Resistance of three interspecific white pine hybrids to blister rust

Abstract

Three white pine hybrids exposed to infection by white pine blister rust (Cronartium ribicola Fischer) since 1946 have inherited the relative resistance of their parental species. The hybrids were produced from controlled pollinations in 1940 and 1941 at the Institute of Forest Genetics, Placerville, Calif. Twelve seedlings of each hybrid were planted in 1946 on a site near Rhododendron. Ore., where rust infection and growing conditions were severe. Concurrent tests at this locality showed the relative resistance of the parental species: Pinus monticola Dougl., very susceptible; P. strobus L., susceptible; and P. griffithii McClell., resistant (2). After 11 years of exposure, resistance of hybrids was directly related to resistance of parental species. By 1957 all Pinus monticola X strobus were dead; one tree of P. monticola X griffithii persisted; eight P. strobus X griffithii survived.

Citation

Callaham, R. Z. 1962. Resistance of three interspecific white pine hybrids to blister rust. Journal of Forestry, Vol. 60(6): p.