Forest Pathology (2002) 32, 123-134

A. Solla and L. Gil (2002)
Xylem vessel diameter as a factor in resistance of Ulmus minor to Ophiostoma novo-ulmi
Forest Pathology 32 (2), 123-134
Abstract: An investigation has been carried out to study the relationship between the susceptibility of Ulmus minor to Ophiostoma novo-ulmi and the diameter of its xylem vessels. Vessel diameters have been analysed in seven Spanish elms of known susceptibility, taking measurements from second and third year rings in 3-year-old branches. In the second year rings no relationship could be observed between the vessel diameters and the susceptibility of the trees. In the third year rings the mean diameter and the percentage of vessels larger than 100 µm were found to be significantly greater for the group of elms of high susceptibility. In the third year rings the vessel transectional area (VTA) and the theoretical hydraulic conductance (THC) were calculated. The decrease in VTA and THC became increasingly noticeable in the group of high susceptibility elms as vessels of larger diameter were excluded from the calculation. Xylem vessel diameters and the proportion of large vessels were correlated with the susceptibility of U. minor to Dutch elm disease. How these properties influence the dispersal of the fungus, the sap flow and the tree's ability to compartmentalize the disease is discussed.
(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): Luis Gil, Alejandro Solla

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Ophiostoma novo-ulmi	Elm (Ulmus)