Microsatellite analysis of tea tree (Myrtaceae) population genetics

Melaleuca alternifolia is grown for commercial production of Tea Tree oil which is used for pharmaceutical and cosmetic purposes. Considerable differences in oil yield and composition are of particular concern to commercial producers, and suggest significant genotypic variability. Microsatellite markers were developed using advanced enrichment techniques. Repeat sequences from digested tea tree DNA were hybridised to membrane-bound selected oligonucleotides. The plasmid-vector microsatellite library so enriched, is being used to analyse the genetic variation in tea tree within and between 630 individual samples from 42 populations throughout the entire range of the species, in north-eastern New South Wales, Australia. The aim of the project is to develop an understanding of the population genetics of M. alternifolia. This will indicate the most important plants to preserve for genetic variation in wild populations, and to harness in future varietal improvement programs. The level of outcrossing and the variation in oil yield and quality characteristics will also be determined. Microsatellite markers will be related to oil quality characteristics of various genotypes. Furthermore, a genetic map will be generated from a population produced by crossing individuals of diverse oil phenotypes.