Department of Biological Sciences, University of Alberta, CW405 Biological Science Building, Edmonton, Alberta, T6G 2E9, Canada.
J Chem Ecol. 2011 Sep;37(9):1013-26. doi: 10.1007/s10886-011-0008-3. Epub 2011 Aug 27.
The mountain pine beetle (Dendroctonus ponderosae, MPB) has killed millions of lodgepole pine (Pinus contorta) trees in Western Canada, and recent range expansion has resulted in attack of jack pine (Pinus banksiana) in Alberta. Establishment of MPB in the Boreal forest will require use of jack pine under a suite of environmental conditions different from those it typically encounters in its native range. Lodgepole and jack pine seedlings were grown under controlled environment conditions and subjected to either water deficit or well watered conditions and inoculated with Grosmannia clavigera, a MPB fungal associate. Soil water content, photosynthesis, stomatal conductance, and emission of volatile organic compounds (VOCs) were monitored over the duration of the six-week study. Monoterpene content of bark and needle tissue was measured at the end of the experiment. β-Phellandrene, the major monoterpene in lodgepole pine, was almost completely lacking in the volatile emission profile of jack pine. The major compound in jack pine was α-pinene. The emission of both compounds was positively correlated with stomatal conductance. 3-Carene was emitted at a high concentration from jack pine seedlings, which is in contrast to monoterpene profiles of jack pine from more southern and eastern parts of its range. Fungal inoculation caused a significant increase in total monoterpene emission in water deficit lodgepole pine seedlings right after its application. By 4 weeks into the experiment, water deficit seedlings of both species released significantly lower levels of total monoterpenes than well watered seedlings. Needle tissue contained lower total monoterpene content than bark. Generally, monoterpene tissue content increased over time independent from any treatment. The results suggest that monoterpenes that play a role in pine-MPB interactions differ between lodgepole and jack pine, and also that they are affected by water availability.
山松甲虫（Dendroctonus ponderosae，MPB）已经在加拿大西部杀死了数百万株黑云杉（Pinus contorta），并且最近的范围扩大导致了在艾伯塔省对短叶松（Pinus banksiana）的攻击。在北方森林中建立 MPB 将需要在一系列不同于其在原生范围内通常遇到的环境条件下使用短叶松。云杉和短叶松幼苗在受控环境条件下生长，并接受水分亏缺或充分浇水条件以及 Grosmannia clavigera（MPB 的真菌伴生菌）的接种。在为期六周的研究过程中，监测了土壤水分含量、光合作用、气孔导度和挥发性有机化合物（VOC）的排放。实验结束时测量了树皮和针叶组织中的单萜含量。β-蒎烯是黑云杉中主要的单萜，在短叶松的挥发性排放物中几乎完全缺失。短叶松的主要化合物是α-蒎烯。这两种化合物的排放都与气孔导度呈正相关。3-蒈烯是从短叶松幼苗中以高浓度排放的，这与它在其分布范围的更南部和东部地区的短叶松的单萜谱形成对比。真菌接种在应用后立即导致水分亏缺的云杉幼苗中单萜总排放量显著增加。到实验进行到 4 周时，两种物种的水分亏缺幼苗释放的总单萜量明显低于充分浇水的幼苗。针叶组织中单萜总含量低于树皮。一般来说，单萜组织含量随着时间的推移而增加，与任何处理无关。结果表明，在云杉-MPB 相互作用中起作用的单萜在黑云杉和短叶松之间存在差异，并且它们也受到水分供应的影响。
