Characterization of backcross blueberry populations created to introgress Vaccinium arboreum traits into southern highbush blueberry
Southern highbush blueberry (SHB) cultivars resulted from crosses among wild Vaccinium species in section Cyanococcus native to the southeastern US and Vaccinium corymbosum (VC) selections. One of the most recent wild species to be used in crosses with SHB germplasm is V. arboreum (VA). Unlike the previous crosses, VA belongs to the section Batodendron. VA has several adaptive characteristics of interest for blueberry production, such as single trunk architecture, open racemes, deeper root systems, and higher fruit soluble solids. Two half-sib first generation pseudo-backcrosses (BC) were selected for study and twenty-five vegetative, reproductive, and postharvest parameters were measured. Phenotypic data were collected during 2012 and 2013 on two- and three-year-old BC plants, respectively. Results indicated that vegetative, reproductive, and postharvest traits have been successfully introgressed from VA into SHB. For example, the low adventitious rooting from softwood cuttings of VA was observed, with one of the BC populations segregating from zero to 100 percent rooting. The longer pedicel and peduncle from VA (average of 8.5 mm and 61.6 mm, respectively) in comparison with SHB (average of 5.1 and 10.3 mm, respectively) were also observed in the BC individuals where there was a range from 2.8 to 8.3 mm for pedicel length and from 3.9 to 21.9 mm for peduncle length. Fruit firmness was improved by introgression from VA, with both BC population means significantly higher (P‹0.05) than SHB. However, stringent selection must be applied in early generations to retain desirable traits and eliminate negative traits.
Rodríguez-Armenta, H.P., Olmstead, J.W. and Lyrene, P.M. (2017). Characterization of backcross blueberry populations created to introgress Vaccinium arboreum traits into southern highbush blueberry. Acta Hortic. 1180, 435-444
sparkleberry, phenotype, blueberry, interspecific cross, rooting