Effects of mechanical wounding on concentration and composition of essential oil from Melaleuca alternifolia leaves

The effects of mechanical damage on the essential oil obtained from Melaleuca alternifolia leaves were determined by post-wounding field experiments at 24 and 48 h. The rupture of oil glands caused by mechanical damage resulted in a decrease in oil concentration in mature and immature leaves in the first 24 h, but mature leaves were found to recover most of their loss 48 h after damage. Post-wounding changes in the oil composition from mature and immature leaves were also detected. The response of the mature leaves was expressed by different oil constituents for every post-wounding day elapsed. Results also indicated that wounding of immature leaves affects their chemical maturation. The post-wounding response in both leaf types was found to be independent from the pre-wounding levels of the particular compounds expressing the response and the overall leaf oil-composition.