Cold hardiness of southern-adapted blueberry (Vaccinium × hybrid) genotypes and the potential for their use in northern-adapted blueberry breeding |
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| Authors: | M K Ehlenfeldt L J Rowland E L Ogden and B T Vinyard |
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| Institution: | United States Department of Agriculture, Agricultural Research Service, Philip E Marucci Center for Blueberry and Cranberry Research and Extension, 125A Lake Oswego Road, Chatsworth, New Jersey 08019,USA, E-mail:;;United States Department of Agriculture, Agricultural Research Service, Henry A. Wallace Beltsville Agricultural Research Center, Genetic Improvement of Fruits and Vegetables Laboratory, Bldg. 010A, BARC-West, Beltsville, Maryland 20705,USA;;United States Department of Agriculture, Agricultural Research Service, Henry A. Wallace Beltsville Agricultural Research Center, Biometrical Consulting Service, Bldg. 005, BARC-West, Beltsville, Maryland 20705,USA |
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| Abstract: | Twelve southern-adapted blueberry genotypes, both southern highbush ( Vaccinium corymbosum L. introgressed with 2x V. darrowi Camp) and rabbiteye ( V. ashei Reade), were evaluated for bud development using a morphological scale and for mid-winter cold hardiness using a shoot freezing assay. The winter of 2006–2007 was particularly warm producing higher bud development scores for several of the genotypes and an apparent decrease of cold hardiness. Significant differences in LT50 values (treatments causing 50% bud mortality) were observed among the genotypes in both years, with a significant clone × year interaction. The greatest range in LT50 values occurred in 2007, when values ranged from ?11.9°C for 'Millennia' to ?25.5°C for 'Reveille', two southern highbush cultivars. Results suggest that germplasm selected in North Carolina might typically have sufficient cold hardiness to be used without concern as parental material in the development of blueberry germplasm with northern adaptation. Other more southern germplasm was generally less hardy and, if utilized as parental material, the resulting progeny would require greater scrutiny with regard to cold hardiness. |
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| Keywords: | southern highbush northern highbush rabbiteye Vaccinium corymbosum Vaccinium ashei deacclimation freezing tolerance |
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