Safflower ( Carthamus tinctorius L. ) belongs to Asteraceae family. Safflower is known as one of the major oilseed crops in the world with commercial uses. Iran have been considered as the center of origins of this plant, so the assessment of genetic diversity is a prerequistic for evoloutionary studing in this plant. Precise genetic relationships among cultivars using molecular DNA markers is necessary to make better breeding programs. The objectives of this study were: (1) to isolate and identify microsatellites from the safflower genome; and (2) to detect the polymorphisms among safflower genotypes using microsatellites. In this study, Hamilton et al. (1999) procedure was used to develop new safflower SSR primers. Genomic DNA extracted from Koose 1 cultivar. The extracted DNA was digested with Nhe I, Rsa I, Alu I, Hae III and Xmn I. Enrichment was done by hybridizing a microsatellite containting fragments with biotin-labeled probes such as (AG) 15 or (ATG) 10 . These probes were captured using magnetic beads coated with streptavidin. Biotinylated oligoucleotides had extremely high affinity with streptavidin. The purified fragments were ligated to pBluescript plasmid vector and transferred in to E.coli (MC1061). Colonies containing microsatellite motifs were selected using Colony PCR procedure. Thirty-five colonies were screened out of which 24 (68.5%) had SSR motifs. Among these colonies, twenty were found to be suitable for primer designing. After optimization of primers, they were used to amplify the genomic DNA extracted from 22 genotypes. These genotypes included 13 cultivated safflower and nine wild accessions. Twenty-one primers were designed in which only 16 primer pairs produced the expected amplification product in safflower cultivars. Of 21 SSR loci, 15 showed polymorphic patterns. The scored bands were analysed using Powermarker V3.25 and Mega 4 softwares. The average number of polymorphic alleles and PIC value were 2.85 and 0.3665, respectively. Results showed that cultivated and wild genotypes were clustered in two major groups. The dendrogram separated Iranian cultivars from foreign types. It seems that some of the Iranian and foreign genotypes were probably mixed during their evolutionary process. Key words: safflower, enrichment, microsatellite isolation, genetic diversity
