Journal of Forest Research

, Volume 1, Issue 4, pp 223–226 | Cite as

Responses of water-stressedPinus thunbergii to inoculation with avirulent pine wood nematode (Bursaphelenchus xylophilus): Water relations and xylem histology

  • Takefumi Ikeda
Original Articles


The effect of water-stress conditioning on water relations and histological features ofPinus thunbergii Parl. inoculated with avirulent isolate ofBursaphelenchus xylophilus (Steiner and Buhrer) Nickle, pine wood nematode, were investigated. Pines were kept under 8 days cycle of severe water stress. One-half of the water-stressed pines died as a result of infection by avirulent pine wood nematode and water stress tended to induce increased susceptibility and/or decreased resistance of pines to avirulent pine wood nematode. In dead pines, the water conducting function of xylem was lost, and all of the parenchyma cells died. In surviving pines, the xylem hydraulic conductivity and the xylem water content were significantly reduced (12 to 23% and 77 to 83%, respectively) compared to controls. Safranin dye perfusion of excised axis stem segments indicated that the water conductance was limited to the very narrow peripheral area of xylem. Embolism caused by cavitation in the tracheids occurred in the central part of xylem and in that dysfunctional region of the xylem the axial parenchyma cells surrounding the epithelial cells, and ray parenchyma cells partly degenerated but the epithelial cells survived. The disruption of tracheid shape observed in surviving pines indicates that avirulent pine wood nematode temporarily disturbed cell division of the cambium. Considering the differences in responses between dead pines and surviving pines after inoculation with avirulent pine wood nematode, the death of water-stressed pines apparently resulted from death of cells, in particular the vascular cambium and the loss of xylem hydraulic function by cavitation.

Key words

avirulent pine wood nematode embolism histology pine wilt disease water stress 


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Literature cited

  1. Bolla, R.I. and Tamura, H. (1989) Mating potential and chromosome number of some Japanese and U.S. populations of the pine wood nematode,Bursaphelenchus xylophilus. Jpn. J. Nematol. 19: 7–12.Google Scholar
  2. Bolla, R.I., Kozlowski, P., and Fitzsimmons, K. (1988) Carbohydrate catabolism in populations ofBursaphelenchus xylophilus andB. mucronatus. J. Nematol. 20: 252–259.Google Scholar
  3. Fukuda, K., Hogetsu, T., and Suzuki, K. (1992) Photosynthesis and water status of pine-wood nematode-infected pine seedlings. J. Jpn. For. Soc. 74: 1–8.Google Scholar
  4. Ikeda, T. and Kiyohara, T. (1995) Water relations, xylem embolism and histological features ofPinus thunbergii inoculated with virulent or avirulent pine wood nematodes,Bursaphelenchus xylophilus. J. Exp. Bot. 46: 441–449.Google Scholar
  5. Ikeda, T. and Suzaki, T. (1984) Distribution of xylem resistance to water flow in stems and branches of hardwood species. J. Jpn. For. Soc. 66: 229–236.Google Scholar
  6. Ikeda, T., Kiyohara, T., and Kusunoki, M. (1990) Changes in water status ofPinus thunbergii infected with species ofBursaphelenchus. J. Nematol. 22: 132–135.Google Scholar
  7. Ikeda, T., Toda, T., and Tajima, M. (1994) Histological responses of different resistant families ofPinus thunbergii andP. densiflora to an invasion of pine wood nematode. Ann. Phytopathol. Soc. Jpn. 60: 540–542 (in Japanese with English summary).Google Scholar
  8. Jarvis, P.G. (1975) Water transfer in plants.In Heat and mass transfer in the biosphere. de Vries, D.A. and van Alfen, N.K. (ed.), Scripta Book Co., Washington, D.C., 369–394.Google Scholar
  9. Kiyohara, T. (1984) Pine wilt resistance induced by prior inoculation with avirulent isolate ofBursaphelenchus xylophilus.In Proceedings of the U.S. Japan seminar. The resistance mechanisms of pines against pine wilt disease. Dropkin, V.H. (ed.), University of Missouri Press, Columbia, 178–187.Google Scholar
  10. Kiyohara, T. (1989) Etiological study of pine wilt disease. Bull. For. For. Prof. Res. Inst. 353: 127–176 (in Japanese with English summary).Google Scholar
  11. Kiyohara, T. and Bolla, R.I. (1990) Pathogenic variability among populations of the pinewood nematodes,Bursaphelenchus xylophilus. For. Sci. 36: 1061–1076.Google Scholar
  12. Kozlowski, T.T., Kramer, P.J., and Pallady, S.G. (1991) The physiological ecology of woody plants. Academic Press, San Diego, 18–30.Google Scholar
  13. Mamiya, Y. (1983) Pathology of the pine wilt disease caused byBursaphelenchus xylophilus. Ann. Rev. Phytopathol. 21: 201–220.Google Scholar
  14. Thorne, G. (1961) Principles of nematology. 553pp. McGraw-Hill Book Campany Inc., New York.Google Scholar

Copyright information

© The Japanese Forestry Society 1996

Authors and Affiliations

  • Takefumi Ikeda
    • 1
  1. 1.Kansai Research CenterForestry and Forest Products Research InstituteKyotoJapan

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