2002 B493×QAL Ver2 B493

The B493 × QAL F2 population was used for mapping STS markers. B493 is a dark orange USDA inbred carrot and QAL is a white wild carrot (D. carota var. carota). The population evaluated was derived from crossing a single B493 plant with a single QAL plant in Madison, WI, in 1989. A single F1 plant was self-pollinated to produce the F2 generation used for mapping. A total of 183 F2 plants grown in field conditions in 1998 were included in the study.

Genotype data for the putative carotenoid structural genes was added to the map data generated by Santos (2001), which consisted mostly of AFLP markers. MAPMAKER 3.0 was used for map construction. Dominant markers from a single parent linked in coupling were used in conjunction with all codominant markers. The two-point command was used to establish linkage groups at a LOD of 4.0. One or two codominant markers per group were assigned as anchor loci in the initialization file. Markers were assigned to linkage groups using the assign command. Three-point analysis was then performed for each linkage group followed by the order command to develop a framework map. Remaining markers were added using the place command. Markers that still remained unplaced were added using the try command. The linkage group numbering of Santos (2001) and Santos and Simon (2002, 2004) was retained.

Separate maps for each parent of the cross were generated consisting of a mixture of only codominant and coupling phase dominant markers. This map corresponds to the B493 parent.