Wheat Breeding Substation, I.A.R.I., Simla
The resistance of La Prevision to race 13 of Puccinia glumarum in its cross with Ridley was seen to be controlled by a single pair of dominant genes. In the cross, Frondoso X N.P. 770, resistance to this race was due to a single pair of recessive genes. In the cross, Cometa Klein x N.P. 770, the resistance of the Cometa Klein to race 13 was found to be governed by two pairs of complementary genes contributed by this parent. The resistance of La Prevision in its cross with N.P. 770 was due to the presence of a dominant gene, the expression which was however inhibited by a dominant epistatic gene for susceptibility contributed by the susceptible parent N.P. 770.
The resistance of Frontiera to race H of yellow rust in the cross with N.P. 770 was due to the action of duplicate factors, resistance behaving as the double recessive. However, the resistance of Cometa Klein to this race in its cross with N.P. 770, like that to race 13, was due to the complementary action of two genes present in this variety. The available evidence, however, showed that at least one of the genes involved in the resistance of Cometa Klein to these two races was not the same.
