Conversion of an AFLP fragment linked to the carrot Y₂ locus to a simple, codominant, PCR-based marker form

Recent advances have expanded the potential usefulness of molecular techniques for plant genetic research. AFLP is a powerful technique, allowing rapid and reliable analysis of multiple, potentially polymorphic sites in a single experiment. Because AFLP technology requires no a priori knowledge of genome structure or preparation of molecular probes, it is immediately useful for a wide variety of plant species. However, because AFLP markers are dominant, costly, and technologically demanding, the technique has limited application for large-scale, locus-specific uses. In carrot, the Y₂ locus controls carotene accumulation in the root xylem core. Although carrot is an important source of dietary carotene, little is known about the regulation and biosynthesis of carotenes in carrot. We identified six AFLP fragments linked to the Y₂ locus through a combination of F₂ mapping and bulked segregant analysis. We have developed a procedure for generating simple, codominant, PCR-based markers from dominant AFLP fragments using a Y₂-linked AFLP fragment as a model. Our converted marker requires only a simple PCR followed by standard agarose gel electrophoresis. It is rapid, simple, reliable, comparatively inexpensive, codominant, and non-radioactive. Conversion of AFLP fragments to forms better adapted to large-scale, locus-specific applications greatly expands the usefulness of this molecular technique.