The Study On Volatiles Of Pinus Tabulaeformis And The Electrophysiological Response Of Female Dendrolimus Tabulaeformis Tsai Et Liu To Its Volatiles

In this paper, volatile organic compounds from Pinus tabulaeformis were collected using dynamic headspace collection methods and identified by gas chromatography/mass spectrometry(GC-MS). The forty compounds of healthy needles of needles of Pinus tabulaeformis were identified. The results indicated that terpenes and oxygenated volatile organic compounds were the dominant volatiles release from P. tabulaeformis. The relative amounts of monopene in the volatiles of the needles of Pinus tabulaeformis are 52.64%, and relative amounts of the oxygen containing compounds in the volatiles are 35.13%.The emission of major volatile organic compounds followed a diurnal cycle with release rates increased during the light period and decreased during the dark period. This inosculates with the pest activity disciplinarian of the natural enemy activity and shows the coordination evolution between the plant the phytophagy insect and the natural enemy.The result of volatile organic compounds from P. tabulaeformis indicated that different degrees damage considerably influenced the changes of induced volatile products from leaves. The relative percentages of most volatiles were higher than the healthy control Pinus besidesα- pinene in slightly artificially-damaged leaves; on the other hand, in serious artificially-damaged leaves, the relative percentage ofβ-myrcene was lower than the control, and others were higher than the healthy trees. In damaged P. massioniana, the induced-volatile organic compounds' changes only occurred on the variation of relative contents no new induced compounds were found so far.Electroantennograms were recorded from female Dendrolimus punctafus tabulaeformis Tsai et Liu to serial stimulus doses(50μl, 100μl, 400μl, 800μl, 1600μl,3200μl)offour monoterpene hydrocarbons ((+) -α-pinene,(-) -α- pinene,(-) -β- pinene,(+) -β- pinene) and the threshold were tested. Dose-response curves constructed from EAGsrevealed that the threshold of(-)-α- pinene was 1 600μl and the threshold of the other three chemicals were 800μl. The relative size of the electroantennogram response was higher for (+) -α-pinene compared to (-) -α-pinene ,indicating that greater affinity to receptor molecules for (+) -α-pinene at the level of the dendrites; On the contrary, response of the insects to the (-) form of theβ-pinene was higher than that to the (+) form, showing (+) -β- pinene does not bind as efficiently with the receptor molecules in many of the sensilla. Electroantennogram recording using mixtures of the enantiomers at saturating dose levels showed that the response to the mixture ofα- pinene was between the two forms ofα- pinene .It is showed that the two forms ofα-pinene were detected by the same receptor neurons, and the same to theβ- pinene. Discrimination between enantiomers by plant olfactory receptor neurons in the insects suggested that the enantiomeric ratios of volatile compounds may be important in host location by the D. punetafus tabulaeformis Tsai et Liu.The results of female D. punetafus tabulaeformis Tsai et Liu to the volatiles from the host plant and the non-host plant indicate that the response of the insects to the volatiles of P. tabulaeformis is higher than the response to the non-host plant volatiles.