【作者】 霍燕；

【导师】 陈辉；

【作者基本信息】 西北农林科技大学 ， 野生动植物保护与利用， 2010， 硕士

【摘要】 华山松(Pinus armandi Fr.)是我国秦岭最重要的针叶树种和我国长江中上游主要造林树种,但自上世纪50年代以来,秦岭林区华山松持续遭受华山松大小蠹(Dendroctonus armandi Tsai et Li)的危害,导致该区域内30年以上健康华山松大量死亡,直接威胁秦岭森林生态系统的稳定性和可持续发展。小蠹类森林害虫对寄主树木具有高度选择性,可利用寄主树木萜烯类挥发性物质合成聚集信息素等使其能够高密度入侵寄主树木。为此,小蠹虫对寄主树木挥发性物质的选择机制、寄主树木挥发性物质的组成、寄主树木挥发性物质的扩散等成为揭示小蠹虫空间动态、种群扩散研究的重点和热点。目前,秦岭华山松挥发性物质扩散的动态尚未研究报道。本研究旨在通过对秦岭华山松挥发性物质扩散规律、时序动态研究,揭示华山松大小蠹在秦岭森林生态系统的分布、华山松大小蠹对寄主树木的时空选择机制。本文应用动态顶空吸附法结合气相色谱-质谱联用(GC-MS)技术,对健康华山松和受害华山松针叶、树干韧皮部挥发性物质进行分析,得出以下研究结果:1.结果鉴定出华山松健康木和受害木(依次包括新侵木、枯萎木、枯立木)针叶、树干韧皮部具有α-蒎烯、莰烯、β-蒎烯、β-香叶烯、D-苧烯和β-水芹烯6种单萜类挥发性物质。2.华山松健康木与受害木针叶单萜化合物变化:α-蒎烯、β-蒎烯、β-水芹烯相对含量在健康木和新侵木中差异不显著,但随着危害的加深在枯萎木中,α-蒎烯增高,而β-蒎烯、β-水芹烯有所降低。莰烯和D-苧烯均表现为在新侵木中相对含量最高。β-水芹烯在枯萎木针叶中未检测到。3.华山松健康木与受害木树干韧皮部单萜化合物变化:随着危害的加深,除D-苧烯相对含量逐渐增高,其余均在健康木和新侵木中差异不显著。而α-蒎烯、莰烯以及β-香叶烯在枯萎木和枯立木中含量差异不显著,但α-蒎烯、莰烯较前两阶段有所增加而β-香叶烯则有所降低;β-蒎烯和β-水芹在枯萎阶段和枯立阶段相对含量相继下降,且均低于前两个阶段。4.华山松单萜化合物相对含量在针叶和树干韧皮部之间存在明显差异,无论是健康木、新侵木还是枯萎木。本研究表明,α-蒎烯、β-蒎烯以及β-香叶烯可能是影响华山松大小蠹对寄主植物不同部位选择的重要信号物质。5.α-蒎烯、β-蒎烯和β-水芹烯相对含量在健康木和新侵木中无明显差异,但随着华山松大小蠹危害的加剧,在枯萎木和枯立木中α-蒎烯含量显著增高,而β-蒎烯和β-水芹烯则明显降低。这可能与华山松大小蠹入侵危害导致健康华山松树势衰弱和诱发被害华山松次生抗性(树脂代谢)有关,也可能是华山松被害和树势衰弱的重要信号。更多还原

【Abstract】 Chineses white pines (Pinus armandi Fr.) are the most important conifer species in Qinling Mountains, Northwest China, and main forestation species in upper and middle reaches of Yangtze River, China. But since the 50s of last century, P. armandi of Qinling Forest were damaged continuously by Dendroctonus armandi Tsai et Li, which led to a large number of deaths of healthy P. armandi at age over 30 years, and directly threatened the stability and sustainable development of Qinling forest ecosystem. Bark beetles have a high degree of selectivity on host trees. And they can use terpene volatiles from host trees to synthesize aggregation pheromones, etc, which enables the beetles to inbreak host trees with high density. So the selection mechanism of D. armandi, the composition and diffusion of host tree volatiles, etc, have became the keystone and focus to reveal the spatial dynamics and population diffusion of bark beetles. At present, diffusion dynamics of volatiles of P. armandi in Qinling Mountains have not been reported. This study was desigened to study the diffusion rules and temporal dynamic of volatiles from P. armandi in Qinling Mountains, which can reveal the distributing rules, temporal and spatial selection mechanism of D. armandi on host trees in Qinling forest ecosystem.In the study, the volatiles from needles and trunk phloem of healthy and attacked P. armandi were analysed through dynamic headspace adsorption method and gas chromatography-mass spectrometry (GC / MS) technology. And the results were as follows:1.The results identified that the volatiles from needles and trunk phloem of healthy and attacked P. armandi (including newly attacked wood, withered wood and dead wood in sequence) were six monoterpenes:α-pinene, camphene,β-pinene,β-myrcene, D-Limonene andβ-phellandrene.2. The monoterpenes change from needles of healthy and attacked P. armandi: the differences of relative content ofα-pinene,β-pinene,β-phellandrene were not significant in healthy and newly attacked trees; but along with the deepening of damage,α-pinene increased, whileβ-pinene andβ-phellandrene decreased in withered trees. Both of Camphene and D-limonene showed the highest relative content in newly attacked trees.β-phellandrene were not detected from needles in withered tree.3. The monoterpenes change from trunk phloem of healthy and attacked P. armandi: with the deepening of damage, the relative content of D-limonene increased gradually, while the content of the rest monoterpenes had no significant change in healthy and newly attacked trees. In withered and dead trees, the differences of the relative content ofα-pinene, camphene andβ-myrcene were not significant; butα-pinene, camphene increased over the previous two stages, whileβ-myrcene decreased; the relative content ofβ-pinene andβ-phellandrene were lower than the previous two stages and decreased in sequence.4. The relative content of monoterpenes between needles and trunk phloem of P. armandi had significant differences, whether in healthy trees, newly attacked trees or withered trees. This study showed thatα-pinene,β-pinene andβ-myrcene might be important signal substances that affected D. armandi to select different positions on host trees.5. the relative content ofα-pinene,β-pinene andβ-phellandrene had no significant differences in healthy and newly attacked trees. However with the deepending of damage from D. armand, in withered and dead trees, the content ofα-pinene was significantly higher, while the content ofβ-pinene andβ-phellandrene were significantly lower than the previous two stages. This rule might be related to weakness of healthy P. armandi affected by D. armandi and inducing secondary resistance of attacked P. armandi(Resin metabolism), also might be important signals of being attacked and weakness of D. armandi.更多还原