A first look at genetic variation in resistance to the root pathogen Phytophthora cinnamomi using a range-wide collection of Pacific madrone (Arbutus menziesii)
| Authors: | Marianne Elliott, Gary A. Chastaner, Annie DeBauw, Gil Dermott, Richard A. Sniezko |
| Year: | 2012 |
| Type: | General Technical Report |
| Station: | Pacific Southwest Research Station |
| Source: | In: Sniezko, Richard A.; Yanchuk, Alvin D.; Kliejunas, John T.; Palmieri, Katharine M.; Alexander, Janice M.; Frankel, Susan J., tech. coords. Proceedings of the fourth international workshop on the genetics of host-parasite interactions in forestry: Disease and insect resistance in forest trees. Gen. Tech. Rep. PSW-GTR-240. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture. pp. 290-294 |
Abstract
Phytophthora cinnamomi (Oomycetes) causes root disease and basal canker on a number of hardwood and conifer hosts, including Pacific madrone (Arbutus menziesii Pursh) (figs. 1, 2), a broadleaf evergreen species whose range extends from coastal British Columbia to southern California (Reeves 2007). Increasing mortality of Pacific madrone and the related shrub species manzanita (Arctostaphylos spp.) has been seen in California forests (Fichtner et al. 2009) in recent years.
Considered to be one of the world's most invasive species, P. cinnamomi is thought to have originated in southeast Asia and spread worldwide, causing decline in Australian eucalypt forests, crop losses on avocado in California and Europe, and on Christmas tree plantations in the southeast United States. It has a wide host range and infects many ornamental trees and shrubs in landscape plantings. In this situation, it is thought that the pathogen moves in contaminated soil on nursery stock (Smith 1988).