Antimicrobial activity of extracts and select compounds in the heartwood of seven western conifers toward Phytophthora ramorum

Abstract

Previously, we demonstrated that wood chips, essential oil, and four individual compounds from Alaska yellow-cedar (Chamaecyparis nootkatensis [D. Don] Spach) heartwood strongly inhibit the germination f Phytophthora ramorum (Werres, de Cock, Man int Veld) zoospores or sporangia, and reduce hyphal growth in culture (Manter and others 2006). Essential oils from heartwood of incense cedar (Calocedrus decurrens [Torr.] Florin), western red cedar (Thuja plicata Donn ex D. Don), Port-Orford-cedar (Chamaecyparis lawsoniana [A. Murr.] Parl.), and western juniper (Juniperus occidentalis Hook.) were also tested and found to be equally active, but not investigated further until now. The objectives of this study were to: 1) test the procedure described by Kuhajek and others (2003) as a bioassay technique for P. ramorum; 2) use this bioassay with other individual compounds from yellow-cedar heartwood that were not previously tested for bioactivity toward P. ramorum; and 3) bioassay extracts and compounds from the heartwood of the other conifers with antimicrobial essential oils and compare their P. ramorum activity to the yellow-cedar constituents.

Parent Publication

• Proceedings of the sudden oak death third science symposium

Citation

Manter, Daniel K.; Kelsey, Rick G.; Karchesy, Joseph J. 2008. Antimicrobial activity of extracts and select compounds in the heartwood of seven western conifers toward Phytophthora ramorum. In: Frankel, Susan J.; Kliejunas, John T.; Palmieri, Katharine M., tech. coords. 2008. Proceedings of the sudden oak death third science symposium. Gen. Tech. Rep. PSW-GTR-214. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. pp. 375-378