Development and cross-species transferability of unigene-derived microsatellite markers in an edible oil woody plant, Camellia oleifera (Theaceae)

Camellia oleifera is an important edible oil woody plant in China. Lack of useful molecular markers hinders current genetic research on this tree species. Transcriptome sequencing of developing C. oleifera seeds generated 69,798 unigenes. A total of 6949 putative microsatellites were discovered among 6042 SSR-containing unigenes. Then, 150 simple sequence repeats (SSRs) were evaluated in 20 varieties of C. oleifera. Of these, 52 SSRs revealed polymorphism, with the number of alleles per locus ranging from 2 to 15 and expected heterozygosity values from 0.269 to 0.888. The polymorphic information content varied from 0.32 to 0.897. Cross-species transferability rates in Camellia chekangoleosa and Camellia japonica were 90.4 and 78.8%, respectively. The 52 polymorphic unigene-derived SSR markers serve to enrich existing microsatellite marker resources for C. oleifera and offer potential for applications in genetic diversity evaluation, molecular fingerprinting, and genetic mapping in C. oleifera, C. chekangoleosa, and C. japonica.