Characterization, validation, and cross-species transferability of EST-SSR markers developed from Lycoris aurea and their application in genetic evaluation of Lycoris species

BackgroundTheLycorisgenus includes many ornamentally and medicinally important species. Polyploidization and hybridization are considered modes of speciation in this genus, implying great genetic diversity. However, the lack of effective molecular markers has limited the genetic analysis of this genus.ResultsIn this study, mining of EST-SSR markers was performed using transcriptome sequences ofL. aurea, and 839 primer pairs for non-redundant EST-SSRs were successfully designed. A subset of 60 pairs was randomly selected for validation, of which 44 pairs could amplify products of the expected size. Cross-species transferability of the 60 primer pairs amongLycorisspecies were assessed inL. radiataHreb,L. sprengeriComes ex Baker,L. chinensisTraub andL. anhuiensis, of which between 38 to 77% of the primers were able to amplify products in theseLycorisspecies. Furthermore, 20 and 10 amplification products were selected for sequencing verification inL. aureaandL. radiatarespectively. All products were validated as expected SSRs. In addition, 15 SSRs, including 10 sequence-verified and 5 unverified SSRs were selected and used to evaluate the genetic diversity of sevenL. radiatalines. Among these, there were three sterile lines, three fertile lines and one line represented by the offspring of one fertile line. Unweighted pair group method with arithmetic mean analysis (UPGMA) demonstrated that the outgroup,L. aureawas separated fromL. radiatalines and that the sevenL. radiatalines were clustered into two groups, consistent with their fertility. Interestingly, even a dendrogram with 34 individuals representing the sevenL. radiatalines was almost consistent with fertility.ConclusionsThis study supplies a pool of potential 839 non-redundant SSR markers for genetic analysis ofLycorisgenus, that present high amplification rate, transferability and efficiency, which will facilitate genetic analysis and breeding program inLycoris.