Interactions of Ethylene with Citrus Stem-End Rot Caused by<i>Diplodia natalensis</i>

G. Eldon Brown

Phytopathology · 1993 · 45 citations · 0 references

Concepts

Abstract

Ethylene treatment of citrus fruit to improve rind color (degreening) significantly enhances the incidence of stem-end rot caused by Diplodia natalensis and stimulates disease development. In an effort to identify the role of excessive exogenous ethylene in pathogenesis, tissue exposed to different ethylene and air atmospheres was taken from the base of citrus fruit adjacent to the abscission area at the point of fungal ingress and examined for the presence of fungal inhibitors and lignin. The major inhibitor, identified as scoparone (6,7-dimethoxycoumarin), accumulated most extensively in tissue taken from asymptomatic fruit receiving either high ethylene treatments (55 μl L -1 ) followed by low inoculum levels, or low ethylene treatments (2 μl L -1 ) followed by high inoculum levels [...]