Submitted to: Annual International Plant & Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/11/2003
Publication Date: 1/11/2003
Citation: LI, L., O'HALLORAN, D., VREBALOV, J., GARVIN, D.F. HIGH-RESOLUTION GENETIC MAPPING OF OR, A GENE THAT INDUCES BETA-CAROTENE ACCUMULATION IN CAULIFLOWER (BRASSICA OLERACEA L. VAR. BOTRYTIS). Annual International Plant & Animal Genome Conference. 2003. p. 194.
Technical Abstract: The cauliflower Or gene is a semi-dominant, single-locus mutation that causes the accumulation of beta-carotene in various tissues of the plant, turning them orange. To elucidate the molecular basis of Or in the regulation of carotenoid accumulation in the plant, we initiated the isolation of Or by map-based cloning strategy. Using bulked segregant analysis in conjunction with AFLP analysis, we identified 10 AFLP markers closely linked to Or. Three of the flanking markers were converted into locus-specific PCR-based SCAR markers. These markers were employed for the analysis of a large mapping population consisting of 1670 F2 individuals. High-resolution mapping of these Or-linked markers placed two of them at 0.8 cM and 1.0 cM apart from the Or locus on one side, while the other marker flanked the gene at a distance of 2.3 cM on the other side. A large-insert BAC library has been constructed using genomic DNA from the Or plants to facilitate the positional cloning. This Or BAC library comprises 60,288 clones with an average insert size of 110 kb. Based on the estimated genome size of cauliflower, the Or BAC library represents an over 10-fold coverage of the genome. Screening of the BAC library with the closely linked marker resulted in the identification of new markers closer to the Or gene. Currently we are in the process to establish a BAC contig that spans the Or locus.