Comparison of responses of ascospores and mycelium by ELISA with anti-mycelium and anti-ascospore antisera for the development of a method to detect Sclerotinia sclerotiorum on petals of oilseed rape.

摘要

Since S. sclerotiorum exists in two forms on petals, as ascospores and mycelium, the responses of anti-mycelium and anti-ascospore antisera against these two kinds of antigens were compared. Two anti-mycelium sera, Smy and Smy', were produced against mycelial soluble extracts at different concentrations (0.3 mg and 0.1 mg of protein/ml). Smy gave the greatest response level with 8 S. sclerotiorum mycelial extracts tested. It had a very superior level of recognition to that of anti-ascospore serum,Ssp, when mycelium was tested as antigen. In contrast, Ssp and Smy were equally reactive when exposed to ascospores but the sensitivity of the assay was low. For each antiserum, the solution from which ascospores had been removed reacted similarly to theoriginal suspension containing ascospores. A collection of fungi likely to be found on oilseed rape petals was examined. Cross-reactions were produced with both antisera, especially with Botrytis cinerea for which greater cross-reactivities were produced with Smy. The cross-absorption of antiserum Smy with a mycelial extract of B. cinerea considerably reduced this cross-reaction. The choice of antiserum for the development of a reliable detection system is discussed.