Highly fertile intersectional blueberry hybrids of Vaccinium padifolium Section Hemimyrtillus and V. corymbosum Section Cyanococcus

Authors: Ehlenfeldt, Mark; Polashock, James

Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/4/2013
Publication Date: 1/2/2014
Publication URL: https://handle.nal.usda.gov/10113/61470
Citation: Ehlenfeldt, M.K., Polashock, J.J. 2014. Highly fertile intersectional blueberry hybrids of Vaccinium padifolium Section Hemimyrtillus and V. corymbosum Section Cyanococcus. Journal of the American Society for Horticultural Science. 139:30-38.

Interpretive Summary: Lowbush, highbush, and rabbiteye blueberries in commercial production in North America are limited to three blueberry species. In order to increase genetic diversity in northern higbush and lowbush blueberry, Vaccinium padifolium, a species native to the Portuguese islands of Madeira, was introduced into the breeding program. The species is distantly related to commercial blueberries, but has features of notable value to conventional blueberry development, among these: upright structure, strong growth, abundant flowering and fruiting, good self-fertility, a fruit-cluster structure suited to mechanical harvesting, and repeat flowering. We hybridized V. padifolium with commercial blueberry and produced two highly fertile hybrids. These hybrids were intermediate in appearance to their parents, and their hybridity was confirmed through DNA testing. These hybrids were used in further crosses to a variety of conventional blueberries to develop new breeding lines for use in developing improved blueberry cultivars. These hybrids will be of value to blueberry breeders and to the commercial blueberry production industry.

Technical Abstract: The primary gene pool of Vaccinium species used by blueberry breeders has traditionally been the North American Vaccinium species of Section Cyanococcus. Blueberries in commercial production represent three primary Vaccinium species and two ploidy levels. Significant use has been made of the secondary gene pool of Vaccinium, especially in the development of southern highbush cultivars. Section Hemimyrtillus species are distantly related and are best considered part of the tertiary gene pool of Vaccinium. V. padifolium Smith, native to the Portuguese islands of Madeira, has features of notable value to conventional blueberry development, among these: upright structure, strong growth, abundant flowering and fruiting, good self-fertility, inflorescence structure suited to mechanical harvesting, and indeterminate/repeat flowering. We used V. padifolium as a female in crosses with V. corymbosum, and generated two highly fertile hybrids. These hybrids were intermediate in morphology, and their hybridity was additionally confirmed through DNA testing. These hybrids were used in further crosses to a variety of section Cyanococcus selections and have generated numerous secondary hybrids. We have also determined by flow cytometry, the ploidies of the hybrids and several previously unevaluated section Hemimyrtillus species.