Forest Pathology (2017) 47 (5 - 12358)

M. Torii, Y. Matsuda and S. Ito (2017)
Comparisons of hyphal growth of Raffaelea quercivora among four Japanese Fagaceae species
Forest Pathology 47 (5 - 12358)
Abstract: Japanese oak wilt causes widespread oak mortality in Japan. Possible differences in susceptibility to the causal fungus, Raffaelea quercivora, may be due to vessel arrangements in host trees. To clarify whether constitutive defence mechanisms including vessel arrangements or induced defence mechanisms are the main determinants of host susceptibility, we inoculated the fungus into living seedlings or sterilized stem segments of four Japanese fagaceous species. In seedlings, water conductance was assessed with dye. In both seedlings and stem segments, hyphal growth was examined by fluorescence microscopy. In seedlings, the area of non-conductive sapwood in stem cross sections and hyphal growth differed significantly among species. In the susceptible species Quercus crispula and Quercus serrata, hyphal growth was significantly and positively correlated with the proportion of non-conductive sapwood. In stem segments, hyphal growth was not significantly different among species or between vessel arrangements and was similar to or greater than that in seedlings. These results suggest that the extent of sapwood colonization by R. quercivora could be used as a marker for susceptibility and that susceptibility is determined mainly by induced defence responses.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Masato Torii

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Dryadomyces quercivorus	Oak (Quercus)	Japan