VIEW ARTICLE

Postharvest Pathology and Mycotoxins

Ethylene Effects on In Vitro and In Vivo Growth of Certain Postharvest Fruit-Infecting Fungi. M. K. El-Kazzaz, Department of Pomology, University of California, Davis 95616, Current address: Department of Plant Pathology, Faculty of Agriculture, Tanta University, Kafr El-Sheikh, Egypt; N. F. Sommer(2), and A. A. Kader(3). (2)(3)Department of Pomology, University of California, Davis 95616. Phytopathology 73:998-1001. Accepted for publication 1 February 1983. Copyright 1983 The American Phytopathological Society. DOI: 10.1094/Phyto-73-998.

Exposure of certain postharvest fruit-infecting fungi (Alternaria alternata, Botrytis cinerea, Colletotrichum gloeosporioides, Monilinia fructicola, Penicillium digitatum, P. expansum, P. italicum, Rhizopus stolonifer, and Thielaviopsis paradoxa) to ethylene (C₂H₄) at 1, 10, 100, and 10³ μl/L of air stimulated germination of P. digitatum, P. italicum, and T. paradoxa and germ tube elongation of most of the tested fungi, but had little influence on their final growth rates at 20 C. Treatment with C₂H₄ up to 10³ μl/L of air increased the total dry weight of B. cinerea grown both in vitro and in vivo (the latter on strawberries, as determined by glucosamine content) after 4 days at 20 C. Glucosamine content of P. italicum grown in vitro and in vivo (the latter on oranges) also increased in response to similar exposure of fruits to C₂H₄. C₂H₄ did not affect lesion diameters on navel oranges inoculated with P. italicum before C₂H₄ exposure was initiated. However, similar oranges treated with C₂H₄ for 3 days at 20 C before inoculation with P. italicum became more resistant and developed smaller lesions.