Location: Southern Horticultural ResearchTitle: Quantitative trait loci associated with red foliage in Cornus florida L) Author
Submitted to: Molecular Breeding
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/27/2011
Publication Date: 3/1/2011
Citation: Wadl, P.A., Saxton, A.N., Wang, X., Pantalone, V.R., Rinehart, T.A., Trigiano, R.N. 2011. Quantitative trait loci associated with red foliage in Cornus florida L. Molecular Breeding. 27:409-416. Interpretive Summary: Flowering dogwood is a small- to medium-sized deciduous tree that is native to the eastern North America and is a popular ornamental tree grown in the eastern and southeastern United States. Specifically, it is valued for its pink, red or white bracts, brilliant red fall foliage and bright red berries. The US Department of Agriculture Census of Horticultural Specialties concluded that retail and wholesale sales of dogwood account for over $26 million US dollars annually, and of this 74.9% of sales are from eight states (Alabama, California, Illinois, North Carolina, New Jersey, Oregon, Tennessee, Virginia). Sales of dogwood in Tennessee account for 23.2% of the total US sales making dogwood an important ornamental crop to the economy of the state. The recent construction of the first genetic linkage map spanning 11 linkage groups in flowering dogwood using SSRs could facilitate the first QTL analysis in C. florida. In the pseudo F2 mapping population, individuals were observed with foliage colors that were green, red, or a gradation between green and red. We present data collected for three years on this interesting ornamental trait. An initial step in identifying the genes responsible for this trait would be the identification of molecular markers associated with foliage color. Such markers have not yet been reported in flowering dogwood.
Technical Abstract: A segregating pseudo F2 population of 94 individuals of flowering dogwood (Cornus florida L.), together with 255 SSR markers, was used to identify putative quantitative trait loci (QTLs) for foliage color. The foliage color segregated into green- and red-leaved phenotypes and was visually rated for color on five spring dates over three years (2007 – 2009). Repeated measures single-marker analysis of variance (ANOVA) identified four putative QTLs (CF309C, CF792A, CF367B and CF367C) on three linkage groups. Single-marker ANOVA was then used to determine stability of QTLs across years. Identification of different QTLs, a low percentage of phenotypic variance explained by the QTLs detected, and QTL instability over years was detected, providing evidence of the complex genetics for anthocyanin expression in flowering dogwood. The objective of our investigation was to acquire information on the association between molecular markers and foliage color in flowering dogwood in order to improve our understanding of the inheritance of this trait and to make possible early selection of red foliage genotypes in breeding programs.