Chemical Characterisation of Basil Germplasm for Essential Oil Composition and Chemotypes

Sweet basil (Ocimum basilicum L.) is a pleasant smelling perennial herb of high industrial importance for the essential oil and aroma chemicals. The plant possesses wide range of genetic variability as observed through plant morphology, phenology and oil composition. The present study was planned to evaluate thirty accessions of O. basilicum germplasm augmented from various geographical parts of India along with exotic collections from five countries. These accessions were grown at Issapur Experimental Farm, ICAR-NBPGR, New Delhi for characterisation for agro-morphological and chemical traits. The essential oil content estimated on fresh weight basis ranged from 0.13% to 0.32%. The maximum essential oil content was recorded in EC338772, EC387838 and IC110267. The composition of essential oils of basil germplasm was analysed by gas chromatography and gas chromatography-mass spectrometry. On the basis of chemical profiling, the O. basilicum germplasm exhibited four chemotypes: Linalool rich (EC312264, EC338772, EC174527, IC281185), methyl chavicol rich (EC338785, IC469904, IC370846), mixed chemotype having both methyl chavicol and linalool (EC388889, EC388737) and (E)-methyl cinnamate rich (IC261161). These chemotypic variations in chemical composition of basil oil will play an important role in evaluating their utilization and value for industrial application. Promising accessions identified may find use in perfumery and flavour industry based on major chemical compound present in them.