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Erwinia pyrifoliae , an Erwinia species different from Erwinia amylovora , causes a necrotic disease of Asian pear trees
Author(s) -
Seong−Lyul Rhim,
Beate Völksch,
Louis Gardan,
J.P. Paulin,
C. Langlotz,
W. S. Kim,
Klaus Geider
Publication year - 1999
Publication title -
plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.928
H-Index - 85
eISSN - 1365-3059
pISSN - 0032-0862
DOI - 10.1046/j.1365-3059.1999.00376.x
Subject(s) - erwinia , biology , fire blight , pear , pyrus communis , botany , pathogen , microbiology and biotechnology , bacteria , malus , genetics
Bacteria from necrotic branches of Asian pear trees ( Pyrus pyrifolia ) in Korea were consistently isolated as white colonies on nutrient agar and formed mucoid, slightly yellow colonies on a minimal medium with copper sulphate. Isolates with this colony morphology were studied in a series of microbiological, molecular and pathological tests. Most isolates allowed the verification of Koch's postulate on P. pyrifolia seedlings and on slices from immature pear ( Pyrus communis ) fruits and were also positive in hypersensitivity tests on tobacco leaves. They showed characteristics common to species in the genus Erwinia , but were different from Erwinia amylovora , the agent of fire blight. A relationship between the novel pathogen and E. amylovora was found in microbiological and serological tests. Both organisms had similar but not identical protein patterns in 2‐D gel electrophoresis, and in growth morphology the new pathogen produced colonies on MM2 Cu medium that were mucoid and slightly yellow, compared with the clearly yellow colonies of E. amylovora . No similarity was found in the plasmid profiles, and consequently no PCR signal was obtained with primers from the E. amylovora plasmid pEA29. REP‐PCR also produced bands differing for the two organisms.