رشید پاک نیا - Department of Plant Biotechnology, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.
رضا درویش زاده - Department of Plant Production and Genetics, Faculty of Agriculture and Natural Resources, Urmia University, P. O. Box: ۱۶۵, Urmia, Iran.
شهریار فرج اللهی - Department of Plant Biotechnology, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.
سعید ملک زاده - Department of Plant Biotechnology, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.
حمید حاتمی ملکی - Department of Plant Production and Genetics, Faculty of Agriculture, University of Maragheh, Maragheh, Iran.

Sunflower (Helianthus annuus L.) is one of the four important sources of edible oil in the world. Fungal diseases are considered as major constraints for its seed yield and quality. Basal stem rot resulted by Sclerotinia sclerotiorum (Lib.) de Bary fungus, is known as a serious disease on oily sunflower, worldwide. In this project, genomic region linked with partial resistance to basal stem rot disease was identified using a population of recombinant inbred lines (RILs) created from the hybridization between PAC۲ (♀) and RHA۲۶۶ (♂) lines. Nine phenotypic characters related to disease resistance including PN۴D, PN۸D, PN۱۲D, NCW۱۰۰S, CW۱۰۰S, NCPY, CPY, DP۱۰۰S and DPY were measured under artificial infection in the field conditions. Newly developed genetic linkage map of sunflower was used for detecting and mapping QTLs. The linkage map includes ۲۱۰ SSR and ۱۱ SNP markers distributed in ۱۷ groups. The analysis was carried out using composite interval mapping (CIM) procedure. High coefficient of variation (CV) was detected for those studied characters that reveal high genetic variability for susceptibility to disease in the studied sunflower RIL population. Totally, ۵۶ putative QTLs were identified for the studied nine quantitative characters. The number of QTLs for each character ranged from ۱ to ۹, explaining ۰.۹۱ to ۸۰.۷۵% of phenotypic variation (R۲). Additive effect sign was positive for ۱۷ QTLs, suggesting that the promising allele has been transmitted from male parent (RHA۲۶۶). In this project, major QTLs (LOD≥۲.۵ and R۲≥۱۰%) were identified for all of the studied characters, exceptifor NCW۱۰۰S and CW۱۰۰S characters. The major QTLs are important for running marker-aided selection (MAS) in resistant breeding programs.

Linkage mapping, Oily Sunflower, Partial Resistance, QTL mapping, Sclerotinia sclerotiorum