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Etiology

Corky Stunt: A Genetic Disease of Tomato. W. R. Stevenson, Assistant Professor of Plant Pathology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907; E. C. Tigchelaar(2), and A. O. Jackson(3). (2)Associate Professor of Horticulture, Department of Horticulture, Purdue University, West Lafayette, Indiana 47907; (3)Assistant Professor of Plant Pathology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907. Phytopathology 66:132-135. Accepted for publication 7 August 1975. DOI: 10.1094/Phyto-66-132.

Diagnostic symptoms of corky stunt, a seed-transmitted disease of the tomato cultivar Chico III, and the influence of temperature and light intensity on symptom expression are described. Symptoms include shortened internodes, proliferated axillary buds, malformed petioles, roughened lower petiole surfaces, malformed fruit, and corked fruit. Symptoms were most severe, and frequency of symptom expression was highest, at 22.5 C and 43-49 klx with a 16-hour photoperiod. No pathogenic microorganisms were observed in diseased plants, and the disorder was not transmitted mechanically or by grafting. The disease was shown to be controlled by a single recessive gene designated cst. A seedling assay technique was developed that used environmentally controlled growth chambers at 22.5 C and 43-49 klx with a 16-hour photoperiod.