ISHS Acta Horticulturae 810: IX International Vaccinium Symposium
DETECTION OF COLCHICINE INDUCED TETRAPLOIDS OF VACCINIUM ARBOREUM WITH FLOW CYTOMETRY |
| Authors: | R.A. Haring, P.M. Lyrene |
| Keywords: | Ploidy analysis (PA), relative fluorescence intensities (RFI), mixoploid plants |
| Abstract:
Vaccinium arboreum Marshall (2n=2x=24) is an arborous blueberry native to the southeastern United States. It is considered a potential gene pool for diversifying V. corymbosum L. (2n=4x=48). In order to cross V. arboreum with tetraploid highbush cultivars, its diploid genome must be doubled to allow for an intersectional homoploid cross. The use of a modified protocol for Partec’s flow cytometric ploidy analysis (PA) disclosed three relative fluorescence intensities (RFI) associated with ploidy levels for meristematic tissue from V. arboretum. The mean RFI for the diploid genome was 59.7, while the mean RFI for potential mixoploids (having two fluorescent peaks) were 72.8 and 142.8, respectively, and the mean RFI for tetraploids was 127.0. A colchicine experiment was set up in 2006, wherein dried V. arboreum seeds were imbibed in 0.2% or 0.5% colchicine for 96 h, followed by 0, 1, 2, or 3 post-plant treatments of 0.2% colchicine for 5 h A 24 hour seedling-dip treatment at 0.2% colchicine was also tested. Preliminary flow cytometric analysis of 366 V. arboreum meristem tissue samples indicated 231 diploids, 123 mixoploids, and 12 tetraploids detected. A Chi-square Test of Independence did not indicate any superior treatment types for inducing genome doubling; X2 = 4.28 < 7.82 at p = 0.05. Flow cytometric analysis was able to quickly differentiate and quantify ploidy levels of numerous samples, although verification of designated mixoploids and tetraploids is required. The development of a modified Partec ploidy analysis protocol for V. arboreum continues, and the significance of the RFI histogram signatures continues to be studied. | |
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