ARS | Publication request: DEFINING SUNFLOWER LINKAGE GROUP ENDS WITH THE CONSERVED TELOMERE SEQUENCE-DERIVED TRAP MARKERS

Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: October 15, 2004
Publication Date: January 13, 2005
Citation: Hu, J., Chen, J., Berville, A., Vick, B.A. 2005. Defining sunflower linkage group ends with the conserved telomere sequence-derived TRAP markers. Plant and Animal Genome Conference Proceedings. Plant and Animal Genome XIII Conference, January 15-19, 2005, San Diego, CA. Available: http://www.intl-pag.org/13/abstracts/PAG13_W227.html

Technical Abstract: We are using TRAP (Targeted Region Amplification Polymorphism) markers and recombinant inbred lines (RILs) in sunflower genome mapping, with the ultimate goal of integrating maps of molecular markers and important economic traits. Several independent linkage maps have been published for the sunflower genome, using various types of molecular markers. The alignment of linkage groups is possible by the common markers mapped in different maps. However, the actual or physical ends of the linkage groups are unknown because each linkage group of the published maps starts and ends with the polymorphic markers at the outermost positions. Based on the fact that the telomeres of most higher plants are composed of long stretches of short, guanine-rich repeats [TTTAGGG]n, we used an oligo of 5'-AACCCTAAACCCTAAACC-3' as the fixed primer in TRAP to generate markers near the telomeres. This primer, in combination with other arbitrary TRAP primers, successfully amplified many polymorphic markers in two RIL populations. A small proportion of the markers mapped to the most distal positions of different linkage groups of a map constructed from a population of 129 RILs derived from 83HR4 x RHA345, and comprising over 200 TRAP markers in 17 linkage groups. The endpoint positions of these markers was confirmed by using the DNA and mapping data of the published 92 RILs of a second population derived from HA821 x HA801, for which over 400 SSR markers had been mapped (Tang et al 2003). Sequence analysis of these linkage group endpoint markers is underway.