Genetic characterization of Pyrenophora graminea isolates and the reactions of some barley cultivars to leaf stripe disease under greenhouse conditions

The genetic diversity of Pyrenophora graminea, the causal agent of barley leaf stripe disease, was characterized by restriction fragment length polymorphism (RFLP) of the rDNA internal transcribed spacer region and intersimple sequence repeat (ISSR) analysis. A total of 45 P. graminea isolates recovered from different geographic origins and barley cultivars or genotypes produced identical RFLP banding patterns with HinfI, MspI, Hin6I and BsuRI restriction enzymes. ISSR analysis indicated that there was little genetic variability among the isolates. A dendrogram based on Jaccard's coefficient separated the isolates into 4 clusters with 12% dissimilarity. In the dendrogram, the isolates collected from different geographic regions in Turkey were clustered separately from the Italian isolates. These results indicated that the Turkish isolates of P. graminea were genetically homogeneous and may be derived from a single gene pool. In addition, 13 isolates were tested for pathogenic variability on 48 barley cultivars. The cultivars Durusu, Balkan 96 (Igri), Cumra 2001 and Anadolu 98 were found to be resistant to all leaf stripe isolates.