The genes for seedling resistance to race 11, 17 and 34 were located through monosomic studies in the wheat varieties Lerma Rojo and Sonora 64. The resistance to race 11 was found to be controlled by a single dominant gene located on 2D together with minor genes for resistance on chromosomes 1D, 3B and 6D of Lerma Rojo. The inheritance of resistance to races 17 and 34 studied in Sonora cross was controlled by two pairs of independently inherited factors, one dominant and the other recessive together with few minor genes. The dominant gene for resistance to race 17 was located on 6B and the recessive gene on 3B. In case of race 34, the dominant gene for resistance was located on 6A, whereas the recessive gene was located on 1A. The minor genes for resistance were located on 1D in case of 17 and on 2B and 4B in case of race 34.
