ARS | Publication request: Association analysis using SSR markers to identify QTL for seed protein content in soybeans

Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 18, 2007
Publication Date: January 25, 2008
Repository URL: http://hdl.handle.net/10113/16180
Citation: Jun, T., Van, K., Kim, M., Lee, S., Walker, D.R. 2008. Association analysis using SSR markers to identify QTL for seed protein content in soybeans. Euphytica. 162:179-191.

Interpretive Summary: Association analyses provide a method for detecting genes associated with traits based on linkage disequilibrium, (i.e., a higher than expected likelihood that a gene and a molecular marker will be inherited together) in a group of distantly related individuals. This approch has advantages in time and resolution power over more conventional gene mapping studies that depend on analysis of segregation among the progeny of a cross between two inbred parents. A disadvantage of association analysis is that relatively dense marker coverage of the genome is assumed to be necessary for it to work. The research reported here describes an attempt to identify the locations of genes (quantitative trait loci or QTL) associated with soybean seed protein levels using only 150 DNA simple sequience repeat markers to search for genomic regions that were more similar within high-protein and low-protein groups of germplasm accessions than between the two groups. Efforts were made to avoid possible population structure within groups by attempting to diversify maturity groups and geographical origins of the accessions included in each group. Association analysis identified 11 putative QTL's, nine of which are in the regions where protein QTL had already been mapped(suggesting that the technique worked). Two regions, one on LGJ and another on LGM, had not been reported in the literature before and may contain novel QTL. The apparent success of the method was supported by similar results obtained from analysis of independently selected sets of high and low protein germplasm accessions.

Technical Abstract: Five soybean [Glycine max (L.) Merr.] germplasm lines were developed by the Georgia Agricultural Experiment Stations and released in 2005: G95-Ben335 (PI644042), G95-Ben 1818 (PI 644043), G95-Ben2403 (PI 6444044), G95-Ben2448 (PI644045), and G95-Ben4123 (PI644046). They were selected within the productive soybean cultivar 'Benning' (Boerma et al., 1997) with differences in seed protein, seed oil, seed weight or maturity. These lines have utility and parents to develop elite breeding populations or use in the study of genetic and physiological mechaniasms responsible for conditioning the phenotypes of the selected variants within Benning.