ARS | Publication request: A Linkage Map for Flowering Dogwood (Cornus florida L.) Based on Microsatellite Markers

Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 2, 2008
Publication Date: October 22, 2008
Citation: Wang, X., Wadl, P.A., Rinehart, T.A., Scheffler, B.E., Windham, M.T., Spiers, J.M., Johnson, D.H., Trigiano, R.N. 2008. A linkage map for flowering dogwood (cornus florida l.) based on microsatellite markers. Euphytica.

Interpretive Summary: Flowering dogwood, native to Eastern North America, is ornamental tree that plays an important role in the U.S. nursery industry. Over 100 cultivars have been released in the U.S. in the last decades. `Appalachian Spring¿ and `Cherokee Brave¿ are popular cultivars exhibiting differing phenotypes. `Appalachian Spring¿ has large white-bracts in the spring and deep green leaves that turn scarlet in fall . In contrast, `Cherokee Brave¿ has red or pink bracts in the spring and green leaves that turn fiery red in the fall. The aim of this work was to build a microsatellite marker-based genetic linkage map of flowering dogwood. This initial linkage map will facilitate the location of genes of interest and subsequently permit marker-assisted selection in our breeding program for flowering dogwood. The release of the first linkage map in flowering dogwood will provide the basis for identification and cloning of important genes and QTLs that are beneficial to ornamental industry.

Technical Abstract: A genetic linkage map of flowering dogwood (C. florida L.) was constructed using 94 individuals derived from a cross of two F1 trees designated 97-6 and 97-7, which were originally from a cross between `Appalachian Spring¿ and `Cherokee Brave¿. Out of approximately 800 SSR loci examined, 271 were polymorphism between `Appalachian Spring¿ and `Cherokee Brave¿, but were monomorphic between 97-6 and 97-7. These 271 segregating markers were screened to build a linkage map for flowering dogwood. Eleven linkage groups were obtained with a log-of-odds (LOD) value of 6.0 using JoinMap® 4.0 software. This linkage map consisted of 255 SSR loci, spanned a total of 1175 centimorgans (cM) with an average internal distance of 4.6 cM. Several larger gaps and slight clustering of markers were present on this linkage map. This is the first linkage map of flowering dogwood and will be fundamental tool for new gene identification and marker-assisted selection in our flowering dogwood breeding program.