Abstract: The variation relationships of neutral terpenoids (mainly sesquiterpenoids) were investigated through GC determination of the different resistant provenances (high resistance: H, middle resistance: M and low resistance: L) of Pinus massoniana after they were inoculated with Bursaphelenchus xylophilus (pinewood nematodes, PWN). The results showed that the inoculation led to increase of some components such as longifolene with the inoculated days in the H and M provenances, but led to decrease of some compounds such as trans-caryophyllene in all three provenances. The inoculation of PWN into the H provenance resulted in the decrease followed by the increase of the ratio of contents of longifolene and trans caryophyllene. However,the inoculation did not finally change the resistance of masson pine provenance, and the growth did not affect the resistance, too.

Key words: neutral terpenoids, pinewood nematode (PWN), resistance mechanism, resistant provenance of masson pine, pine wilt