Forestry Sciences Laboratory, U.S.D.A. Forest Service, Pacific Northwest Forest and Range Experiment Station, Olympia, Washington.
J Chem Ecol. 1982 Jan;8(1):241-53. doi: 10.1007/BF00984020.
Yield and composition of essential oils were compared in foliage, stems, and roots of ponderosa pine seedlings, and preferences for the trees by pocket gophers were determined. Test seedlings represented nine widely separated provenances in the western United States. Seed source of the trees influenced gopher feeding preferences and resulted in varied tree damage. The damage ranged from 0 to 31%, suggesting that some sources might possess sufficient natural resistance to give trees practical protection from gophers in the field. There were no morphological differences among sources to explain differential tree damage. All sources contained essential oils in all tissues examined, but oil yield varied among and within tissue types. Oils were predominantly (76-97%) composed of monoterpene hydrocarbons. Oil composition varied by source, and different tissue types varied greatly in the yield and composition of their oils. Neither yield nor constituents of foliage oils were significantly correlated with gopher damage (or preference). In contrast, some components of stem and root oils were strongly related to preference. Results of correlation and discriminant analyses showed that some oil constituents could serve as indicators of resistance (or susceptibility) to gopher damage. Such important chemical variables, when verified, could be used in selections for ponderosa pine resistant to gophers.
油的产量和成分在辐射松幼苗的叶、茎和根中进行了比较，并确定了囊鼠对树木的偏好。测试的幼苗代表了美国西部九个相距甚远的种源。树木的种子来源影响了囊鼠的摄食偏好，导致了不同程度的树木损害。损害程度从 0 到 31%不等，这表明一些来源可能具有足够的天然抗性，使树木在野外实际免受囊鼠的侵害。来源之间没有形态差异来解释树木损害的差异。所有来源在所有检查的组织中都含有精油，但油的产量在组织类型之间和内部有所不同。油主要由单萜烃组成（76-97%）。油的组成因来源而异，不同的组织类型在油的产量和成分上差异很大。树叶油的产量和成分与囊鼠的损害（或偏好）均无显著相关性。相比之下，茎和根油的一些成分与偏好有很强的相关性。相关和判别分析的结果表明，一些油成分可以作为对囊鼠损害的抗性（或易感性）的指标。这些重要的化学变量，如果得到验证，可以用于选择对囊鼠有抗性的辐射松。
