Developing molecular resources for carrot breeding

SIMON, P. W.; CHUNG, S.-M.; CAVAGNARO, P. F.; GRZEBELUS, D.

Conferencia; 32nd International Carrot Conference; 2007

Genetic improvement of carrot became more focused and intensified with the application of CMS discovered 60 years ago.  Since that time carrot breeders have utilized the broad diversity of carrot germplasm combined with an expanding knowledge of carrot genetics to develop high value modern cultivars.  With the addition of hundreds of molecular markers to the carrot linkage map in the last 20 years, breeders have begun using marker-assisted selection.  Most recently we have begun developing and adding microsatellite markers to the carrot linkage map. To accelerate the development of molecular resources for carrot breeders, the plastid and mitochondrial genomes have been completely sequenced and a BAC library representing 11-fold coverage of the carrot genence has been synthesized.  To date we have identified over 50 BAC clones for 25 mapped genes including Mj-1 nematode resistance, Rs sugar type, Rf petaloid CMS restoration, and carotenoid QTLs and biosynthetic genes.  Over 20 BAC clones with the DcMaster transposons have also been identified.  Fewer than 300 carrot ESTs have been deposited in GenBank. As we develop more carrot ESTs and microarrays carrot breeders can tag more traits.