Division of Genetics, Indian Agricultural Research Institute, New Delhi
The gene conditioning resistance to race 42 and its biotype 42B of black rust were located in the variety Sonora 64 through monosomic analysis. The resistance to race 42 was conditioned by two pairs of dominant duplicate factors located on chromosomes 6A and 1D. A single pair of dominant factor for biotype 42B was located on 6A, together with minor genes on two other chromosomes 1D and 6D.
