RESISTANCE GENE OF RICE CULTIVAR, TAICHUNG NATIVE-1 TO PHILIPPINE RACES OF BACTERIAL-BLIGHT PATHOGENS

In the inoculation tests on rice cultivars using Philippine races of bacterial blight (BB) caused by Xanthomonas campestris pv. oryzae, we found that Taichung Native 1 (TN1) was resistant only to race 5 (PXO112) and susceptible to races 1, 2, 3, 4, and 6. This kind of reaction pattern to BB pathogens has not been found in any other rice cultivar resistant to BB in Japan and at the International Rice Research Institute in the Philippines. Therefore, it was suggested that TN1 has a new gene for resistance to BB. The mode of inheritance of resistance in TN1 to race 5 was studied. The analysis of the Fl plants, the F2 populations, and the backcross progeny from the crosses between TN1 and susceptible cultivars revealed that the resistance of TN1 was controlled by a single dominant gene. Thus this new resistance gene was designated as Xa-14.