Breeding Efforts with Eastern White Pine (<i>Pinus strobus L.</i>)for Resistance to Blister Rust (<i>Cronartium ribicola</i>)
Tami Rahkola
Abstract
Eastern white pine, Pinus strobus L., is native to North America, and is susceptible to attack by the blister rust, Cronartium ribicola J.C. Fischer in Rabenhorst, a fungus native to Asia. The pines in Eurasia have some resistance to this fungus through constant exposure, and the ensuing molecular arms race. The pines in North America descended separately from their Eurasian relatives, and do not possess the same resistance. In the early 20th century, some North American pines were found growing amongst infected neighbors. These trees and their clones have since been used for both molecular investigations, and intraspecific breeding programs in the search for natural resistance. When intraspecific programs proved less than successful in other countries, they turned to interspecific efforts. These programs have had success with crossing eastern white pine to the Himalayan blue pine, to increase resistance, while also maintaining the growth characteristics of eastern white pine.
