Using essential oil composition to discriminate between myrtle rust phenotypes in Eucalyptus globulus and Eucalyptus obliqua

•Stepwise selection identified terpenes in association with rust response phenotypes.•Use of discriminant analysis to study association between terpenes and rust susceptibility.•Eucalyptus terpenes significantly discriminating between distinct rust responses.•No transferring terpenes for significant rust resistance between Eucalyptus species.•Complexity of terpene defences against rust infection are worthy of further investigation.