Validation of Microsatellite Markers of Pl Resistance Genes to Downy Mildew of Sunflower

Abstract

Abstract Simple sequence repeats (SSR) polymorphism of 34 microsatellite loci (LG1, 8 and 13) was studied in lines carrying the downy mildew resistance genes Pl and lines with no Pl. The microsatellite loci ORS328 and ORS781 were selected as markers for genes Pl6 and Pl8 in lines HA 335 and QHP-1, respectively. Markers were identified for gene PlARG in RHA 419 and some accessions of H. argophyllus. The SSR markers ORS509, ORS605, ORS610, ORS1182 and ORS1039 were proven to reliably identify the parental line carrying PlARG gene, control and select the heterozygous F1 hybrids and identify homozygous genotypes in F2 generations. Obtained results indicate the necessity of validation of the markers in various germplasm pools and breeding collections. The SSR markers that are tightly linked to Pl6, Pl8, PlARG would be useful in the sunflower breeding. PlARG homozygous F2 segregants, developed and identified with marker assisted selection in this study, are recommended for further breeding as a new source of genetically determined resistance to downy mildew.