Submitted to: Bean Improvement Cooperative Proceedings
Publication Type: Proceedings
Publication Acceptance Date: February 20, 2004
Publication Date: April 10, 2004
Citation: Miklas, P.N., Hu, J., Grunwald, N.J. 2004. Potential application of trap markers for tagging disease resistance traits in common bean. Proceedings of the Bean Improvement Cooperative, Oct 27-29, Sacramento, CA, 2003. In Annual Report Bean Improvement Coop. 47:79-80. Technical Abstract: The TRAP (Target Region Amplified Polymorphism) technique is a simple but powerful PCR-based system useful for generating polymorphic markers around targeted candidate gene sequences. TRAPs for disease resistance genes in common bean were targeted in this study. Two mapping population were used to generate and map TRAP markers. The RIL (recombinant inbred line) mapping population BAT 93/Jalo EEP 558 (BJ) was obtained from P. Gepts (University of California-Davis). The BJ population has been widely used to integrate common bean linkage maps. The Dorado/XAN 176 RIL (DX) population was obtained from J. Beaver (Univ. of Puerto Rico-Mayaguez) and has been used previously to map loci conditioning resistance to diseases caused by bacterial, fungal, and viral pathogens in common bean. For the DX population 21 TRAPs were generated from eight multiplex PCR reactions (1.3 TRAPs per reaction). This low level of polymorphism is due to the relatedness of the Dorado and XAN 176 parents, both predominately of Race Mesoamerican origin. Conversely, for the BJ population derived from a wide cross between parents from the Middle American and Andean gene pools, 107 TRAPs were generated from eleven PCR reactions (9.7 TRAPs per reaction: four multiplex and three simplex). For the 21 TRAPs in DX, eight were unlinked, four incorporated into existing linkage groups, and nine formed three linkage groups of 2, 3, and 4 TRAPs. Three of the partial linkage groups consisting of just TRAP markers and two of the unlinked TRAP markers detected new QTL. For the BJ population, 88 of the 107 TRAPs mapped to the eleven linkage groups, ranging from 3 to 12 per linkage group. The TRAPs tended to cluster and some mapped in the vicinity of resistance gene loci (data not shown). Overall, these preliminary data suggest that TRAPs will be useful for tagging and mapping disease resistance traits in common bean.