DETECTION OF CLAVIBACTER-MICHIGANENSIS SSP MICHIGANENSIS IN TOMATO SEEDS BY IMMUNOFLUORESCENCE MICROSCOPY AND DILUTION PLATING

Citation
Aajm. Franken et al., DETECTION OF CLAVIBACTER-MICHIGANENSIS SSP MICHIGANENSIS IN TOMATO SEEDS BY IMMUNOFLUORESCENCE MICROSCOPY AND DILUTION PLATING, Netherlands journal of plant pathology, 99(3), 1993, pp. 125-137
Citations number
26
Categorie Soggetti
Plant Sciences",Agriculture
ISSN journal
00282944
Volume
99
Issue
3
Year of publication
1993
Pages
125 - 137
Database
ISI
SICI code
0028-2944(1993)99:3<125:DOCSMI>2.0.ZU;2-O
Abstract
A method for detecting Clavibacter michiganensis ssp. michiganensis in tomato seeds was evaluated. The method is based on rapid screening of tomato seed lots using indirect immunofluorescence staining (IF), fol lowed by dilution plating of IF positive seed lots. Different polyclon al antisera, prepared against C. michiganensis ssp. michiganensis were tested for their specificity using IF. All strains of C. michiganensi s ssp. michiganensis tested reacted with the polyclonal antisera. Two of nine saprophytic isolates from tomato seeds were positive with the antisera as well as with the control normal serum, but cells of these isolates were distinct in shape from cells of C. michiganensis ssp. mi chiganensis. For extraction of the pathogen from the seed, seeds were either blended with a stomacher or soaked at 4-6-degrees-C. The stomac her method yielded more fluorescent cells in IF than 24 h soaking of s eed samples. However, soaking of seeds for 48 h generally yielded less saprophytes and overall higher numbers of C. michiganensis ssp. michi ganensis colonies in dilution plating when compared to blending by a s tomacher. SCM medium was generally more selective than KBT and modifie d CNS medium. However, the efficacy of the medium was dependent on the seed lot and/or extraction method used. Confirmation of suspected col onies with YDC (yeast-dextrose-carbonate medium), IF and a pathogenici ty test on tomato seedlings proved to be highly reliable (P > 0.95). F or routine testing of seed lots it is recommended to screen tomato see d lots after soaking seeds for 24 h at 4-6-degrees-C with IF, followed by plating of IF-positive seed lots on modified CNS and SCM after soa king seeds for an additional 24 h.