Differential Resistance to Entomosporium Leafspot Disease and Hydrogen Cyanide Potential in Photinia
Photinia serrulata Lindl., P. glabra (Thunb. ex J.A. Murr.) Maxim., and two of their progeny, P. x fraseri Dress. ‘Birmingham’ and ‘Kentucky’ were screened for susceptibility to Entomosporium leafspot and for hydrogen cyanide potential using detached leaf assays. Photinia serrulata was least susceptible to the fungus, while P. x fraseri ‘Birmingham’ and P. glabra were most susceptible. Young leaves were much more susceptible than mature leaves in all taxa except P. glabra, which was found to be acyanogenic. Although distinct differences in hydrogen cyanide potential occurred among the clones, a direct correlation to disease susceptibility was not indicated.Abstract
Contributor Notes
1This project was partially funded by a grant from The Horticultural Research Institute, 1250 I Street, N.W., Suite 500, Washington, DC50005. We thank Ruth Dix for collecting inoculum and assisting in disease screening assays; Louise Riedel for assistance in HCN assays, and John C. Knowlton, III, Lázió Csiba, and Johann Klodzen for additional technical assistance. We appreciate the review comments made by Drs. Gary Watson and Charles Wilson.
2Research Plant Pathologist, The Morton Arboretum, Route 53, Lisle, IL 60532.
3Research Horticulturist, Floral and Nursery Plants Research Unit, U.S. National Arboretum, 3501 New York Ave., NE, Washington, DC 20002.
4Research Plant Geneticist, U.S.D.A. Forest Service, PNW Research Station, Corvallis, OR 97330.
5Professor, University of Georgia, Dept, of Horticulture, Athens, GA 30602.