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ARS Home » Southeast Area » Poplarville, Mississippi » Southern Horticultural Research » Research » Publications at this Location » Publication #334374

Research Project: Small Fruit and Ornamental Genetic Research for the Mid-South

Location: Southern Horticultural Research

Title: Variation in nuclear DNA content and chromosome numbers in blueberry

Author
item Sakhanokho, Hamidou
item Rinehart, Timothy - Tim
item Stringer, Stephen
item Islam-faridi, Nurul - Us Forest Service (FS)
item Pounders, Cecil - Retired Ars Employee

Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/14/2018
Publication Date: 1/20/2018
Citation: Sakhanokho, H.F., Rinehart, T.A., Stringer, S.J., Islam-Faridi, M.N., and C.T. Pounders. 2018. Variation in nuclear DNA content and chromosome numbers in blueberry. Sci. Hort. 233:108-113

Interpretive Summary: Commercial blueberry production in the U.S. relies on cultivars derived from combinations of different blueberry species. Interspecific hybridization continues to be a vital strategy for blueberry breeding, especially in regards to improving abiotic and biotic tolerance to expand the range of production. Blueberry species have many different genome sizes, presumably due to differing ploidy levels and/or DNA content. In some species, such as Vaccinium corymbosum (highbush blueberries) and V. pallidum (Hillside blueberry), there are also different ploidy series available for breeding, further complicating the observed DNA content in elite selections. Here we determined DNA content in 74 blueberry taxa including 10 original species and 63 hybrid cultivars and selections from a breeding program in the southeastern U.S. The results obtained here can be valuable for taxonomic classification studies and breeding and selection of improved blueberry varieties.

Technical Abstract: Commercial blueberry production in the U.S. relies on cultivars derived from combinations of different blueberry species. Interspecific hybridization continues to be a vital strategy for blueberry breeding, especially in regards to improving abiotic and biotic stress tolerance to expand the range of production. Blueberry species have many different genome sizes, presumably due to differing ploidy levels and/or DNA content. In some species, such as Vaccinium corymbosum L. and V. pallidum Aiton, there are also different ploidy series available for breeding, further complicating the observed DNA content in elite selections. In this study we determined DNA content in 77 blueberry taxa including 11 species and 64 hybrid cultivars. Among these taxa are 11 diploid, 49 tetraploid, one pentaploid, and 16 hexaploid plants representing southern highbush, northern highbush, low bush, rabitteye, and half high blueberries. DNA content was measured for three separate tissue samples from at least three individual plants per taxa for accuracy. Absolute genome sizes varied significantly (P'='0.05) among ploidy levels, with 2C-value means of 1.09'pg for diploid, 2.10'pg for tetraploid, and 3.60'pg for hexaploid taxa. Holoploid genome size (2C DNA) was significantly correlated with ploidy or presumed chromosome number (2n) (r'='0.96, P'='0.0001) but only weakly correlated with monoploid genome size (1Cx-DNA) (r'='0.43, P'='0.0001).