Development of 15 genic-ssr markers in oil-tea tree (Camellia oleifera) based on transcriptome sequencing

Oil-tea tree is one of the most important woody edible oil plants; however, lack of useful molecular markers hinders current genetic research. We performed transcriptome sequencing of developing seeds and characterized microsatellites from transcriptome sequences to identify valuable markers for C. oleifera molecular genetics research. A total of 69,798 unigenes were identified, in which 6,949 putative SSR motifs from 6,042 SSR-containing unique putative transcripts were discovered. Twenty-nine primer pairs corresponding to 29 unigene loci were designed, of which 15 polymorphic genic-SSR markers were developed in 18 varieties and characterized by capillary electrophoresis. The number of alleles per locus (N-a) ranged from 2 to 14, the expected heterozygosity (H-e) ranged from 0.374 to 0.876, and the polymorphism information content (PIC) values ranged from 0.498 to 0.887, respectively. Cross-species amplification was also conducted in 15 varieties of C. japonica. All 15 markers successfully amplified PCR products with expected size in C. japonica and exhibited polymorphisms. The 15 polymorphic genicSSR markers will have potential for applications in genetic diversity evaluation, molecular fingerprinting identification, comparative genome analysis, and genetic mapping in the C. oleifera and C. japonica.