A study was conducted to determine the presence of resveratrol, pterostilbene, and piceatannol in Vaccinium berries. Samples representing selections and cultivars of 10 species from Mississippi, North Carolina, Oregon, and Canada were analyzed by gas chromatography/mass spectrometry. Resveratrol was found in Vaccinium angustifolium (lowbush blueberry), Vaccinium arboretum (sparkleberry), Vaccinium ashei (rabbiteye blueberry), Vaccinium corymbosum (highbush blueberry), Vaccinium elliottii (Elliott's blueberry), Vaccinium macrocarpon (cranberry), Vaccinium myrtillus (bilberry), Vaccinium stamineum (deerberry), Vaccinium vitis-ideae var. vitis-ideae (lingonberry), and Vaccinium vitis-ideae var. minor (partridgeberry) at levels between 7 and 5884 ng/g dry sample. Lingonberry was found to have the highest content, 5884 ng/g dry sample, comparable to that found in grapes, 6471 ng/g dry sample. Pterostilbene was found in two cultivars of V. ashei and in V. stamineum at levels of 99-520 ng/g dry sample. Piceatannol was found in V. corymbosum and V. stamineum at levels of 138-422 ng/g dry sample. These naturally occurring stilbenes, known to be strong antioxidants and to have cancer chemopreventive activities, will add to the purported health benefits derived from the consumption of these small fruits.

Anthocyanins and phenolic acids are major secondary metabolites in blueberry with important implications for human health maintenance. An improved protocol was developed for the accurate, efficient, and rapid comparative screening for large blueberry sample sets. Triplicates of six commercial cultivars and four breeding selections were analyzed using the new method. The compound recoveries ranged from 94.2 to 97.5 ± 5.3% when samples were spiked with commercial standards prior to extraction. Eighteen anthocyanins and 4 phenolic acids were quantified in frozen and freeze-dried fruits. Large variations for individual and total anthocyanins, ranging from 201.4 to 402.8 mg/100 g, were assayed in frozen fruits. The total phenolic acid content ranged from 23.6 to 61.7 mg/100 g in frozen fruits. Across all genotypes, freeze-drying resulted in minor reductions in anthocyanin concentration (3.9%) compared to anthocyanins in frozen fruits. However, phenolic acids increased by an average of 1.9-fold (±0.3) in the freeze-dried fruit. Different genotypes frequently had comparable overall levels of total anthocyanins and phenolic acids, but differed dramatically in individual profiles of compounds. Three of the genotypes contained markedly higher concentrations of delphinidin 3-O-glucoside, cyanidin 3-O-glucoside, and malvidin 3-O-glucoside, which have previously been implicated as bioactive principles in this fruit. The implications of these findings for human health benefits are discussed.

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The use of interspecific hybridization in blueberry (Vaccinium L. section Cyanococcus Gray) breeding has resulted in the incorporation of novel traits from wild germplasm and the expansion of the geographic limits of highbush blueberry (V. ×corymbosum L.) production. The objectives of this study were: 1) to estimate the impact of wide hybridization on inbreeding, heterozygosity, and coancestry of the cultivated tetraploid highbush blueberry; 2) to establish the usefulness of microsatellite markers in assessing genetic relationships among southern highbush blueberry [SHB (V. ×corymbosum)] cultivars; and 3) to report on the expected genetic contribution of wild Vaccinium clones to SHB cultivars. Pedigrees of 107 highbush blueberry cultivars were used to calculate tetrasomic inbreeding coefficients (F), pedigree-based genetic distances, and expected genetic contributions of wild clones. Genotyping data from 21 single-locus microsatellite markers screened across 68 genotypes were used to calculate heterozygosity and proportion of shared alleles distances (Dsa). The results indicated that the effects of wide hybridization on genetic diversity of cultivated blueberry were lower than previously thought. First, SHB cultivars exhibited similar levels of molecular relatedness as historical northern highbush blueberry [NHB (V. ×corymbosum)] cultivars (median Dsa between pairs of cultivars equals 0.19 in both cultivar groups), despite the broader genetic base and larger pedigree distances in the former cultivar group. Second, levels of heterozygosity in modern NHB cultivars were not statistically different from those of SHB (χ2 = 4.0; df = 3; P > 0.05), despite the considerably higher levels of inbreeding in the former cultivar group (median F equal to 0.0035 and 0.0013, respectively). Furthermore, pedigree-based genetic distances were significantly correlated with Dsa (r = 0.57, P ≤ 0.0001), indicating that microsatellite markers are reliable tools in most cases to assess the genetic relationships among SHB cultivars. Finally, seven Vaccinium species constitute the current genetic base of cultivated SHB. In this article, we report on the expected genetic contributions of V. angustifolium Ait., V. constablaei Gray, V. corymbosum, V. darrowii Camp, V. elliottii Chapman, V. tenellum Ait., and V. virgatum Ait. (syn. V. ashei Reade) clones to 38 SHB cultivars.

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