MINIMAL MICROSATELLITE MARKER PANEL FOR FINGERPRINTING BLUEBERRY CULTIVARS

Blueberries (Vaccinium spp.) are now cultivated in countries far from their origin in North America. In Chile, they were introduced about two decades ago and have become the number one exported berry. Accelerated multiplication of plants by local nurseries was needed to cope with the increasing demand. At the same time, a large number of cultivars were imported to the country, which led to misidentification of several genotypes. The establishment of efficient procedures to determine the genetic identity of existing cultivars became a necessity for the proper protection of Intellectual Property Rights and to trace genotypes during plant propagation. Microsatellite (or simple sequence repeat, SSR) markers for blueberries were recently developed at the USDA, ARS, NCGR-Corvallis Genebank. In our case, SSR markers efficiently differentiated between a minimum of 50 cultivars and enabled the identification of several misnamed cultivars grown in Chile. Our objective was to also determine the most efficient SSR marker set for blueberry identification. Using Cluster Analysis we determined that just two markers (NA-1040 plus CA-421) could distinguish many genotypes provided by the Chilean Phytosanitary Agency (SAG) and the Corvallis Genebank. In cases of uncertainty, several more markers were tested. Our first choice was CA-344, followed by VCC-H9 or CA-794, but the need for additional markers seldom arose.