RELATIVE AMOUNTS AND ENANTIOMERIC COMPOSITIONS OF MONOTERPENE HYDROCARBONS IN XYLEM AND NEEDLES OF PICEA-ABIES

The relative amounts of 23 monoterpene hydrocarbons, including enantio mers, present in extracts of branch xylem and needles from 41 Picea ab ies plus-trees of widely different origins, were determined. A two-dim ensional gas chromatographic system was used for the determination of the enantiomeric compositions of the seven major chiral monoterpenes. Data were evaluated by multivariate data analysis. Large variations we re found in the enantiomeric compositions, as well as in the relative amounts of the monoterpenes, both within and among the trees. Trees fr om the same geographic area did not show a greater similarity in their composition of volatiles than trees from different geographic areas. In the xylem, (-)-beta-pinene and (-)-beta-phellandrene, and in the ne edle samples, (-)-alpha-pinene, (-)-limonene and (-)-camphene, dominat ed over their (+)-enantiomers. Among-tree variation in enantiomeric co mposition was higher in xylem samples than in needle samples, except f or beta-pinene and beta-phellandrene.