Development of novel EST‐SSR markers for Rhododendron longipedicellatum (Ericaceae) and cross‐amplification in two congeners

PREMISE OF THE STUDY: To investigate the genetic background and population characteristics of Rhododendron longipedicellatum (Ericaceae), a newly discovered and critically endangered species, expressed sequence tag–simple sequence repeat markers were developed, and transferability was tested in two congeners, R. molle and R. simsii. METHODS AND RESULTS: Based on the transcriptome sequences of R. longipedicellatum, 102 primer sets were designed; 48 primer sets were successfully amplified, with 15 showing polymorphisms in 150 individuals from five extant populations of R. longipedicellatum. The number of alleles per locus ranged from four to 18, and the levels of observed and expected heterozygosity for the 15 loci varied from 0.255 to 0.913 and from 0.306 to 0.851, respectively. All 15 loci were found to amplify in R. molle and R. simsii. CONCLUSIONS: These polymorphic SSR markers can be used in conservation genetic and phylogeographic studies to elucidate the rarity and origin of R. longipedicellatum.