CHANGES IN ESSENTIAL IN OIL CONTENT AND COMPOSITION WITH LEAF DEVELOPMENT IN OCIMUM GRATISSIMUM L.

Ocimum gratissimum L., native to Africa, is a shrubby essential oil containing plant with medicinal, antimicrobial and anthelminthic properties. The present work was conducted to study the relationship between leaf development and essential oil content and composition in a unique geraniol-rich chemotype of O. gratissimum.

A mature plant of O. gratissimum was harvested at full flowering. The main branch with side stem was cut off, the leaf pair at each internode removed and analyzed for total essential content and composition. The total essential oil content and total geraniol content increased with leaf development and expansion until leaves were fully mature, and then decreased. The relative percentage of geraniol in the oil increased from 51.6% in the very young leaves to 73.3% in the mature leaves and then decreased to 64.2% in senescing leaves. The total sesquiterpene percentage decreased from 42.9% in the very young leaves to 20.2% in mature leaves and 26.9% in senescing leaves. Of the 17 essential oil constituents identified in the oil, most were present in all leaf development stages. This chemotype of O. gratissimum may have potential as an alternative source of geraniol for the perfume and flavor industry.