Abstract
Abnormal ascent of xylem-sap was investigated after the inoculation of Pinus thunbergii with Bursaphelenchus xylophilus, using acid-fuchsin solution injected into the bottom of trunks of standing trees at one week intervals prior to harvest. Results were considered in relation to decrease in xylem water content, anatomical changes, and increase of nematode number in the trees. When sap-flow was disturbed two weeks after nematode inoculation, the water content began to decrease, after which whitish streaks became conspicuous in the cross section of trunks very clearly bounded by the area stained with the dye. Tracheids in those areas showed “cavitation”, that is, the phenomenon that tracheids come to contain gas instead of water. Xylem-sap flow, which ascended in spiral direction in healthy trees, was disturbed by the blockage of flow at cavitated tracheids. Areas of cavitation gradually spread to cover the entire cross sectional surface. Anatomical changes in pine tissue and increase in nematode number were delayed until the fourth week when water contents of xylem decreased to about 30% of healthy trees. Necrosis of cambium and phloem seemed to be caused by water shortage at the adjacent part to cavitated tracheids. Water deficit induced by cavitation was judged to be a major factor of inducing lethality in pine trees. Because resin leakage from epithelium was restricted to very small areas, mechanical plugging of water flow by leaked resin did not appear to be a major factor in disease induction. Clear boundaries between the cavitation and dye-stained areas suggested that hydrophobic substances were incorporated in cavitation areas. Investigations on the causal factors of cavitation may be required to understand the mechanism of pathogenesis associated with nematode infection.
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Claims 7
Claim · model-written summary
Xylem water content of Pinus thunbergii began to decrease after nematode inoculation, relative to healthy trees.
- Taxon
- Pinus thunbergii
Pinus thunbergiie0 - Treatment
- nematode inoculatione1
- Interactor
- Bursaphelenchus xylophilus
Bursaphelenchus xylophiluse0pathogen - Outcome
- water contente1
- Direction
- decreasee1
- Comparator
- healthy treese3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Abnormal ascent of xylem-sap was investigated after the inoculation of Pinus thunbergii with Bursaphelenchus xylophilus”
e1“When sap-flow was disturbed two weeks after nematode inoculation, the water content began to decrease”
e3“Anatomical changes in pine tissue and increase in nematode number were delayed until the fourth week when water contents of xylem decreased to about 30% of healthy trees”
Claim · model-written summary
Tracheids in the affected areas of Pinus thunbergii showed cavitation, containing gas instead of water.
- Taxon
- Pinus thunbergiiPinus thunbergiie0
- Organ / stage
- Tracheidse2
- Outcome
- cavitatione2
- Qualifier
- the phenomenon that tracheids come to contain gas instead of watere2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Abnormal ascent of xylem-sap was investigated after the inoculation of Pinus thunbergii with Bursaphelenchus xylophilus”
e2“Tracheids in those areas showed “cavitation”, that is, the phenomenon that tracheids come to contain gas instead of water”
Claim · model-written summary
Anatomical changes and nematode number increase in Pinus thunbergii were delayed until the fourth week after inoculation.
- Taxon
- Pinus thunbergiiPinus thunbergiie0
- Outcome
- Anatomical changes in pine tissue and increase in nematode numbere3
- Qualifier
- delayed until the fourth weeke3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Abnormal ascent of xylem-sap was investigated after the inoculation of Pinus thunbergii with Bursaphelenchus xylophilus”
e3“Anatomical changes in pine tissue and increase in nematode number were delayed until the fourth week when water contents of xylem decreased to about 30% of healthy trees”
Claim · model-written summary
Water deficit induced by cavitation is judged a major factor in lethality of pine trees.
- Taxon
- Pinus thunbergiiPinus thunbergiie0
- Outcome
- lethalitye4
- Qualifier
- Water deficit induced by cavitatione4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Abnormal ascent of xylem-sap was investigated after the inoculation of Pinus thunbergii with Bursaphelenchus xylophilus”
e4“Water deficit induced by cavitation was judged to be a major factor of inducing lethality in pine trees”
Claim · model-written summary
Necrosis of cambium and phloem may be caused by water shortage next to cavitated tracheids.
- Taxon
- Pinus thunbergiiPinus thunbergiie0
- Outcome
- Necrosis of cambium and phloeme5
- Qualifier
- water shortage at the adjacent part to cavitated tracheidse5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Abnormal ascent of xylem-sap was investigated after the inoculation of Pinus thunbergii with Bursaphelenchus xylophilus”
e5“Necrosis of cambium and phloem seemed to be caused by water shortage at the adjacent part to cavitated tracheids”
Claim · model-written summary
Mechanical plugging of water flow by leaked resin does not appear to be a major factor in pine wilt disease induction.
- Taxon
- Pinus thunbergiiPinus thunbergiie0
- Outcome
- disease inductione6
- Qualifier
- mechanical plugging of water flow by leaked resin did not appear to be a major factore6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Abnormal ascent of xylem-sap was investigated after the inoculation of Pinus thunbergii with Bursaphelenchus xylophilus”
e6“Because resin leakage from epithelium was restricted to very small areas, mechanical plugging of water flow by leaked resin did not appear to be a major factor in disease induction”
Claim · model-written summary
Hydrophobic substances may have been incorporated in cavitation areas of Pinus thunbergii.
- Taxon
- Pinus thunbergiiPinus thunbergiie0
- Outcome
- hydrophobic substancese7
- Qualifier
- incorporated in cavitation arease7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Abnormal ascent of xylem-sap was investigated after the inoculation of Pinus thunbergii with Bursaphelenchus xylophilus”
e7“Clear boundaries between the cavitation and dye-stained areas suggested that hydrophobic substances were incorporated in cavitation areas”
The same questions in other papers
inoculation · Bursaphelenchus xylophilus · Pinus thunbergii (Japanese black pine)Positive and negative results
3 papers in the same direction as this paper · 1 in the opposite direction
- positive
- negative
- negative
1 paper more in this group
See all 5 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.