Differential patterns of mono- and sesquiterpenes with leaf ontogeny influence pharmaceutical oil yield in Eucalyptus polybractea R.T. Baker

Abstract

Pharmaceutical 1,8-cineole oil is commercially harvested from Eucalyptus polybractea R.T. Baker grown in short rotation coppice cultivation. Harvests occur throughout the year, with no consideration given to the proportion of leaves present at different ontogenetic stages, and the effect leaf ontogeny may have on harvested oil quality and quantity. To determine the optimal leaf stage to harvest pharmaceutical-grade oil, we quantified the relationship between leaf ontogeny and foliar oil quantity and quality, secretory cavity size, and abundance along branches of two E. polybractea clones. The results show that the desirable attributes of oil yield and 1,8-cineole proportion both reach their ..