Evaluation of polyclonal-antibody-based immunoassays for detection of Sclerotinia sclerotiorum on canola petals, and prediction of stem rot.
The potential for using polyclonal-antibody-based immunoassays for detection of Sclerotinia sclerotiorum on canola petals as part of a disease prediction model was investigated. A commercial ELISA kit designed for Sclerotinia homoeocarpa was evaluated for specificity to S. sclerotiorum in comparison to other Sclerotinia spp., and known phyllosphere fungi. This polyclonal-antibody-based kit cross-reacted with antigens from other Sclerotinia spp., and fungi, and absorbance values obtained from S. sclerotiorum-infested canola petals were poorly correlated with percentages of infested petals as determined by plating on semi-selective medium, except when petals were incubated at high humidity for 24 h at 20 degrees C-22 degrees C prior to ELISA evaluation. Additional polyclonal antibodies were prepared from mycelial and semi-purified cell wall antigens, and these antibodies were more specific to S. sclerotiorum than the ELISA kit. However, absorbance values obtained from S. sclerotiorum-infested canola petals were poorly correlated with percentages of infested petals as determined by plating on semi-selective medium. The results are discussed in relation to the use of polyclonal-antibody-based immunoassays for the prediction of epidemics or crop risk from sclerotinia stem rot of canola.
Bom
M
M
Department of Environmental Biology, University of Guelph, ON, Canada.
Boland
G J
GJ
D000818:Animals; D000908:Antibodies, Fungal / Q000276:immunology*; D000946:Antigens, Fungal / Q000032:analysis / Q000276:immunology; D001203:Ascomycota / Q000276:immunology / Q000302:isolation & purification*; D001937:Brassica / Q000382:microbiology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D007118:Immunoassay; D010935:Plant Diseases / Q000382:microbiology*; D011817:Rabbits
D000908:Antibodies, Fungal; D000946:Antigens, Fungal