2018 ASHS Annual Conference

Cultivated southern highbush blueberries are among the high value crops in North Carolina with an estimated annual ~$70 M farm-gate value. Blueberry contains many beneficial components like flavonoids, which can help combat cardiovascular disorders, neurodegenerative diseases, diabetes and cancer thus contributing significantly to the current popularity of the crop. Blueberries are members of the Ericaceae family and include several subgenera or sections. Vaccinium section Cyanococcus is native to North America and all species of this section have contributed to the genetic background of most commercially important cultivars. Traditional breeding efforts to develop superior blueberry cultivars began in 1908 and, as a result, many of today’s cultivars are the product of interspecific hybridization followed by backcrossing. Consequently, modern cultivars are segmental allopolyploids, which share a complex ancestry resulting from the intercrossing of different wild accessions and cultivated varieties. The outbreeding nature of blueberry and the use of inter- and intra-specific hybridization during the past century has generated a lot of speculation about the relationship between the founder species and the modern cultivars. With the advent of next generation sequencing (NGS) technologies, it is currently possible to uncover their interrelation at the whole genome level at a lower cost by sequencing each founder and cultivated species. In this study, using Illumina sequencing, we re-sequenced 28 accessions at 20X genome coverage. The 28 accessions were comprised of 19 different wild and cultivated species from 6 sections in Vaccinium that represent 16 diploids (2n = 2x = 24), 9 tetraploids (2n = 4x = 48), and 3 hexaploids (2n = 6x = 72). The 16 diploids represented 12 different species including: section Cyanococcus [V. caesariense, V. darrowii, V. elliottii, V. fuscatum, V. myrtilloides, V. pallidum and V. tenellum]; section Batodendron [V. arboreum]; section Herpothamnus [V. crassifolium]; section Hemimyrtillus [V. cylindraceum]; section Pyxothamnus [V. ovatum]; and section Polycodium [V. stamineum]. The 9 tetraploids were representative of 6 different species including: section Cyanococcus [V. angustifolium, V. corymbosum, V. formosum, V. myrsinites]; section Hemimyrtillus [V. arctostaphylos] and section Pyxothamnus [V. consanguineum]. The 3 hexaploids were all classified section Cyanococcus [V. virgatum] or Rabbiteye blueberries. The re-sequencing data allowed for the discovery of SNP markers within and between different groups. These SNP markers are easily adaptable to various SNP genotyping platforms that can be used in breeding programs, calculation of minor allele frequency, and defining haplotype blocks.