Breakdown of major gene resistance to white pine blister rust in sugar pine at Mountain Home Demonstration State Forest: what are the implications?

Abstract

A virulent race of blister rust capable of neutralizing major gene resistance (MGR) in sugar pine made its first appearance nearly two decades ago at a test plantation of resistant sugar pines near Happy Camp, in northern California. Until this year (1996), it had not been found outside the very close neighborhood of this site. Its discovery last summer at Mountain Home Demonstration State Forest (see Adams, preceding paper) was thus alarming, because of the implications this held for federal, State, and industry selection programs based on deploying MGR in commercial plantations. Mountain Home is a strategic test site for assessing the efficacy of genetic resistance to control blister rust. The forest is well inventoried; the impact of blister rust has been closely observed and documented over the years; and selection and deployment of MGR has been implemented in a model program (Dulitz et al. 1996; Kinloch and Dulitz 1990). Was this an entirely new race? Or had the race at Happy Camp migrated over 500 miles south in one leap? Or had it also spread to other places along the way, as yet undetected?

Citation

Bohun B. Kinloch, Jr. 1996. Breakdown of major gene resistance to white pine blister rust in sugar pine at Mountain Home Demonstration State Forest: what are the implications?. In: Proceedings of the 45th Annual Meeting November 13-14, 1996, Sacramento, CA: p. 20-26