Resumo

TORRES PACHECO, Irineo et al. Genetic markers of resistance to rust stem(Puccinia graminis Persoon f. sp. avenae) in oat (Avena sativa L.). Agric. Téc. Méx [online]. 2007, vol.33, n.3, pp.221-230. ISSN 0568-2517.

Stem rust (Puccinia graminis Persoon f. sp. avenae) reduces oat productivity in Mexico. Present day oat cultivars are susceptible to this disease. The objective of this study was to search and identify molecular markers for genes linked to stem rust resistance in four oat cultivars. During the spring-summer season of 2004, cultivars Chihuahua, Obsidiana, Cevamex and Karma were sown under rainfed conditions in seven locations and evaluated for stem rust reaction and in 2005 were inoculated under greenhouse conditions in order to assess the reaction of the cultivars to eight different isolates of oat stem rust collected from different locations in Mexico. Thirty primers with regions NBS-LRR in the oat genome and twelve additional primers selected on the basis of its background as being linked to stem rust resistance genes in gramineous crops were used. The identification of the markers was made following the concept of analogous resistance genes and the comparative map of the species. Evaluations at field and greenhouse conditions showed that cultivar Chihuahua was susceptible, Obsidiana and Cevamex were moderately resistant and Karma was resistant. Concurrently, Karma showed the highest number of polymorphic markers (17) linked to stem rust resistance genes. Primers: PIC 11-K2/PIC11-WEL, Kinase2 D-E/ KQCFA 3-4, PLOOP1-4/WMA1-4, Kinase2 D-E/WMA1-4, NBS B, F2/R2 y Hv3Lrk, might be markers associated to stem rust resistance in oats.

Palavras-chave : Oats; genetic markers; resistance; stem rust.