Increase of Disease Resistance in Celery Cultivars by Regeneration of Whole Plants from Cell Suspension Cultures. J. C. Wright, Former Graduate Research Assistant, Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824. M. L. Lacy, Professor, Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824. Plant Dis. 72:256-259. Accepted for publication 11 October 1987. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0256.

Callus cultures started from axillary buds of celery cultivars Florida 683 and Tall Utah 52-70 HK were used to initiate shaken liquid cultures of single plant cells and cell clumps. Whole plants (somaclones) regenerated from embryoids formed in shaken cultures were screened in the greenhouse for reaction to three fungal and one bacterial pathogen of celery: Septoria apiicola (late blight), Cercospora apii (early blight), Fusarium oxysporum f. sp. apii (Fusarium yellows), and Pseudomonas cichorii (bacterial blight). Regenerated plants varied from highly susceptible to highly resistant to all four pathogens, whereas parent plants of Florida 683 were uniformly highly susceptible to all pathogens. Parent plants of Tall Utah 52-70 HK were moderately resistant to the Fusarium yellows pathogen and highly susceptible to the remaining pathogens. Resistance to a given pathogen appeared to arise independently from resistance to other pathogens, since plants were rarely found with high resistance to two or more pathogens. This technique may become an important way of introducing disease resistance into susceptible cultivars of celery.