National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
Bacterial blight, caused by Xanthomonas oryzae pv. oryzae, is a serious disease of rice worldwide. A new dominant gene for bacterial blight resistance in rice, Xa25(t), was identified from Minghui 63, a restorer line for a number of rice hybrids that are widely cultivated in China. This gene conferred resistance to Philippine race 9 (PXO339) of X. oryzae pv. oryzae in both seedling and adult stages. It was mapped to the centromeric region of chromosome 12, 2.5 cM from a disease resistance gene-homologous sequence, NBS109, and 7.3 cM from a restriction fragment length polymorphism marker, G1314. The genomic location of this gene is similar to the previously identified blast resistance genes, Pi-ta and Pi-ta2.