红脂大小蠹诱导油松树干挥发性单萜相对含量的变化

使用Porapak Q吸附剂,采用动态顶空的吸附方法,连续抽取11个不同阶段的对照、损伤与虫害油松的挥发物成分.运用GC、GC-MS与图谱峰面积进行挥发物成分定性与单萜相对含量的定量分析.与对照和损伤油松相比,虫害油松含有高比率的(+)-α-蒎烯(超过90％)和月桂烯,但(+)-3-蒈烯,(-)-β-蒎烯,莰烯和柠檬烯含量较低.(+) -3-蒈烯含量对照和损伤油松高于虫害油松(低于4％).(+)-3-蒈烯含量从损伤4天后的最低水平逐渐恢复到对照油松中含量水平.(-)-β-蒎烯和柠檬烯在不同处理的油松中含量相近,但在接入雌雄虫后3个处理间存在显著差异.尽管目前不确定我国的红脂大小蠢是否在危害油松后释放信息素,但研究表明红脂大小蠢可能会利用各种单萜成分细节上的变化作为化学信号,从而实现寄主的选择和种群聚集.本研究对于揭示油松抗性机制,完善红脂大小蠢的监测与防控技术体系具有重要意义.

Variance in Relative Concentration of Induced Volatile Monoterpenes Composition of Pinus tabulaeformis by Dendroctonus valens

The volatiles of the male Dendroctonus valens infected, artificially damaged and control Chinese pine (Pinus tabulaeformis), were extracted with Porapak Q absorbent in headspace absorption method for eleven consecutive stages. The chemical constituents of the volatiles were analyzed by GC and GC-MS and their relative contents of monoterpenes were determined by the normalized peak areas. The infected pines contained significantly higher ratios of (+)-α-pinene (more than 90%) and myrcene, but lower levels of (+)-3-carene, (-)-β-pinene, camphene and limonene, when compared to the control and damaged trees. The abundance of (+)-3-carene (less than 4%) in the infected pines was lower than that in control and damaged pines. However, the abundance of (+)-3-carene in damaged pines reached to the level of control pines gradually from a lower level. The abundance of (-)-β-pinene and limonene was similar in different treatment pines, but there were significant differences among them after infected by male accompanied with femal D. valens. Although it is unknown whether D. valens releases pheromone after attacking Chinese pine in China, our results suggest that D. valens might use specific variations of composition of the monoterpenes as chemical cues for host tree selection and population aggregation. Meanwhile, this study has an important significance for explaining resistance mechanism of Chinese pine and improving the monitor and control system for D.valens.