Abstract
The causal agent of Fusarium leaf spot of rice (Kasshokuhagare-byo) was identified as Fusarium nivale (pink snow mold) in 1970, however, there are still some objections. To clarify this problem zymograms of non-specific esterase and catalase excreted by the causal fungi were compared. A preliminary comparison of various formae speciales of F. oxysporum and F. solani showed that the zymograms are species specific and useful for identification and taxonomy of Fusarium species. The zymograms of the leaf spot of rice were strikingly different from those of F. nivale causing typical pink snow mold. Differences were also observed between F. nivale from pink snow mold and that from various graminaceous plants in summer. The significance of zymogram diversity in the taxonomy of Fusarium species and the classification of the leaf spot fungus of rice were discussed.