Monoterpene composition and fusiform rust resistance in slash and loblolly pines

Monoterpene composition of cortical tissue was analyzed in slash pine (Pinuselliottii Engelm. var. elliottii) and loblolly pine (Pinustaeda L.) clones with known breeding values for fusiform rust resistance. Trees having a relatively high content of ?-phellandrene tend to be more resistant than trees with a low ?-phellandrene content. Such results confirm previous data and suggest the utilization of ?-phellandrene content as an aid in selecting relatively rust resistant slash and loblolly pines.