Transcriptome Sequencing Of Flowering Dogwood: Gene Discovery and Marker Development

Ornamental crops represent significant contributions to the global economy. However, development of genetic resources for woody ornamental species has lagged behind agronomic crops. Recent advances in next generation sequencing technologies have enabled the development of genetic resources for ornamental crops. Cornus florida, or flowering dogwood is self-incompatible tree species that is native to Eastern North America and is important to the U.S. nursery industry. To develop genomic resources for gene and marker discovery, RNA was isolated from leaves and bracts from ‘Appalachian Spring’ and ‘Cherokee Brave’ and combined in a partially normalized cDNA library optimized for the Roche/454 Titanium platform. Sequencing on one plate yielded over 1.6 M reads and these were assembled de novo into 42,946 isotigs. With approximately 26,000 unique genes sequenced there is substantial coverage of the C. florida transcriptome, and an annotation survey based on homology to sequences in poplar, grape and arabidopsis will be presented. We detected over 5,000 simple sequence repeats (SSRs) and developed thousands of SSR primers for use in future genetic studies.