Feasibility of using dried plant specimens for DNA barcoding. A case study of the Juncaceae

Background: Phylogenetic and barcoding studies usually employ fresh parts of plants as the source of DNA. Successful DNA amplification has been achieved in such investigations for different regions. However, there is need for the utilization of dried samples, due to frequent inaccessibility of fresh precious plants or their parts for genetic analyses or barcoding studies. Difficulties in obtaining amplifiable DNA have appeared as one of the major pitfalls that resulted in slowdown of the use of herbarium specimens for DNA analyses. Methods: . Recent study highlights the crucial issues that are being faced by comparison of herbarium and fresh plants for barcoding purposes. We analyzed the performance of samples from herbarium specimens of different age and fresh plants in PCR reaction and sequencing of seven regions (cpDNA: rbc L, rpo C1, trn L-F intergenic spacer, trn L intron, psb A- trn H , mtDNA: atp 1 and nrDNA: ITS1-5.8S-ITS2) with a combination of twenty-eight primers. Conclusions: . We show that herbarium specimens may be successfully applied both for phylogenetic as well as for barcoding purposes. In comparison with fresh samples, working with dried herbarium specimens is more complicated, but may lead to amplification and sequencing success in almost all cases when appropriate internal primers are designed or optimization methods are used. Both attempts are useful for this aim: using the set of universal primers recommended by CBOL and design specific primers for a particular group of interest. We found limited detrimental effect of specimen age and length of the amplicon on the amplification success in most of the tested regions in the Juncaceae.