Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Methods were developed to obtain antigens from mycelium of species and races of Pyricularia. Antisera were developed against five test isolates off. oryzae and f· grisea. Conidia-agglutination tests and precipitin tests were developed for visualization of antigen­ antibody reactions using fungal antigens. Comparison of the irmruno­ diffusion and irrrmmoelectrophoresis reactions among species and races of Pyricularia indicated that all of the isolates tested were closely related, with several antigens in common, but also with specific antigens. Comparison of zymograms of protein bands from Pyricularia isolates separated by disc-gel electrophoresic; also showed similarities ..od differences in soluble proteins among tlw isolates. All tested isolates contained at least five major proteins in corrrnon. Using the technique of cross-adsorption it was demonstrated that f. grisea isolates from ryegrass and St. Augustinegrass were closely related antigenically and could bP differentiated from f. oryzae isolates IB-54, ID-13, and IB-49 serologically. Specific antisera were developed for two isolates indicating the feasibility of developing species or race specific antisera. In these studies, f. oryzae and f. grisea isolatea were found to have several antigens and proteins in connon. The antigen and protein differences among isolates within the f. grisea and P. oryzae groups were about the same as differences between P. grisea and P. oryzae isolatPs.