Abstract:

The research focus on the optimum technological conditions of poplar bark volatiles CO₂ supercritical fluid extraction (SFE-CO₂) taking it rate as index by orthogonal experiment. The results showed that the extraction rate of the volatiles of Populus simonii, using SFE-CO₂, is 3.56% under the best condition of 25 Mpa pressure, 50 ℃ and the extracting time of 60 min. The volatiles of the barks of P.×xiaozhuanica cv. ‘Baicheng-2’, P.simonii，P. russkii, P. berolinensis, P.pseudo-simonii, P.pseudo-simonii×P.nigra,P. ussuriensis, P.stalintz,P.alba×P.berolinensis and P.simonii were extracted using the same condition. The chemical components of volatiles were analyzed using gas chromatography-mass spectrometry (GC-MS). The research found that the major components of the volatiles are aldehyde, ester, acid, hydrocarbon, and mainly acid, while, the content of other substances is lower, less other big molecule components such as naphthalene, quinine, azulene and ketone.There are more variety of special compounds in the barks of P.berolinensis and P.stalintz. The behavioral reactions of males and females X. rusticus to the volatiles, 100 Μl, of ten kinds of poplar barks to volatiles were tested respectively using Y-tube olfactometer. It showed that 54.17% of male X.rusticus choose P.pseudo-simonii, comparatively, 58.33% of females choose P.pseudo-simonii×P.nigra and 54.17% of female X. rusticus choose the votaliles of P.pseudo-simonii and P.berolinensis. ANOVA analysis showed that the difference among the percentages　of the male X.rusticus choosing the ten kinds of volatiles are not significant (P＞0.05), but the females shown the significant reaction differences to the different volatiles (P＜0.05).

Key words: Xylotrechus rusticus, Populus spp., CO₂ supercritical fluid extraction (SFE-CO₂), volatiles, behavioural reaction