Etiology of stipe necrosis of cultivated mushrooms (<em>Agaricus bosporus</em>) in Egypt

Internal stipe necrosis of cultivated button mushrooms (Agaricus bisporus) is caused by the bacterium Ewingella americana (Enterobacteriaceae), which is part of the endogenous bacterial population in mushroom sporocarp tissues. Isolation of the causal agent of stipe necrosis led to the recovery of t...

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Bibliographic Details
Main Authors: Adel MADBOULY, Einas EL-SHATOURY, Mohamed ABOUZEID
Format: Article
Language:English
Published: Firenze University Press 2014-04-01
Series:Phytopathologia Mediterranea
Subjects:
Online Access:https://oajournals.fupress.net/index.php/pm/article/view/5556
Description
Summary:Internal stipe necrosis of cultivated button mushrooms (Agaricus bisporus) is caused by the bacterium Ewingella americana (Enterobacteriaceae), which is part of the endogenous bacterial population in mushroom sporocarp tissues. Isolation of the causal agent of stipe necrosis led to the recovery of three bacterial morphotypes. Ewingella americana was isolated from 90% of mushroom samples showing mild stipe browning, while Pseudomonas fluorescens and P. tolaasii were also isolated. Inoculation with E. americana into button mushroom sporocarps yielded typical browning symptoms which were distinguishable from those of the bacterial soft rot. This bacterium was re-isolated and its identification was verified, thus fulfilling Koch’s postulates. However, inoculations with P. fluorescens and P. tolaasii caused no stipe browning. The strain identities were verified by biochemical identification and through analysis of their 16S rRNA gene sequences. This study has outlined the etiology of stipe necrosis of cultivated button mushroom in Egypt, and is the first report of E. americana in this country.
ISSN:0031-9465
1593-2095