Submitted to: Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/12/2022
Publication Date: 11/18/2022
Citation: Ehlenfeldt, M.K., Rowland, L.J., Ogden, E.L., Luteyn, J.L. 2022. Asymmetric reciprocal crossing behavior of an andean blueberry (V. Meridionale) × lingonberry (V. Vitis-idaea) Hybrid. Plants. 11(22):3152. https://doi.org/10.3390/plants11223152.
Interpretive Summary: The Andean blueberry (V. meridionale) is a species that has many characteristics of potential value to the commercial highbush blueberry, including vigor, upright structure, concentrated flowering, and high productivity. In evaluating the use of Andean blueberry for breeding, we examined the crossing behavior of a hybrid between Andean blueberry and lingonberry. When this hybrid was used as a female with highbush blueberry males, virtually all offspring had six sets of chromosomes and hence are termed hexaploid; however, when it was used as a male with highbush blueberry, only tetraploid hybrids with four sets of chromosomes were produced. Such asymmetric crossing behavior is unprecedented in any commercial crop species. The ability to produce both 6x and 4x offspring from the same parents allows the potential breeding of Andean blueberry germplasm into both the tetraploid highbush blueberry and hexaploid rabbiteye blueberry. This discovery will be of interest to blueberry researchers and geneticists, and to blueberry breeders.
Technical Abstract: The fertility and crossing behavior of a 4x hybrid between Andean blueberry (V. meridionale) and lingonberry (V. vitis-idaea) was evaluated through a series of crosses. When the hybrid was used as a female with V. corymbosum males, virtually all offspring were hexaploid, most likely arising from 2n=4x=48 female gametes, and 1n=2x=24 male gametes. However, when the hybrid was used as a male, tetraploid hybrids were produced, resulting from 1n=2x=24 gametes from each parent. To further examine this crossing behavior, the 4x interspecific hybrid was used as a female with 6x V. virgatum (rabbiteye blueberry). Analogous to the previous crosses, 7x hybrids were produced from the joining of 2n=4x=48 female gametes with 1n=3x=36 male gametes. Limited tests suggest the reciprocal cross produces 5x progeny. Such asymmetric crossing behavior is unprecedented. The ability to produce both 6x and 4x offspring from the crosses with V. corymbosum allows the potential of bridging V. meridionale germplasm to both the tetraploid (V. corymbosum) and hexaploid (V. virgatum) commercial crop levels.