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Resistance

Association of Suberin Formation in Uninoculated Wounds with Susceptibility to Leucostoma cincta and L. persoonii in Various Peach Cultivars. A. R. Biggs, Research scientist, Agriculture Canada, Research Station, Vineland Station, Ontario, Canada L0R 2E0; N. W. Miles, Research scientist, Horticultural Research Institute of Ontario, Vineland Station, Ontario, Canada L0R 2E0 Phytopathology 78:1070-1074. Accepted for publication 7 March 1988. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1988. DOI: 10.1094/Phyto-78-1070.

Branches of field-grown peach cultivars were mechanically wounded and sampled for histological study after 0, 3, 7, 10, 14, and 17 days. Cell counts and tissue thickness measurements were used to determine the extent of formation of ligno-suberized boundary tissue and suberized wound periderm. Suberin autofluorescence intensity also was measured with a microscope equipped with a photometer/fluorometer. The experiments were conducted twice at two sites from 1985 to 1987 and included wound series from the months of April, May, June, July, September, October, and November. Cultivars were ranked after each wound series according to the degree of formation of wound tissues or intensity of suberin autofluorescence. These ranks were compared to cultivar disease susceptibility ranks, based on field performance history, using Spearman’s rank correlation test. There were no consistent relationships between relative susceptibility to disease and phellem cell numbers or suberized tissue thickness. However, the rate of suberin accumulation during May and June was correlated in both years with the known relative susceptibility of the cultivars to the peach canker fungi.