Growth of Cronartium ribicola in the absence of physical contact with its host

Abstract

Rust mycelia from tissue cultures infected with Cronartium ribicola J. C. Fisch. ex Rabenh. were grown on cellophane membranes in the absence of physical contact with host tissue. These membranes were in contact with agar media containing imbedded, actively growing western white pine (Pinus monticola Dougl.) tissue cultures. Identities of these cultures were verified by reestablishing infections in healthy host tissue cultures.