AFLP Markers Identify \u3cem\u3eCornus florida\u3c/em\u3e Cultivars

Amplified fragment length polymorphism (AFLP) markers were generated from genomic DNA of seventeen flowering dogwood (Cornus florida) cultivars and lines and four duplicate samples. Fragments were analyzed on a Beckman Coulter CEQ™ 8000 Genetic Analysis System. AFLP fingerprints were converted to binary data (1=fragment present, 0=fragment absent) by the CEQ AFLP analysis program. A bin width of one nucleotide and a y-threshold of 15,000 relative dye signal were used to eliminate background noise and other weak peaks. All binary data were manually checked and verified and corrections were made when necessary. Cultivar specific markers were identified for all cultivars except three. Three drafts of a dichotomous cultivar identification key were constructed based on the corrected, verified binary data and the cultivar specific peaks. Two independent AFLP analyses were performed on four and three unknown dogwood samples to test the cultivar identification keys. In both cases, all unknowns except one were identifiable by the dichotomous keys, although in some cases by one key or the other, indicating the need or possibility of several keys. Intracultivar variation was observed in the duplicate samples. Binary data were analyzed by NTSYSpc. A similarity index was calculated and visualized with a tree of genetic distance. This database of AFLP markers can serve as a foundation to which other cultivars can be added and can be used in breeding applications, patent protection and in future projects, such as mapping the Cornus genome