TRANSCRIPTOME SEQUENCING OF FLOWERING DOGWOOD (CORNUS FLORIDA) FOR DEVELOPMENT OF EST-SSRS

To obtain more information on the flowering dogwood genome, a single custom, normalized library for Roche/454 sequencing was prepared and sequenced for bract (‘Cherokee Brave’) and leaf (‘Appalachian Spring’ and ‘Cherokee Brave’) tissue.
The 1,621,644 reads were assembled into 63,029 unique sequences, comprising 42,946 isotigs (26,627 isogroups) and 20,083 singletons.
Also, 5,670 expressed sequence tags (EST) – simple sequence repeats (SSRs) were identified from the data set.
To demonstrate the usefulness of this EST resource for marker development, primers were designed for 2,998 of the EST-SSRs of which 94 were tested for amplification of loci in ‘Appalachian Spring’, ‘Cherokee Brave’, and two F1 breeding lines.
Seventy-five of the loci amplified and 29 were polymorphic, from which 9 of the most poly¬morphic loci were selected and tested using 22 individuals representing 6 dogwood species and an interspecific hybrid.
The number of alleles detected ranged from 3 to 10 and observed heterozygosity was 0.05 to 0.67. Cross species transfer was higher in the big-bracted dogwood species (C. elliptica and C. kousa) than in the non-bracted species (C. alba, C. alternifolia, and C. sericea) and principal coordinate analysis differentiated all of the species.
This work confirms the applicability of flowering dogwood EST-SSRs for the breeding and genetics of flowering dogwood and other Cornus species.
We expect to optimize more EST-SSRs in order to accelerate breeding of flowering dogwood cultivars with improved disease resistance, heat or drought tolerance, and other aesthetically appealing ornamental traits.

II International Symposium on Woody Ornamentals of the Temperate Zone

P.A. Wadl, R.N. Trigiano, T.A. Rinehart, B.E. Scheffler

microsatellites, woody ornamental, expressed sequence tags simple sequence repeats

https://doi.org/10.17660/ActaHortic.2013.990.31