ARS | Publication request: Molecular mapping of cg1, a gene for resistance to anthracnose (Colletotrichum sublineolum) in sorghum

Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: January 13, 2007
Publication Date: January 13, 2007
Citation: Ramasamy, P., Menz, M.A., Mehta, P.J., Katile, S., Gutierrez Rojas, L.A., Klein, R.R., Klein, P.E., Prom, L.K., Schlueter, J.A., Rooney, W.L., Magill, C.W. 2007. Molecular mapping of Cg1, a gene for resistance to anthracnose (Colletotrichum sublineolum) in sorghum [abstract]. Proceedings of Plant and Animal Genomes XV Conference, January 13-17, 2007, San Diego, California. Paper No. P371.

Technical Abstract: Anthracnose, caused by the fungus Colletotrichum sublineolum (anamorph C. graminicola), is one of the most destructive diseases of sorghum and has been reported in most areas where the crop is grown. Several control strategies have been developed but host plant resistance has been regarded as the most effective strategy for disease control. To this end, a dominant gene (Cg1) for resistance to the pathogen has been identified by conventional genetic analysis in a cross between ‘SC748-5’ (resistant parent, Cg1Cg1) and ‘BTx623’ (susceptible parent, cg1cg1). To identify molecular markers linked with the Cg1 locus, F2:3s plants derived from the BTx623 by SC748-558 cross were analyzed with ninety eight AFLP primer combinations. Four AFLP markers cosegregating with disease resistance were identified, and all four AFLP markers have been previously mapped to the end of sorghum linkage group SBI-05. Sequence scanning of BAC clones spanning this chromosome 05 region revealed a polymorphic SSR (Xtxp549) that mapped within 3.6 cM of the anthracnose resistance locus. To examine the efficacy of Xtxp549 for marker-assisted selection, thirteen unique advanced breeding lines derived from crosses with sorghum line SC748-5 were genotyped. In twelve of the thirteen lines, Xtxp549 correctly tagged the Cg1 locus suggesting that Xtxp549 and AFLP Xtxa6227 could be useful for marker-assisted selection and for pyramiding of Cg1 with other genes conferring resistance to C. sublineolum in sorghum.