Article

 

Phytophthora ramorum colonizes tanoak xylem and is associated with reduced stem water transport Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/articles/1544bp669

Descriptions

Attribute NameValues
Creator
Abstract
  • Isolation, detection with diagnostic polymerase chain reaction (PCR), and microscopy demonstrated the presence of Phytophthora ramorum in the sapwood of mature, naturally infected tanoak (Lithocarpus densiflorus) trees. The pathogen was strongly associated with discolored sapwood (P < 0.001), and was recovered or detected from 83% of discolored sapwood tissue samples. Hyphae were abundant in the xylem vessels, ray parenchyma, and fiber tracheids. Chlamydospores were observed in the vessels. Studies of log inoculation indicated that P. ramorum readily colonized sapwood from inoculum placed in the bark, cambium, or sapwood. After 8 weeks, radial spread of P. ramorum in sapwood averaged 3.0 to 3.3 cm and axial spread averaged 12.4 to 18.8 cm. A field study was conducted to determine if trees with infected xylem had reduced sap flux and reduced specific conductivity relative to noninfected control trees. Sap flux was monitored with heat-diffusion sensors and tissue samples near the sensors were subsequently tested for P. ramorum. Adjacent wood sections were excised and specific conductivity measured. Both midday sap flux and specific conductivity were significantly reduced in infected trees versus noninfected control trees. Vessel diameter distributions did not differ significantly among the two treatments, but tyloses were more abundant in infected than in noninfected trees. Implications for pathogenesis, symptomology, and epidemiology are discussed.
Resource Type
Date Available
Date Issued
Citation
  • Parke, J. L., Oh, E., Voelker, S., Hansen, E. M., Buckles, G., and Lachenbruch, B. 2007. Phytophthora ramorum colonizes tanoak xylem and is associated with reduced stem water transport. Phytopathology 97:1558-1567.
Academic Affiliation
Series
Keyword
Rights Statement
Publisher
Language
Replaces
Additional Information
  • description.provenance : Submitted by Alexa Pinckard (pinckara@onid.orst.edu) on 2009-12-22T23:58:28Z No. of bitstreams: 1 Parke_07_Phytopath_SODks.pdf: 707239 bytes, checksum: 8ad93b05b232ac0959883b8ae635a666 (MD5)
  • description.provenance : Made available in DSpace on 2009-12-28T18:52:13Z (GMT). No. of bitstreams: 1 Parke_07_Phytopath_SODks.pdf: 707239 bytes, checksum: 8ad93b05b232ac0959883b8ae635a666 (MD5) Previous issue date: 2007
  • description.provenance : Approved for entry into archive by Caryn Davis(caryn.davis@oregonstate.edu) on 2009-12-28T18:52:13Z (GMT) No. of bitstreams: 1 Parke_07_Phytopath_SODks.pdf: 707239 bytes, checksum: 8ad93b05b232ac0959883b8ae635a666 (MD5)

Relationships

Parents:

This work has no parents.

Items