The North Carolina State University Blueberry Breeding Program - Toward V X Covilleanum?

In addition to standard tetraploid highbush blueberry (V. corymbosum L.) and hexaploid rabbiteye blueberry (V. ashei reade) cultivar development, the major thrust of the North Carolina breeding program involves interspecific hybridization and introgression involving 13 species in Vaccinium section Cyanococcus and one species each in sections Batodendron, Polycodium and Pyxothamnus. These latter efforts are directed primarily toward development of tetraploid southern highbush genotypes; and in addition to V. darrowi, involve V. amoenum, V. angustifolium, V. arboreum, V. ashei, V. elliottii, V. myrsinites, V. myrtilloides, V. ovatum, V. pallidum, V. simulatum, V. stamineum, and V. tenellum. Pentaploid hybrids involving V. corymbosum x V. ashei, V, corymbosum x (V. constablaei x V. ashei), V. angustifolilum x V. ashei, V. pallidum x V. ashei and V. pallidum x V. amoenum are also being backcrossed to hexaploid genotypes. In addition, V. angustifolium and V. elliottii are specifically being used to incorporate resistance to stem blight (Botryosphaeria dothidea), while V. amoenum, V. ashei and V. elliottii and serving as sources of natural resistance to the sharpnosed leafhopper (Scaphytopius magdalensis blueberry stunt MLO vector). Elite genotypes at the tetraploid, pentaploid and hexaploid chromosome levels are currently being evaluated as potential new cultivars for fruit production.