Genetic Control of Cold Hardiness in Blueberry

Winter hardiness in woody perennials depends on the complex integration of two phenological events: endodormancy and development of cold hardiness (cold acclimation; CA) (Powell 1987). Exposure to low temperatures during fall and winter, which plays a role in CA, is also required for breaking endodormancy and resumption of growth the following spring (Scalabrelli and Couvillion 1986). This requirement, called chilling requirement (CR), is genetically determined (Hauagge and Cummins, 1991, Samish, 1954). Although limited in number, most studies indicate that cold hardiness (CH) is a complex trait with polygenic inheritance. Despite their integral role in the life cycle of woody perennials, studies aimed at elucidating genetic control of CH and CR are scarce.