VIEW ARTICLE

Cytology and Histology

Cell Necrosis and Fungus Content in Fusiform Rust-Infected Loblolly, Longleaf, and Slash Pine Seedlings. Charles H. Walkinshaw, Principal plant pathologist, U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station, P.O. Box 2008, GMF, Gulfport, MS 39503; Phytopathology 68:1705-1710. Accepted for publication 26 June 1978. Copyright © 1978 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-68-1705.

Galled seedlings of loblolly, longleaf, and slash pine contained necrotic areas that were positive for tannin. These areas contained rust hyphae that exhibited peroxidase activity. Cell necrosis and deposition of tannin in infected tissues of slash pine appeared to be a normal host reaction to the pathogen. Tannin accumulation does not seem to be responsible for fusiform rust resistance since it normally occurs in actively growing galls.