AFLP fingerprinting of Chinese epidemic strains of Puccinia striiformis f. sp. tritici

Amplified fragment length polymorphism (AFLP) was used to fingerprint the epidemic strains CY25, CY27, CY28, CY29, CY30, CY31, Hy3, Hy7, Sy13 and a mutant strain WV-4 of P. striiformis f. sp. tritici, the pathogen of wheat stripe rust. The results showed that (i) genetic diversity existed in the pathogen populations, and based on it a dendrogram of these strains was constructed by unweighted pair-group mean average to demonstrate the relationships of the tested strains; (ii) no significant correlation between virulence of the pathogens and the polymorphism of DNA fingerprints was found; ( iii ) AFLP fingerprints showed higher polymorphism than that of the virulence variation; (iv) several new pathotypes identified might evolve independently of the reference strains identified before.