Virulence of Bursaphelenchus xylophilus
The pathophysiological changes of pine seedlings (Pinus thunbergii) inoculated with virulent and avirulent isolates of Bursaphelenchus xylophilus (EPPO A1 quarantine pest) and an isolate of B. mucronatus were investigated in Japan. As presented at the 6th International Congress of Plant Pathology in Montreal, all nematode isolates caused the same cytological changes of xylem parenchymatic cells and disfunction of water conduction (cavitation and embolism) in the inner part of the xylem. Only the virulent isolate caused enhanced ethylene production, cambial necrosis and embolism of the outermost xylem. In that case, xylem embolism resulted in the decrease in the leaf water potential, cessation of photosynthesis and finally the death of the seedlings. The authors concluded that virulence of B. xylophilus isolates depends on the ability to induce the cambial necrosis and embolism in the outermost xylem and that these internal symptoms are closely related to ethylene production.
Fukuda, K.; Suzuki, K. (1993) Pathophysiological changes of pine seedlings inoculated with virulent and avirulent isolates of pinewood nematodes.
Presentation at the 6th International Congress of Plant Pathology, Montreal, CA, 1993-07/08-27/06.