油松萜烯成分变化与红脂大小蠹的反应特性

采用顶空采样方法,比较健康油松、人工损伤油松以及抗性油松在单萜烯成分组成上的差异。GC-MS分析表明,在自然状况下,油松树干释放的萜烯类成分很少,以α-蒎烯占绝对优势(>97%);人工损伤后,油松萜烯类成分明显增多,除α-蒎烯为主要成分外,还包括β-蒎烯、月桂烯、柠檬烯、萜品油烯、β-水芹烯、长叶烯等;而抗性油松萜烯类成分更为复杂。对3类油松主要单萜类成分的相对含量方差分析表明,α-蒎烯的相对含量呈显著降低;3-蒈烯在损伤寄主中相对含量最高,在抗性寄主中相对含量与自然状态下没有差异。柠檬烯、莰烯、萜品油烯在抗性寄主中相对比率显著增加。而β-蒎烯、月桂烯、β-水芹烯相对含量在3个处理中变化不大。在此基础上,比较红脂大小蠹Dendroctonus valens LeConte对油松主要单萜类成分的触角电位及嗅觉行为反应。结果表明,室内触角电位、嗅觉试验与先前林间试验结果相一致,即红脂大小蠹对(+)-3-蒈烯表现出最强的电生理和行为反应。对R-(+)-α-蒎烯和S-(-)-α-蒎烯研究发现,红脂大小蠹对α-蒎烯2个对映体的触角电位、嗅觉行为无显著不同。结合油松单萜类含量变化特点与红脂大小蠹行为反应,认为3-蒈烯相对含量上升可能作为易感寄主特点;而柠檬烯、莰烯、萜品油烯相对比率增加则代表了抗性或者非适合寄主的特征。

The variance in monoterpene composition of Pinus tabuliformis and their effect on the electrophsiological and behavioral responses of Dendroctonus valens

The volatiles profiles of health, damaged and resistant Chinese pine, Pinus tabuliformis, were surveyed with Super-Q absorbent in headspace absorption method. GC-MS analysis showed that few monoterpenes were detected from health pines, in which α-pinene accounted for more than 97%. After pines were damaged, several kinds of monoterpene were released, includig α-pinene, camphene, 3-carene, β-pinene, myrcene, limonene, terpinolene, β-phellandrene and longifolene. The composition of monoterpenes in resistant pines was more complex than damaged pines. ANOVA analysis showed that the relative abundance of α-pinene displaying an obvious decreasing in the sequence of health pines > damaged pines > resistant pines. The abundance of 3-carene in damaged pines was higher than that in healthy and resistant pines. The relative content of limonene, camphene and terpinolene in damaged pines increased significantly. The abundance of β-pinene, myrcene and β-phellandrene were similar in different pines. Electroantennagram (EAG) and olfactometer were employed to analyze the antennal and behavioral responses of Dendroctuns valens LeConte to the major monoterpenes in laboratory. It was consistent with the previous field results that (+)-3-carene was the most antennal active and attractive to D. valens. There was no significant difference between (R)-(+)-α-pinene and (S)-(-)-α-pinene in antennal and olfactory responses by D. valens. The importance of monoterpenes quantitative differences in host location of D. valens was discussed.