VARIATION IN LEAF WAXES OF THE TASMANIAN EUCALYPTUS SPECIES .1. SUBGENUS SYMPHYOMYRTUS

Leaf waxes were analysed from juvenile and adult leaves collected from natural populations of all Eucalyptus species from the informal subge nus Symphyomyrtus native to the island of Tasmania. Four species were from the series Ovatae (Eucalyptus barberi, E. brookeriana, E. ovata, E. rodwayi) and 13 were from the series Viminales (E. globulus ssp. gl obulus, E. vernicosa, E. subcrenulata, E. johnstonii, E. viminalis ssp . viminalis, E. dalrympleana ssp. dalrympleana, E. rubida, E. gunnii, E. archeri, E. morrisbyi, E, urnigera, E. perriniana and E. cordata). The major classes of compounds identified from hexane soluble leaf wax es were long chain hydrocarbons, aldehydes, alcohols, esters and beta- diketones: flavonoids and triterpenoids. Long chain P-diketones were t he major components of hexane soluble waxes of the majority of species , but some species had high proportions of long chain hydrocarbons, al dehydes or triterpenoids. Cluster analyses based on the percentage com position of leaf waxes resulted in the majority of populations of the Tasmanian Symphyomyrtus species clustering according to species with e xcellent differentiation of many species within series. The chemical c omposition of leaf waxes of juvenile and adult leaves was qualitativel y similar for most components and no significant quantitative differen ces were detected in most species. The relative ontogenetic stability of wax composition, coupled with the often clear differentiation of sp ecies, indicates the usefulness of biochemical markers derived from le af waxes for taxonomic and phylogenetic studies in the genus Eucalyptu s. (C) 1997 Elsevier Science Ltd.