USDA Forest Service

Pacific Southwest Research Station


Pacific Southwest Research Station
800 Buchanan Street
Albany, CA 94710-0011

(510) 559-6300

United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Research Topics Forest Genetics

Virulence in C. ribicola
Sugar pines with MGR that resisted early waves of infection for 14 years in a test plantation suddenly developed multiple infections from a new and virulent race of blister rust. Happy Camp, Siskyou Mountains California

Mixed resistant (HR) and susceptible (yellow) needle spot phenotypes on sugar pine with MGR.
(Spots are counted before they coalesce). Inoculum is from Thompson Ridge (TR).
virulent symptoms on needles
Frequency of vcr1 is determined by the proportion of total spots that are yellow.
Specificity of genetic interactions amoung major genes in the white pine/blister rust pathosystem.
MGR in western whie pine is also neutralized by a virulent race. However, this race has no affect on MGR in sugar pine, and the race neutralizing MGR in sugar pine has no affect on MGR in western white pine. This is typical of gene-for-gene systems.
Last Modified: Feb 25, 2011 04:15:23 PM