RESUMO
Background: downy mildew caused by Plasmopara halstedii is a devastating disease in sunflower worldwide. Several dominant resistance genes designated as Pl have been identified and linked molecular markers have been demonstrated. However, no information on theresistance genes is available forIranian lines
Objectives: the presence of three map-based molecular markers previously proved to be linked to different resistance genes were evaluated in sunflower inbred lines
Materials and Methods: using PCR-based and CAPS molecular markers, 26 sunflower inbred lines with different responses to P. halstedii race 100 were used to detect the presence of three resistance loci including Pl[1], Pl[6]and Pl[13] within the lines
Results: molecular marker linked to Pl[13] was present in some of the sunflower lines but was not correlated with the phenotypic reaction of the lines to race 100. Despite the use of three markers linked to Pl[6], PCR failed to amplify any corresponding product. This data may suggest that none of the genotypes possessed Pl[6] locus. Pl[1]-linked cleaved amplified polymorphic sequences [CAPS] were present in several resistance lines and effectively differentiated susceptible and resistant sunflower lines
Conclusions: applicability of molecular markers in breeding programs revisited in disease management