CONVERSION OF AN AFLP FRAGMENT LINKED TO THE CARROT Y-2 LOCUS TO A SIMPLE, CODOMINANT, PCR-BASED MARKER FORM

Recent advances have expanded the potential usefulness of molecular te chniques for plant genetic research. AFLP is a powerful technique, all owing rapid and reliable analysis of multiple, potentially polymorphic sites in a single experiment. Because AFLP technology requires no a p riori knowledge of genome structure or preparation of molecular probes , it is immediately useful for a wide variety of plant species. Howeve r, because AFLP markers are dominant, costly, and technologically dema nding, the technique has limited application for large-scale, locus-sp ecific uses. In carrot, the Y-2 locus controls carotene accumulation i n the root xylem core. Although carrot is an important source of dieta ry carotene, little is known about the regulation and biosynthesis of carotenes in carrot. We identified six AFLP fragments linked to the Y- 2 locus through a combination of F-2 mapping and bulked segregant anal ysis. We have developed a procedure for generating simple, codominant, PCR-based markers fi om dominant AFLP fragments using a Y-2-linked AF LP fragment as a model. Our converted marker requires only a simple PC R followed by standard agarose gel electrophoresis. It is rapid, simpl e, reliable, comparatively inexpensive, codominant, and non-radioactiv e. Conversion of AFLP fragments to forms better adapted to large-scale , locus-specific applications greatly expands the usefulness of this m olecular technique.