Efficient Fingerprinting of the Tetraploid Salix psammophila Using SSR Markers

Salix psammonphila C. Wang et Ch. Y. Yang is an important desert shrub that is mainly distributed in northwest China, including the Mu Us sandland and Kubuqi desert. It plays a crucial role in vegetation rehabilitation and as a forestation plant. The traditional identification of its accessions based on phenotypic traits is usually unreliable. SSR (Simple Sequence Repeat) has the advantages of repeatability and codominant inheritance, and most species have had specific SSR primers developed for them already. Currently, there is no simple and rapid method used for identifying the tetraploid Salix psammophila with SSR markers. In this study, we construct fingerprints among 261 accessions of S. psammophila by screening of marker combinations. We identified a nine-marker combination which could completely distinguish each of the 261 accessions to their unique fingerprinting profiles. For this marker combination (G+I+J+N+O+Q+S+T+U), identification rate of combined markers (MC2) and total Polymorphism Information Content (PIC) were the highest, at 100% and 6.05, respectively. We used fingerprinting profiles with the nine-marker combination to produce two-dimensional barcodes, which could be screened rapidly and conveniently using a barcode scanned by a computer. The results of this study can provide an efficient genetic toolkit for identification, traceability management and protection of intellectual property rights of particular accessions of tetraploid S. psammophila.