Fertile Intersectional Hybrids of 4x Andean Blueberry (Vaccinium meridionale) and 2x Lingonberry (V. vitis-idaea)

Abstract

Vaccinium meridionale (section Pyxothamnus), a tetraploid species native to higher-altitude locations in Jamaica, Colombia, and Venezuela, is of interest to Vaccinium breeders for its profuse, concentrated flowering, vigor, and monopodial plant structure, all of which may be useful in breeding for mechanical harvest in blueberry. In this study, tetraploid V. meridionale was successfully hybridized as both female and male with 2x Vaccinium vitis-idaea (section Vitis-idaea, lingonberry). The resultant F1 hybrids with lingonberry were both 3x and 4x, respectively. These hybrids were intermediate in morphology and notably vigorous. Most appear to be evergreen, with small, red-colored fruit. The 4x F1 hybrids displayed good fertility as females in backcrosses to both lingonberry and V. meridionale. Pollen production and quality were evaluated as an indicator of male fertility. Most clones had good pollen shed and high frequencies of well-formed tetrads. The overall fertility suggests that these hybrids, despite being derived from intersectional crosses, might be conventionally used for breeding without substantial difficulty.