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Physiology and Biochemistry

Altered Pattern of Root Formation on Cuttings of Gynura aurantiaca Infected by Citrus Exocortis Viroid. Ricardo Flores, Instituto de Agroquímica y Tecnología de Alimentos (C.S.I.C.) Jaime Roig 11, Valencia 10, Spain; José-Luis Rodríguez, Departamento de Bioquímica, Facultad de Ciencias Biológicas, Burjasot, Valencia, Spain. Phytopathology 71:964-966. Accepted for publication 6 February 1981. Copyright 1981 The American Phytopathological Society. DOI: 10.1094/Phyto-71-964.

The ability of cuttings from healthy and citrus exocortis viroid (CEV)-infected Gynura aurantiaca plants to form roots was investigated. Roots began to develop 8–10 days and 18–32 days after excision on healthy and CEV-infected cuttings, respectively. It also was observed that the root system of healthy cuttings was composed of a larger number of roots than that of CEV-infected ones. The impaired ability of CEV-infected cuttings to form roots could be related to small amounts of an auxinlike substance(s) with an R_r similar to indoleacetic acid that was found to diffuse from apical buds of CEV-infected G. aurantiaca.