Submitted to: Bean Improvement Cooperative Annual Report
Publication Type: Research Notes
Publication Acceptance Date: March 3, 2006
Publication Date: May 15, 2006
Citation: Miklas, P.N., Hu, J. 2006. Potential use of trap markers for mapping telomeres in common bean. Bean Improvement Cooperative Annual Report. 49:189-190. Technical Abstract: A characteristic of genetic linkage maps is genomic length measured in centiMorgan (cM) which can be influenced by polymorphism between the parents, number of markers, and recombination frequency. The length of corresponding individual linkage groups varies greatly among maps, and the actual genetic lengths are unknown because each linkage group starts and ends with the polymorphic markers at its outermost positions. Each linkage group corresponds to one chromosome, and each chromosome has two terminal ends called telomeres. Our objective was to pursue the possibility of employing TRAP (Target Region Amplified Polymorphisms) markers to map bean telomeres in order to provide a better estimate of the actual length of linkage groups (chromosomes) and to develop anchor markers to facilitate map integration and alignment of linkage group ends. The TRAP technique used fixed primers based on telomeric DNA of Arabidopsis. There were 45 TRAP markers generated by the four primer combinations in the BAT 93/Jalo EEP558 (BJ) RIL mapping population. Thirty-nine TRAPs where located on the BJ linkage map and six were unlinked. Only two TRAPs mapped to the very end of a linkage group (B3 and B10), and three TRAPs mapped near the end but internal to terminal markers for linkage groups B2, B8, and B9.These preliminary results suggest that the TRAP technique using fixed primers derived from the Arabidopsis-type telomeric repeat may not be useful for mapping telomeres in common bean. However, trying different fixed primers and additional primer combinations is warranted before abandoning the technique altogether given its success in sunflower.