BURSAPHELENCHUS-XYLOPHILUS INDUCED PINE WILT - FACTORS ASSOCIATED WITH RESISTANCE

We investigated factors affecting resistance of Pinus spp. to Bursaphelenchus xylophilus. Nematode migration and multiplication was inhibited in resistant P. taeda. As a consequence acceleration of monoterpene synthesis terminated, tracheid-cavitation did not become extensive, and xylem sap ascent was not significantly blocked. In P. strobus, inhibition of nematode activity was not as complete as in P. taeda, and temporal needle-wilting was seen on some branches. Although this suggest some blockage of xylem water conduction, we were unable to confirm development of cavitation induced by nematode activity. Beta-myrcene concentration in these species was not related to resistance.