Preferred Age for Assessment of Qualitative and Quantitative Characteristics of the Essential Oil of Tea Tree (Melaleuca alternifolia) Seedlings Prior to Plantation Establishment

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• 作者：Michael F. Russell and Ian Southwell
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2003
• 出版时间：July 16, 2003
• 年：2003
• 卷：51
• 期：15
• 页码：4254 - 4257
• 全文大小：90K
• 年卷期：v.51,no.15(July 16, 2003)
• ISSN：1520-5118

文摘

An analytical method for determining the quality and hence the chemical variety status of tea treetransplants is described. The key to the procedure was found to be the leaf age of the test material.Investigation at very early development stages was seen to give misleading results due to thesequential onset of different monoterpenoid biogenetic pathways. For example, in the first few leaves,the high concentration of terpinolene in the terpinen-4-ol variety suggests that the terpinolene varietyis under investigation. However, 1,8-cineole percent concentrations in plantation tree leaf were ~1.6times lower than those measured for seedlings prior to transplant. Consequently, the use of a plantationcineole indicator is proposed for estimating plantation cineole from seedling leaf analyses. Althoughrecent investigations enable the chemotype status to be predicted with some certainty, it is nowproposed that analysis of leaf set 10 at the age of 6 weeks (seedling age ~17 weeks) provides anunambiguous analysis and correlates seedling quality with mature plantation quality. In addition, theoil yield of mature tea tree leaf was found, by steam distillation, to be ~5 times higher than that ofseedling leaf.Keywords: Tea tree; Melaleuca alternifolia; chemotypes; 1,8-cineole type; terpinolene type; terpinen-4-ol type; transplant quality; leaf microanalysis; gas chromatography