Impact of geographical locations on essential oil composition and leaf histochemistry in Cinnamomum verum J. S. Presl

Abstract

Cinnamomum verum is worldwide well-known for its culinary and medicinal properties. The distinguished aroma of this plant is due to the presence of oil cells containing oil drops which are known as the primary site of essential oil biosynthesis. In this study, we compared the content and composition of essential oils of C. verum leaves of two distinct seasons from two different geographical regions, viz. Kharagpur (Cv-K) and Mamit (Cv-M) - the eastern and north-eastern regions of India, respectively. The leaf essential oils of the Kharagpur region were mainly composed of phenylpropanoids (81.98%) while monoterpenoids (48.42%) dominated in the Mamit region. The major components of Kharagpur and Mamit chemotypes were eugenol (81.83±2.09%) and linalool (37.52±7.06%), respectively. Transverse sections obtained through cryomicrotomy showed the presence of lipids and terpenes in the oil droplets upon staining with Sudan III and Nadi, respectively. Though, histochemical analyses did not show any distinct differences in the secretory structures of C. verum growing in two different geographical locations, absence of crystal in Cv-M type leaves was noted. Because of substantial differences in the chemical composition of essential oils, these two populations of C. verum can be considered as two distinct chemotypes.