ARS | Publication request: LINKAGE RELATIONSHIPS AMONG MOLECULAR MARKERS AND STORAGE ROOT TRAITS OF CARROT (DAUCUS CAROTA L. SSP. SATIVUS)

Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 28, 1998
Publication Date: N/A

Interpretive Summary: The genetic improvement of carrot is impeded by the lack of a genetic map since, without a map, we do not know the genetic relationship among important traits. This manuscript documents the largest genetic map of carrot to date. Included are both molecular markers, which are easy to evaluate but only can be scored in the laboratory, and 3 genetic traits expressed in the storage root - purple root color, yellow root color, and type of root sugar. With this genetic map of carrot, we now can begin to better understand the genetic control of characteristics of carrot important for growers and consumers including yield, shape, disease resistance, flavor, and nutritional quality.

Technical Abstract: A 109-point linkage map consisting of three phenotypic loci (P1, Y2 and Rs), six Restriction Fragment Length Polymorphisms (RFLPs), two Random Amplified Polymorphic DNAs (RAPDs), 96 Amplified Fragment Length Polymorphisms (AFLPs), and two Selective Amplification of Microsatellite Polymorphic Loci (SAMPL) was constructed for carrot (Daucus carota L. ssp. sativus; 2n=2x=18). The incidence of polymorphism was 36 percent for RFLP probes, 20 percent for RAPD primers, and 42 percent for AFLP primers. The overall incidence of disturbed segregation was 18 percent. Linkage relationships at LOD score 4.0 and 0=0.25 indicated 11 linkage groups. The total map length was 534.4cM and the map was clearly unsaturated with markers spaced at 4.9cM. AFLP P6B15 was 1.7cM from P1, AFLP P1B34 was 2.2cM from Y2, and AFLP P3B30XA was 8.1cM from Rs.