VIEW ARTICLE

Physiology and Biochemistry

Effect of Scar Skin and Dapple Apple Diseases on Certain Groups of Phenolic Compounds in Apple. M. C. Huang, Graduate research assistant, Department of Plant Pathology, University of Massachusetts, Amherst, MA 01003, Present address of senior author: Department of Biological Science, Southern Illinois University, Edwardsville, IL 62026; G. N. Agrios, professor of plant pathology, Department of Plant Pathology, University of Massachusetts, Amherst, MA 01003. Phytopathology 69:35-40. Accepted for publication 7 August 1978. Copyright 1979 The American Phytopathological Society. DOI: 10.1094/Phyto-69-35.

Scar skin and dapple apple are caused by graft-transmissible agents presumed but not yet proved to be viruses. In Red Delicious apple, scar skin results in consistently higher amounts of total phenols, flavonols, and chlorogenic acids but in lower amounts of anthocyanins. In Hyslop Crab apple, dapple apple appeared to have no significant effect on the levels of total phenols, flavonols, or chlorogenic acids, but resulted in markedly lower levels of anthocyanins. Comparison of the effects of these two diseases on phenolic metabolism with the symptoms of the diseases on the fruits indicates that changes in phenolic metabolism are associated with the events observed in development of symptoms.