Serological detection and identification of rice blast

Monoclonal antibodies (MAbs) useful in the serological detection and identification of rice blast were produced by hybridoma cells formed from fusions of myeloma cells with splenocytes from BALB/c mice immunized with an extract of a liquid culture fluid of an isolate of Pyricularia grisea race IB-49. These MAbs reacted similarly with the antigens in various serological techniques used, and did not cross react with any unrelated fungal isolates representing 11 genera, but reacted positively with all 20 races or isolates of P. grisea. The MAbs could detect homologous antigen at about 60 ng fungal protein/ml and a 5-fold dilution of the extracts of infected rice tissue by ELISA. In accordance with another embodiment of the present invention, hybridoma lines secreting antibodies positive for the immunogen and negative for healthy rice tissue were selected from three independent fusions of NS-1 myeloma cells with splenocytes from mice immunized with crushed conidial suspensions of P. grisea race IB-49. MAbs secreted from cell line 4G11, deposited with ATCC as HB11178, reacted strongly with conidial antigen. In cross-reaction tests with ELISA, MAb 4G11 reacted negatively with isolates representing 11 fungal genera and reacted positively with 11 and 12 isolates of P. grisea in ELISA and IFA, respectively. MAb 4G11 could detect homologous conidial antigen at 14-70 ng/ml, 10-20 conidia/well, and the fungal antigen in infected rice tissue in ELISA