VIEW ARTICLE

Resistance

Types of Resistance and Compatibility in Slash Pine Seedlings Infected by Cronartium fusiforme. Thomas Miller, Plant Pathologist, Southeastern Forest Experiment Station, Athens, Georgia 30602; E. B. Cowling(2), H. R. Powers, Jr.(3), and T. E. Blalock(4). (2)Professor of Plant Pathology and Forest Management, Department of Plant Pathology, North Carolina State University, Raleigh 27607; (3)(4)Principal Plant Pathologist, and Biological Technician, respectively, Southeastern Forest Experiment Station, Athens, Georgia 30602. Phytopathology 66:1229-1235. Accepted for publication 9 April 1976. Copyright © 1976 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-66-1229.

Seedlings of slash pine were inoculated with basidiospores of Cronartium fusiforme and examined periodically to determine symptoms and host responses to infection. Histological examination of inoculated seedlings provided evidence of four general types of host responses: (i) no penetration or infection; (ii) subliminal infection; (iii) three related types of hypersensitivity; and (iv) typical gall development. The hypersensitive responses effectively confined the fungus to reaction zones of necrotic cells.