Genetic Variation in the Monoterpene Composition of White Spruce

Abstract

Abstract Monoterpene composition of cortical oleoresin samples was determined for 16 populations of white spruce growing in a replicated plantation in southern Michigan. Four of the 9 measured monoterpenes differed significantly among origins. β-pinene, 3-carene, and β-phellandrene were lower in western than in eastern sources, whereas limonene was highest in the western sources. A cluster analysis of the data, together with growth information, suggests that white spruce consists of two clines extending from the Lake States-Ontario northwestward to Alaska, and northeastward into Labrador. Individual monoterpenes appear to be controlled by few but varying numbers of genes. Significant correlations occurred between individual monoterpenes, but only the positive correlation between 3-carene and terpinolene is considered meaningful in relation to monoterpene biosynthesis. Forest Sci. 17:83-90.