Dwarfism in Rabbiteye Blueberry

Although southern highbush ( Vaccinium sp.) is replacing rabbiteye ( Vaccinium ashei L.) blueberry, rabbiteye will continue to be grown on marginal soils of the southeastern United States. Dwarfism or short, compact growth habit is a trait that could be used to reduce labor costs in rabbiteye blueberry production. Parental backgrounds, and flowering and fruit traits were studied in seven Mississippi (MS) and five Georgia (T) selections. Six of the MS selections are available for propagation and bloom late enough that cold damage should not be a problem. Four (MS63, MS454, MS546, MS891) of the six have acceptable fruit quality and will be used in breeding. Ethel and MS134 were the only known dwarf ancestors, with Ethel, Myers, Black Giant, and Tifblue (Ethel × Clara) dominating the parental background. Based on the variation in growth habit and ancestries, it would appear that Ethel has several genes for dwarfism and multiple allelic interactions are involved, similar to what Garvey and Lyrene found (1987). Future breeding will include crosses of MS63, MS454, MS546, and MS891 with germplasm outside of the common ancestors, to broaden the genetic base of the dwarf rabbiteyes.