Cold hardiness of southern-adapted blueberry (Vaccinium x hybrid) genotypes and the potential for their use in northern-adapted blueberry breeding

• Published in: Plant breeding Vol. 128; no. 4; pp. 393 - 396
• Main Authors: Ehlenfeldt, M.K, Rowland, L.J, Ogden, E.L, Vinyard, B.T
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.08.2009; Blackwell Publishing Ltd; Blackwell
• Subjects: Adaptation to environment and cultivation conditions; Agronomy. Soil science and plant productions; Biological and medical sciences; deacclimation; freezing tolerance; Fundamental and applied biological sciences. Psychology; Generalities. Genetics. Plant material; Genetic resources, diversity; Genetics and breeding of economic plants; northern highbush; Plant material; rabbiteye; southern highbush; Vaccinium ashei; Vaccinium corymbosum; Vaccinium virgatum; Varietal selection. Specialized plant breeding, plant breeding aims; deacclimation; Small fruits; Cold resistance; northern highbush; Hybrid; Tolerance; Vaccinium ashei; Vaccinium corymbosum; Genotype; freezing tolerance; rabbiteye; Dicotyledones; Blueberry; Angiospermae; Genetic improvement; Spermatophyta; Ericaceae; southern highbush; Frost resistance
• ISSN: 0179-9541; 1439-0523
• DOI: 10.1111/j.1439-0523.2008.01586.x

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 x 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.