basil (Ocimum basilicum L.) under controlled conditions were studied. Therefore, effects of six treatments of Cr (control, 0.01, 0.1, 1, 5, 10 mM) based on a completely randomized design with 4 replications in perlite culture was studied. The results of data analysis of variance showed that the effects of different concentrations of Cr on morphological characteristics of shoot and root and essential oil chemical composition were significant. The application of different Cr concentrations decreased morphological characteristics, this reduction was a significant amount compared to the control treatment. It was observed that substrate pollution with heavy metals like Cr inhibited the absorption of essential elements to the plants shoot and thus, repelled the growing process. Different concentrations of chromium increased main compounds of Basil essential oil, such as Linalool and Eugenol and this rise was the result of the stress of chrome and induction of defense responses and stimulation of the bio synthesis's path and the accumulation of essential oil.