Submitted to: Helia
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/25/2007
Publication Date: 7/1/2007
Citation: Hu, J., Yue, B., Vick, B.A. 2007. Integration of TRAP markers onto a sunflower SSR marker linkage map constructed from 92 recombinant inbred lines. Helia. 30(46):25-36. Interpretive Summary: This paper reports the application of the target region amplification polymorphism (TRAP) marker technique to sunflower genome mapping. The mapping population was the same recombinant inbred line (RIL) population to which we added the telomere-associated TRAP markers in defining 21 of the 34 linkage group ends (telomeres). The markers are potentially useful in tagging important genes located near the telomeres. An additional 220 TRAP markers were generated with 23 primer combinations with fixed primer designed against selected sunflower ESTs showing homology with components of plant disease resistance genes and homeobox genes. These markers integrated well with the mapped SSR markers and are added to the map. The resulting map consists of 980 markers in 17 linkage groups and the total length is 1920 centiMorgan. The added markers are also potentially useful in tagging genes underlying sunflower traits of economic importance.
Technical Abstract: The target region amplification polymorphism (TRAP) marker technique was employed to expand the published sunflower simple sequence repeat (SSR) linkage map constructed from a recombinant inbred population derived from the cross of RHA 280 x RHA 801. A previous report described the mapping of 183 TRAP markers generated by using fixed primers designed against the conserved Arabidopsis-type telomere sequence repeat into the above mentioned map of 577 SSR markers. Thirty-two markers were mapped to the outermost positions of the linkage groups, defining 21 of the 34 linkage group ends. This paper reports the integration of an additional 220 TRAP markers onto the same map. These newly added TRAP markers were generated with 23 combinations with fixed primers designed against selected sunflower ESTs showing homology with components of plant disease resistance genes and homeobox genes. The resulting map consists of 980 markers in 17 linkage groups (LG) and the total length is 1920 centiMorgan (cM). Although the average distance between two markers is less than two cM, there are four gaps larger than 20 cM (one in LG2, one in LG4, and two in LG6). The gaps could be due to the lack of polymorphism between the two parental lines in these chromosome regions with respect to the type of markers used in this study.