VIEW ARTICLE

Genetics

Genetics of Bacterial Blight Resistance in a Breeding Line of Rice. A. Yoshimura, Research fellow, The International Rice Research Institute (IRRI), Los Baņos, Laguna, Philippines; T. W. Mew(2), G. S. Khush(3), and T. Omura(4). (2)(3)Plant pathologist, and plant breeder, respectively, The International Rice Research Institute (IRRI), Los Baņos, Laguna, Philippines; (4)Professor of plant breeding, Faculty of Agriculture, Kyushu University, Fukuoka, Japan. Phytopathology 74:773-777. Accepted for publication 20 January 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/Phyto-74-773.

The genetics of resistance in rice breeding line IR1545-339 to strains of four races of Xanthomonas campestris pv. oryzae in the Philippines was studied. The analysis of F₁ and F₂ populations from the cross of IR 1545-339 with susceptible cultivar TN1 demonstrated that recessive gene xa-5 conferred the high resistance of IR1545-339 to races 1, 2, and 3. The moderate resistance of IR1545-339 to a strain of race 4, which is characterized by slow lesion development, also appeared to be governed by xa-5. Trisomic analysis revealed that xa-5 is located on chromosome 2 as designated by Nishimura.