Abstract: To develop co-dominant DNA markers in pansy（Viola × wittrockiana），167 576 unigenes from pansy transcriptomic database were screened by MISA software. A total of 23 791 simple sequence repeat（SSR）loci were detected in the unigenes with the frequency of 14.20%，and the average distribution distance of SSR was 6.75 kb. The predominant type of SSR was trinucleotide repetition amounting for 28.31% of total SSRs，followed by dinucleotide repetition accounting for 12.86%. AG/CT and GAA/TTC are the dominant elements in dinucleotide and trinucleotide repetitions，accounting for 4.01% and 1.85% of the total SSRs，respectively. Primer 3 was employed to design SSR primers and a total of 6 863 pairs of SSR primers were obtained. Thirty pairs of primers were randomly selected for PCR in pansies，in which 18 pairs of primers amplified clear and repeatable bands and showed polymorphism in 42 pansy germplasm accessions. Based on the amplified polymorphic SSR data，the dendrogram results were in accordance with the genetic backgrounds of 42 accessions. Therefore，a large amount of SSR markers can be developed from transcriptome sequencing and employed in genetic linkage map construction and functional gene mapping in pansy.

Key words: pansy, EST-SSR, hierarchical clustering, cucurbits crop, in vitro gynogenesis, haploid, double haploid