2019 ASHS Annual Conference

During the blueberry breeding history, interspecific hybridizations have been widely used as source of novel agronomic traits. A successful example was the development of Southern Highbush Blueberries (SHB) through the hybridization of a US northern adapted highbush species (Vaccinium corymbosum) with a native Floridian species (Vaccinium darrowii), which resulted in reduction of chilling hours requirement, resistance to diseases, as well as improvement in fruit quality. Vaccinium elliottii possesses multiple traits that can benefit the blueberry production in the southern US. Besides the high sugar content and characteristic aroma, this species also presents a short bloom to ripe period, which could positively affect the earliness on new cultivars. Moreover, since the species naturally occurs in the Southeast of US, its introgression into SHB background may also improve adaptation to well drained sandy soils, which could lower the cost of soil amendments for growers. Therefore, the main objective of this study was to identify V. elliottii individuals and crossing combinations with SHB showing superior phenotypic performances, with the future ultimate goal of introgressing the favorable traits from V. elliottii into SHB cultivars. To this end, two F2 hybrid families were evaluated for four agronomical traits (plant vigor, plant height, disease resistance, and plant survival) and for five fruit quality traits (berry size, firmness, soluble solids content, pH, and titratable acid). Results from fruit quality showed an increase on berry size on F2 hybrids when compared with V. elliottii, while a decrease in berry size compared to SHB. The highest levels of soluble solids were found in V. elliottii compared with SHB and F2 hybrids. F2 hybrids had a significantly lower acidity (titratable acids) compared with V. elliottii, but significantly higher acidity compared to SHB. No significant differences in firmness was found between hybrids and SHB. Results show that in two rounds of crossing the values for economically important traits were compatible between the hybrids and SHB, which suggests that it may be suitable to introgress important traits from V. elliottii into SHB without losing important quality traits from SHB