title: Long-term impact of Ophiostoma novo-ulmi on leaf traits and transpiration of branches in the Dutch elm hybrid 'Dodoens'.
abstract: To better understand the long-term impact of Ophiostoma novo-ulmi Brasier on leaf physiology in 'Dodoens', a Dutch elm disease-tolerant hybrid, measurements of leaf area, leaf dry mass, petiole anatomy, petiole hydraulic conductivity, leaf and branch water potential, and branch sap flow were performed 3 years following an initial artificial inoculation. Although fungal hyphae were detected in fully expanded leaves, neither anatomical nor morphological traits were affected, indicating that there was no impact from the fungal hyphae on the leaves during leaf expansion. In contrast, however, infected trees showed both a lower transpiration rate of branches and a lower sap flow density. The long-term persistence of fungal hyphae inside vessels decreased the xylem hydraulic conductivity, but stomatal regulation of transpiration appeared to be unaffected as the leaf water potential in both infected and non-infected trees was similarly driven by the transpirational demands. Regardless of the fungal infection, leaves with a higher leaf mass per area ratio tended to have a higher leaf area-specific conductivity. Smaller leaves had an increased number of conduits with smaller diameters and thicker cell walls. Such a pattern could increase tolerance towards hydraulic dysfunction. Measurements of water potential and theoretical xylem conductivity revealed that petiole anatomy could predict the maximal transpiration rate. Three years following fungal inoculation, phenotypic expressions for the majority of the examined traits revealed a constitutive nature for their possible role in Dutch elm disease tolerance of 'Dodoens' trees.
authors: Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic roman.plichta@mendelu.cz.
authors: Roman
authors: R
authors: Plichta
authors: Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic.
authors: Josef
authors: J
authors: Urban
authors: Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic.
authors: Roman
authors: R
authors: Gebauer
authors: Department of Forest Protection and Wildlife Management, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic.
authors: Miloň
authors: M
authors: Dvořák
authors: Department of Phytology, Technical University in Zvolen, T. G. Masaryka 24, 960 53 Zvolen, Slovak Republic.
authors: Jaroslav
authors: J
authors: Ďurkovič
mesh_terms: D006824:Hybridization, Genetic; D055156:Ophiostoma / Q000502:physiology*; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology* / Q000502:physiology*; D018547:Plant Stems / Q000382:microbiology / Q000502:physiology*; D018526:Plant Transpiration / Q000502:physiology*; D025341:Principal Component Analysis; D019655:Quantitative Trait, Heritable; D013997:Time Factors; D034403:Ulmus / Q000382:microbiology / Q000502:physiology*; D014867:Water; D052584:Xylem / Q000382:microbiology
chemical_list: D014867:Water
keywords: Huber value; LMA; anatomy; petiole; potential transpiration; sap flow; water potential gradient