Gene Identification and Reaction of Rice Varieties to Korean and Philippine Races of Xanthomonas oryzae. pv. oryzae

Bacterial blight (BB) caused by Xanthomonas oryzae pv. Oryzae (Xoo) is one of the most serious diseases of rice. Ten races of the bacterium have been identif ied in the Philippines. Each race has specif ic virulence to

Bacterial blight （BB） caused by Xanthomonas oryzae pv. Oryzae （Xoo） is one of the most serious diseases of rice. Ten races of the bacterium have been identified in the Philippines. Each race has specific virulence to varieties with different resistance genes, showing a gene-for-gene relationship in the host-pathogen interaction （Lee et al., 2003）. So far, twenty-nine major genes have been identified （Lee et al., 1999）. Due to emergence of the new races and genetic vulnerability of resistant varieties, the spreading of bacterial blight disease occurrence is increasing now in all areas of Korea. This study was carried out to find the gene identification and reaction of rice varieties to Korean and Philippine races ofXanthomonas oryzae, pv. oryzae.