Abstract Diterpene resin acids of needle and cortex tissues from one Pinus strobus seed source, two P. nigra sources, and two P. sylvestris sources were identified and quantitatively determined by gas-liquid chromatography. Tissue samples of current year's shoots were collected from three trees of each source in June, August, and December. A combined total of 20 resin acids, including two unidentified acids in P. strobus needles, were found in the trees examined. Trends in resin acid composition in needles, associated primarily with shoot growth and maturation, were generally similar in all species, seed sources, and tissues, and often showed a pattern of increasing degree of oxidation during development. Changes in composition between the last two sampling times were smaller, suggesting that needle samples should be obtained in late fall or winter to obtain dependable resin acid data. The variety of resin acid components in cortex oleoresin was considerably more limited than in the needles and changes in composition during the year were not as pronounced. Forest Sci. 28:785-796.
Tobolski et al. (Wed,) studied this question.
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