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Biology of Pseudomonas cichorii in chrysanthemum 1
Author(s) -
JANSE J. D.
Publication year - 1987
Publication title -
eppo bulletin
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.327
H-Index - 36
eISSN - 1365-2338
pISSN - 0250-8052
DOI - 10.1111/j.1365-2338.1987.tb00045.x
Subject(s) - biology , inoculation , blight , pathogen , virulence , outbreak , horticulture , host (biology) , homogeneous , botany , veterinary medicine , microbiology and biotechnology , ecology , medicine , biochemistry , physics , virology , gene , thermodynamics
Since 1982, outbreaks of stem blight caused by Pseudomonas cichorii are sometimes found in greenhouse‐grown chrysanthemums in The Netherlands. In this study, 13 Dutch chrysanthemum isolates and, for comparison, six from other origins were biochemically, serologically and pathologically characterized. All isolates were biochemically homogeneous in most of some 40 tests. Different serotypes were observed, which were not host or virulence‐correlated. After inoculation into cut and potted chrysanthemum, endive and chicory, P. cichorii isolates were found to be non‐host‐specific. Isolates showed differences in virulence after inoculation into potted chrysanthemum. For five isolates, disease development at high humidity (85–95% RH, 18°C) was more than 100% greater than at low humidity (55–70% RH, 18°C). Using a selective medium and immunosorbent dilution plating (ISDP), P. cichorii could be isolated from symptomless leaves and soil from nurseries where the disease was observed and from soil of a disease‐free nursery. ISDP did not significantly increase the recovery of the pathogen. It was concluded that: (a) P. cichorii is an opportunistic pathogen; (b) epidemic infections of stem blight are due to a combination of high humidity, higher temperatures, high plant density and use of very susceptible cultivars; (c) control measures should concentrate on preventing this combination.