Powdery mildew (PM) is a common disease caused by Blumeria graminis, which affects cereals and has recently adapted to triticale. Adult‐plant resistance (APR) genes provide durable protection of crops from the disease. Quantitative trait loci corresponding to the APR effects were mapped in an F2 population of “Lamberto” (susceptible) × “Moderto” (resistant). A genetic map of winter triticale was constructed based on the segregation of 863 DArT, 38 microsatellite and 10 resistance gene analogue markers. Composite interval mapping (CIM) was applied to identify three QTLs for maximum disease severity (MDS) and two for the area under disease progress curve (AUDPC) conferring resistance to the powdery mildew on chromosomes: 6A, 7A, 1B and 4R. The 39% variation in AUDPC was explained by the main QTL localised on chromosome 4R. Genes coding TRIUR3 proteins, serine/threonine protein kinase and cell wall associated kinases were localised in silico within the QTL and alternative DNA markers were proposed for flexible use in laboratories of diversified throughput.

The aim of the present study was to validate new simple‐sequence repeat (SSR) markers and use them to assess genetic variability among 24 isolates of Puccinia triticina collected from wheat (Pt‐wheat) and triticale (Pt‐triticale), and 15 isolates of P. recondita f. sp. secalis (Prs) collected from rye. The Pt and Prs isolates were tested for virulence on a set of 35 Thatcher wheat near‐isogenic lines, eight rye lines with known resistance genes, and 53 triticale cultivars with uncharacterized leaf rust resistance. Molecular genotypes were determined using a newly developed set of 34 SSR microsatellite primer pairs. All SSR markers tested on Pt isolates successfully amplified fragments of appropriate size. When tested on the Prs isolates, 21 out of the 34 Pt SSRs amplified expected fragments. Sixteen of these 21 SSRs were polymorphic, providing for the first time microsatellite markers to study genetic variation in Prs. Based on virulence data, variation among Prs isolates was low, probably due to the small number of rye differential lines available. Much higher variation for virulence was observed within the collection of Pt isolates from wheat and triticale, and two separate groups were established with mixed host origin. Substantial genetic variation was detected among the isolates studied with the SSR markers, assuming two different models of SSR evolution (infinite alleles model and stepwise mutation model). The newly developed set of SSR markers proved their effectiveness in detecting genetic variation and should be useful in further population genetics investigations of the two pathogens.

Triticale (×Triticosecale), the first human-made crop species in a hexaploid form (AABBRR), was obtained by crossing tetraploid wheat (Triticum durum or T. turgidum) with cereal rye (Secale cereale or S. montanum) (Ammar et al., 2004). The first commercially available triticale cultivars for farmers became available in the 1960s.Recently, the global cultivated area of triticale has been estimated at approximately 4 million hectares, with the largest areas occurring in Poland, Belarus, Germany, and France. In Poland, triticale is grown on approximately 1.3 million hectares. In general, triticale combines the high grain quality and yield potential of wheat with the resistance to biotic and abiotic stresses of rye (Ammar et al., 2004; Audenaert et al., 2014).Leaf (brown) rust, which is caused by Puccinia triticina, is an important wheat disease in all geographic regions of the world where wheat is cultivated (Bolton et al., 2008). The development of leaf rust is strongly influenced by environmental conditions, among which temperature and moisture play the most significant role (Kaul & Shaner, 1989). In Poland, under favourable disease conditions, a peak of leaf rust development may start in June and last until leaves senesce at the end of July. For many years, triticale was considered

Badaniami objęto grupę 97 jednozarodnikowych izolatów patogenu, zebranych z różnych odmian pszenicy i pszenżyta na terenie Polski. Analizę wirulencji wykonano w oparciu o zestaw blisko-izogenicznych linii pszenicy, które zawierają pojedyncze, znane geny odporności Lr. Zaobserwowano, że większość izolatów pochodzących z pszenżyta posiadało wirulencję wobec trzech genów Lr. Natomiast wśród izolatów pochodzących z pszenicy przeważały izolaty wirulentne wobec innych trzech genów Lr.

graminis f. sp. tritici and Blumeria graminis f. sp. triticale the causal agents of wheat and triticale powdery mildew Chorobotwórczość Blumeria graminis f. sp. tritici i Blumeria graminis f. sp. triticale sprawców mączniaka prawdziwego zbóż i traw na pszenicy i pszenżycie