Genetic Diversity and Population Structure In Blueberry Evaluated with Genic and Genomic SSR Markers

Blueberry (Vaccinium spp. section Cyanococcus) is an economically important small fruit crop in the United States and other parts of world. Numerous nutritional and health benefits have been recognized with blueberry consumption and are currently being investigated. Most commercialized blueberry varieties are the product of complex hybridizations and selection schemes between and within several distinct species of Vaccinium. Considerable variation in regards to compounds associated with health is present within these species of Vaccinium and provides unique opportunities to breed varieties that satisfy specific phytochemical profiles. A survey to estimate phytochemical variability within blueberry germplasm in North Carolina is currently underway. This study is a companion to that survey to estimate the genetic diversity and population structure of the same material. To date, genetic diversity studies in blueberry have been limited to selected populations and to our knowledge few comparisons have been made utilizing different classes of DNA markers. The deduced phylogenetic relationships from these previous studies have not always been in agreement with available pedigree information; possibly due to the limited number of available markers or due to bias introduced by the types of markers utilized. We are currently developing novel genomic microsatellite markers from a draft blueberry genomic sequence. The frequency, type and distribution of SSRs in the blueberry genome are presented. Genetic diversity in North Carolina germplasm and the USDA blueberry core collection are evaluated using SSR markers identified from genomic and genic regions and the estimates are evaluated against known pedigree information.