Microsatellite analysis of Puccinia triticina from Triticum and Aegilops hosts

Genetic variation between different populations of Puccinia triticina from Russia and Kazakhstan was evaluated, based on 18 simple sequence repeat (SSR) markers. Seventeen collections of P. triticina (181 single-uredinial isolates, in total) obtained from 15 different host species belonging to Aegilops and Triticum were included in the study. All single-uredinial isolates were obtained from naturally infected plants in experimental fields in Dagestan (Caucasus region of Russia), Novosibirsk (West Siberian region of Russia) and Shortandy (Northern Kazakhstan). Regional differentiation of P. triticina SSR genotypes was detected. Collections from host plants with the same ploidy and/or genetically similar background were genetically similar. Collections from the hexaploid species in Dagestan were highly similar to those from common wheat. Collections from tetraploid species T. aethiopiсum, T. turaniсum, T. dicoccum (genome BВA^uA^u) from Dagestan were moderately different from the collections originated from the hexaploid species. Puccinia triticina from Ae. crassa (D^cD^cMM) collected in Dagestan was genetically similar to populations from common wheat and other hexaploid species. Collections from Ae. tauschii (2n = 2× = 14) were significantly different from those obtained from tetraploid (2n = 4× =28) and hexaploid (2n = 6× =42) host species collected on the experimental field in Dagestan. SSR genotypes of P. triticina isolates from T. durum in Kazakhstan were highly dissimilar to those sampled from all other hosts. A low association was established between the SSR genotypes of P. triticina identified in the present study and the virulence phenotypes for the same set of collections, as observed in a previous study.