Generating Genomic Tools for Blueberry Improvement

Abstract

Because of their recognized health benefits, there has been increased demand and consumption of blueberries in recent years. Great strides have been made in blueberry cultivar development since its domestication using traditional breeding approaches. However, genomic tools that could be used to hasten improvement are lacking. The aim of our Specialty Crop Research Initiative project, funded at the end of 2008, is to develop genomic tools for molecular breeding and assessing genetic diversity of blueberry. Marker-assisted breeding would be particularly useful for combining traits for climatic adaptation with those for improved fruit and nutritional quality in highbush blueberry (Vaccinium corymbosum). Genomic resources being developed include expressed sequence tag libraries, expressed sequence tag-based molecular markers, and genetic linkage maps. Transcriptome sequences have been generated from fruit at different stages of development, flower buds at different stages of cold acclimation, and leaves by 454 sequencing. About 600,000 sequences have been assembled into approximately 15,000 contigs. Markers derived from expressed sequence tags (simple sequence repeats and expressed sequence tag-polymerase chain reaction markers) are being used to identify quantitative trait loci associated with cold hardiness, chilling requirement, and fruit quality traits, in studies of genetic diversity, spatial genetic structure, and gene flow in the wild lowbush blueberry (V. angustifolium), and to construct a phylogenetic tree of Vaccinium species in the section Cyanococcus. Availability of these genomic tools will allow future advances, such as the development of a blueberry microarray to facilitate studying gene expression and the use of marker-assisted breeding. © 2012 Copyright Taylor and Francis Group, LLC.