INTRASPECIFIC VARIATION IN LEAF OILS OF MELALEUCA-ALTERNIFOLIA (MYRTACEAE)

Leaves from 109 trees in 11 populations spanning the geographic range of Melaleuca alternifolia were analyzed for qualitative and quantitati ve variation in essential oils. Significant differences in oil yield w ere recorded between populations indicating the potential for improvem ent from a breeding program. Considerable variation in oil composition was found, both among and within populations. Trees from the northwes tern populations produced a terpinolene-rich oil while eastern populat ions produced an oil with either terpinen-4-ol or 1,8-cineole as the m ajor component. Differences in terpene composition among populations s upport data from allozyme analyses suggesting genetic differentiation of populations in the northwestern extremity of the species range. The study confirms three previously identified chemical forms in eastern populations and proposes recognition of two chemical forms in northwes tern