Blueberries and cranberries

Abstract

Most blueberry breeding activity is focused on northern highbush, southern highbush and rabbiteye types. The major objectives of blueberry breeders center on high plant vigor, improved disease resistance, flavor, longer storing fruit and expanded harvest dates. Cranberry breeders have concentrated on early maturing fruit, uniform large size, intense color, keeping quality, high productivity, disease resistance and plant vigor. Considerable variability exists in blueberry and cranberry for most of the horticulturally important traits, and while only a limited number of genetic studies have been performed, most inheritance patterns fit quantitative models. Several genes have been identified through molecular, genetic and genomic approaches that are associated with cold hardiness. Wide hybridization is commonly employed in blueberry breeding and southern highbush types were derived primarily by incorporating genes from the diploid species Vaccinium darrowii into the highbush background via unreduced gametes. A wide array of molecular markers has been used in blueberry for fingerprinting and linkage mapping, and a major QTL regulating the chilling requirement in diploids has been identified. Transgenic blueberries have been produced with herbicide resistance and the Bt gene (Bacillus thuringiensis) has been incorporated into cranberry. A large EST library of highbush blueberry has been produced.