Production of Intersectional Hybrids between Colchicine-induced Tetraploid Shashanbo (Vaccinium bracteatum) and Highbush Blueberry 'Spartan'

With crosses between colchicine-induced tetraploid shashanbo (Vaccinium bracteatum section Bracteata) and tetraploid highbush blueberry 'Spartan' (Vaccinium corymbosum section Cyanococcus), intersectional hybrids were produced. The hybridity of these plants was confirmed based on DNA markers and morphological characteristics. The morphological characteristics, blooming date, and ripening period of the hybrids were intermediate between those of the parents. Ploidy analyses by flow cytometry and chromosome counting revealed that these hybrids were tetraploid. Four hybrids set fruit in the field and these two hybrids showed high pollen stainability. It was noteworthy that fruit of two hybrids had high soluble solids concentration compared with 'Spartan' and the fruit pulp of the hybrids was tinged with red as shashanbo. These hybrids could be useful in breeding new cultivars with high sugar content, abundant phytochemicals, extensive environmental adaptability as well as late flowering and fruit maturity.