Abstract Cortical oleoresin samples were obtained from two 19-year-old loblolly pine provenance tests in Tennessee. Gas chromatography was used to determine qualitative identification of individual monoterpenes. Considerable variation was found in cortical monoterpene composition; beta-pinene, myrcene, limonene, and beta-phellandrene showed bimodality, while the alpha-pinene data had normal distribution. Twelve of sixteen possible phenotypes occurred when each tree was classified as being "high" or "low" for each of the four monoterpenes showing bimodality. High amounts of limonene and beta-phellandrene occurred in greater percentages in trees of western origins, while high amounts of myrcene were frequently found in eastern trees. Distribution of beta-pinene was patchy and no trend was identified. A trend of increasing percent alpha-pinene content in a southwest to northeast pattern was indicated. It appears that cortical monoterpene composition pattern can be useful for identifying the origin of trees planted in commercial plantations. Identification of provenance may be of great value when phenotype selections are made in commercial plantation. Forest Sci. 28:732-736.
McRae et al. (Wed,) studied this question.