VIEW ARTICLE

Stabilization of Conidium Morphology in Cultures of Alternaria longipes. E. K. Sobers, Associate Professor of Plant Pathology, University of Georgia College of Agriculture Experiment Stations, Coastal Plain Station, Tifton 31794; B. Doupnik, Jr., Assistant Professor of Plant Pathology, University of Nebraska, South Central Station, Clay Center 68933. Phytopathology 63:191-192. Accepted for publication 25 July 1972. DOI: 10.1094/Phyto-63-191.

Five of 58 isolates of Alternaria longipes pathogenic to tobacco retained their morphological identity and pathogenicity after 4 to 5 years in culture. Conidia produced by most of the remaining 53 isolates changed from the long, wide body (39.1 × 15.2 µ), and long-beaked (20.6 µ) type exhibited by pathogenic isolates, to type II conidia with short, narrow bodies (25.3 × 10.8 µ), and short beaks (5.9 µ). The majority of 79 isolates that were initially nonpathogenic exhibited a similar change in morphology to type II conidia. It is assumed that at least in culture, type II conidia represent the most stable form of A. longipes.