During the periodic purity checks of pathotypes 107-1(45R35=JCGPL) and 20(5R27=SGQPL) of Puccinia triticina in national repository at Shimla, India, mixtures of infection types were observed on the differential Lr3 and Lr15 , respectively. Single pustule isolations and further pure cultures in both the cases yielded new pathotypes designated as 57(45R39= KGTPL) and 20-2(57R27= SHKPL). Pathotype 57 was one step gain in virulence on Lr3 in 107-1 whereas 20-2 on Lr15 in mother culture of pathotype 20. The difference of virulence on one gene to each mother culture and their non occurrence in the field samples is indicative of mutation for virulence in situ . To ascertain the novelty of new pathotypes, detailed study on differentials, avirulence/virulence structure, DNA polymorphism using SSR markers, and other related information is presented in this publication. The new cultures are being maintained as PrtI 57 and PrtI 20-2 in the repository.