Fire Blight Disease Caused by &amp;lt;i&amp;gt;Erwinia amylovora&amp;lt;/i&amp;gt; on &amp;lt;i&amp;gt;Rosaceae&amp;lt;/i&amp;gt; Plants in Kyrgyzstan and Biological Agents to Control This Disease

Tinatin Doolotkeldieva,Saykal Bobusheva

doi:10.4236/aim.2016.611080

Abstract

Erwinia amylovora species were isolated from the blossoms, exudates, infected fruits, leaves and bent branches of diseased apple, pear and hawthorn trees, selected in the Chy, Osh and Jalal Abad regions. Biochemical and pathogenicity tests, alongside PCR analyses, were conducted to identify the local isolates of Erwinia amylovora. The alternative antagonistic microorganisms which combat bacterium E. amylovora were tested within in vitro and in vivo conditions. The results revealed the ability of Streptomyces antagonistic bacteria to decrease fire blight severity on pear and apple trees during the first stage of the fire blight disease in leaf tissues. Streptomyces strain C1-4 suppressed E. amylovora disease symptoms in the leaf tissues and excised apple and pear shoots. The incidence of fire blight on leaves was reduced by about 70% with two applications of bacterial antagonists. Further studies at different locations in Kyrgyzstan, using large scale application, would allow for stronger recommendations to be made, including studies and recommendations on their ability to prevent disease and to use them as main components in an integrated pest management program.

Highlights

Fire blight, caused by the bacterium Erwinia amylovora, is an important disease affecting most types of Rosaceae plant and represents an enormous threat to fruit cultivation in many parts of the world
The results revealed the ability of Streptomyces antagonistic bacteria to decrease fire blight severity on pear and apple trees during the first stage of the fire blight disease in leaf tissues
The number of colony forming units (CFU) of the pathogen on the medium was determined and the results show that the number of bacterial CFU increased daily

Summary

Introduction

Fire blight, caused by the bacterium Erwinia amylovora, is an important disease affecting most types of Rosaceae plant and represents an enormous threat to fruit cultivation in many parts of the world. The host Rosaceous trees for Erwinia amylovora are pear, apple, quince, loquat, ornamental and wild plants According to EPPO (2012), E. amylovora is currently present in more than 50 countries worldwide [1]. It is a complex disease which passes its entire cycle in close association with the host plant, where it is able to infect fruit, leaf, shoot and flower tissue. In all cases, cause sticky, amber-like drops of ooze, composed of viable bacteria in a polysaccharide matrix, to be formed on the blighted plant parts [2]

Objectives

Methods

Results

Conclusion