1996 Volume 62 Issue 6 Pages 554-558
The occurrence of cavitation in Bursaphelenchus xylophilus-inoculated Pinus thunbergii was evaluated by analyzing acoustic emissions and water status in pine saplings. As determined from changes in the minimum xylem pressure potential, pine wilt disease development occurred in two stages. A small amount of cavitation occurred during the latter half of the first stage of disease development. As the infection progressed, cavitation increased. The occurrence of cavitation was greater after B. xylophilus inoculation when the xylem pressure potential was constant. The presence of B. xylophilus in pine increased the plant's potential for cavitation. In the second stage of disease development, a large increase in cavitations in the tracheids led to catastrophic destruction of the water conducting pathway. These findings support the idea of “runaway embolism” having a major role in mechanism of induction of pine wilt disease.
