Abstract
Kiyosawa's differential varieties for rice blast races and IKEHASHI's set representing major types of indica rice varieties in IRRI were evaluated for ability of these varieties to differentiate Philippine fungus isolates. The results indicate that the KIYOSAWA's and IKEHASHI, s sets were not suitable for differentiating Philippine isolates, although the KIYOSAWA's differential varieties are suitable for differentiating Japanese isolates and have single genes for blast resistance. However, the KlYOSAWA's differential varieties may be tentatively useful to differentiate rice blast races in a country which does not have suitable differential varieties. Reactions of Tongil added in the tests supported the assumption that Tongil had Pi-a, Pi-b and Pi-t.
