Hybridization of two diploid Vaccinium section Cyanococcus species with diploid Vaccinium arboreum in section Batodendron

Abstract

Several characteristics from sparkleberry (V. arboreum) would be useful if transferred to highbush blueberry cultivars, but to date all direct crosses have failed. The purpose of this research was to see whether crosses of diploid V. darrowii and diploid V. fuscatum (both section Cyanococcus) with diploid V. arboreum (section Batodendron) could be made and to assess the possibility of transferring traits from V. arboreum into cultivated blueberries of section Cyanococcus. Many crosses were successful and easy to make. Crosses were more productive when V. arboreum was the pollen parent, but some hybrids were also obtained with V. arboreum as seed parent. Pollen stainability of F1 (V. darrowii × V. arboreum) hybrids was low, ranging from 0.9 to 23.7%. Numerous meiotic abnormalities were found in the F1 hybrids. These led to a high percentage of incomplete and unstained tetrads and probably to the production of unreduced gametes.