DEVELOPMENT OF MONOCLONAL ANTIBODY-BASED IMMUNOLOGICAL ASSAYS FOR THEDETECTION OF LIVE PROPAGULES OF RHIZOCTONIA-SOLANI IN SOIL

Mouse monoclonal antibodies (mAbs) and rabbit (polyclonal) antiserum w ere used to develop DIAGNOSTIC-ELISA, double-antibody-sandwich-ELISA ( DAS-ELISA), DIP-STICK and immunofluorescence colony staining immunoass ays for the specific detection of Rhizoctonia solani in soil. mAbs wer e raised against an anastomosis group 4 isolate of R. solani. Mice wer e immunized using either phosphate-buffered saline (PBS) suspensions o f lyophilized mycelium plus Quil A adjuvant, or with a solubilized ace tone precipitate prepared from cell-free surface washings from solid s lant cultures. Polyclonal antisera were raised in rabbits using PBS su spensions of lyophilized mycelium and Quil A adjuvant. Hybridoma super natants and rabbit antisera were screened by ELISA. Four of the cell l ines raised produced mAbs that were species-specific. They recognized antigens from R. solani by ELISA and immunofluorescence, but not other related or unrelated species of soil-borne fungi. The remaining cell line produced mabs that cross-reacted slightly, by ELISA, with antigen s from R. cerealis. These mAbs did not recognize R. cerealis by immuno fluorescence, or other related or unrelated soil-borne fungi, by ELISA .