Saline soil adaptations of Kratai Cham (Adenosma indianum (Lour.) Merr.): A comprehensive study on life cycle, leaf epidermis, and FTIR analysis of essential oils

Abstract

Kratai Cham (Adenosma indianum (Lour.) Merr.), similar to the camphor tree, produces fragrant essential oils rich in limonene found in glandular trichomes. These oils are renowned for their antibacterial, anti-inflammatory, and therapeutic properties in traditional medicine, particularly for neurodegenerative disorders. Recently, Kratai Cham has thrived in saline soils, prompting our investigation in Kalasin Province, Thailand, from 2019 to 2022. This research aimed to evaluate the influence of salinity on Kratai Cham, with particular relevance to its essential oils. The observation revealed that the life cycle of Kratai Cham spanned from July to February, and this cycle correlated with soil salinity, which ranged from 13.10 to 34.70 mmol Na/kg and 3.33 to 25.33 mmol Cl/kg. Salinity led to reduced stomatal size but increased numbers and indices of stomata and trichomes, notably the two glandular trichomes, capitate and peltate, on the lower epidermis. FTIR analysis revealed rising essential oil concentrations, particularly d-limonene, in response to salinity. Kratai Cham’s saline adaptations offer medical promise, underscoring the significance of this research for unlocking its potential.

Keywords

• stomata
• trichome
• saline
• epidermis
• limonene