Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2002
Publication Date: 8/5/2002
Citation: MAHAMA, A.A., LEWERS, K.S., PALMER, R.G. GENETIC LINKAGE IN SOYBEAN: CLASSICAL GENETIC LINKAGE GROUPS 6 AND 8. CROP SCIENCE. 2002. V. 42. P. 1459-1464. Interpretive Summary: A roadmap of genetic characteristics is called a linkage map. It shows not only what genetic characteristics are close together (or far apart), but gives you an estimate of the closeness (linkage). In soybean, we worked with genetic characteristics of linkage groups 6 and 8. We showed that certain genetic characteristics of 6 and 8 were actually linked to each other. This means that linkage groups 6 and 8 are actually one large linkage group. Mathematical estimates of the degree of closeness were calculated for all pairwise combinations. This information will benefit scientists in the reassignment of linkage groups, ordering of genetic characteristics, and enhancement of molecular mapping of linkage groups.
Technical Abstract: Mapping mutants of classical linkage groups 6 and 8 (CLGs 6 and 8) in soybean can enhance the identification of important agronomic traits. Genetic data suggest that CLGs 6 and 8 may belong to the same linkage group. Our objectives were to verify whether CLGs 6 and 8 are the same or different, and to determine the correct order of loci involved. Genotypes containing mutants of CLGs 6 and 8 and mutants of other CLGs were crossed in various combinations. Data for the different characters were collected from F2 and F2:3 families. Recombination values confirmed that CLG 6 characters, Df2 and Y11 were linked (R = 27.0 +/ 5.9), Df2 was linked to Ms1 (CLG 8) (R = 24.8 +/ 1.2) and to W1 (CLG 8) (R = 36.4 +/ 1.3), and Y11 was linked to Ms1 (R = 31.7 +/ 1.4). F2 data suggested that Y11 segregated independently of W1:F2:3 data indicated the two were linked (R = 38.4 +/ 3.2). Our data indicated that CLGs 6 and 8 belong to the same linkage group, which is molecular linkage group F (MLG F), and on chromosome 13, Y11 and Adh1 are at the ends of the chromosome segment studied, and Y23 is located between Ms6 and St5. Recombination values among the other loci of CLG 8, and between them and loci of other CLGs were consistent with published values. This information will be useful in the reassignment of CLGs, ordering of loci, and enhancement of molecular genetic linkage mapping in soybean.