Identification of Blast-Resistance Genes in Some Rice Varieties

Abstract

The identification of genes fcr blast resistance was carried out in M.M. 10, 65A 15 Fuji 120, BR No. I and Tsuyuake. The results indicated that M.M. 10 and 65A-15 had the genes Pi-z and Pi-b, respectively. Fuji 120 had an allele on the locus Pi-k. The gene Pi-m which had been found in Minehikari and was linked with Pi-k was not separated from the gene Pi-k in hybrid progenies of BR No. I and Tsuyuake with Shin 2-type varieties. This indicates the possibility that Pi-m was also located on the locus Pi-k. Therefore Pi-m and Pi-k were named Pi-k^m as an allele. The reaction of Fuji 120, Tsuyuake. Kusabue, K2 and K3 to many isolates collected during the past four years were compared. The results showed that reactions of Fuji 120 were very similar to those of K3. Therefore, the gene in Fuji 120 was considered to be Pi-k^h which was found in K3. A cornparison among reactions of K3, Mutsunishiki. Chugoku 31 and Dawn to the seven fungus strains suggested that Mutsunishiki which originated from a sister line of Fuji 120 and whose resistance gene was derived from a Vietna-mese variety. ChugokLt 31 whose resistance gene was introduced from an Indian variety and Dawn, a U.S. variety, have Pi-k^h