Plant & Animal Genomes XIII Conference

January 15-19, 2005
Town & Country Convention Center
San Diego, CA

Cataloging Homeologous Genomic Regions Of The Duplicated Soybean Genome By Physical Map Analysis.

J Shultz , S Yaegashi , K Zobrist , Chet Langin , MJ Iqbal , DA Lightfoot

  Genomics Core Facility, Southern. Illinois University, Carbondale, IL62901.USA. ga4082@siu,edu

Homeologous regions can be detected in soybean genomic DNA with most markers. Contigs have at least one homeologous region where sequences homologous to both microsatellite primers lie in order along chromosomes. Homeologs to microsatellite markers vary in number from 2 (33%), 3 (13%), 4 (10%), 5 (6%) to more than 6 (3%). Band size variations are often small or absent so that extensive DNA sequence around marker anchors (<10,000 bp) is often necessary to distinguish homeologs. Homeology varies by chromosome from A2 with 14 homeologous regions on other chromosomes to D1BW with none. K, J, G and D1AQ have 9; H and E have 7, O and C2 have 5, N, L, A1, B1 have 4, M, I, F, D2, C1 and B2 have 2. Presented is a complete set of 20x20 (reciprocal and self) linkage group comparisons. Paralogs are inferred from QTL for identical traits that are positioned in homeologous regions. Trait maps are re-examined in light of the new map of homeologs. We conclude one must be conservative in assigning both QTL and BACs to linkage groups by marker amplification alone. Supported by NSF project #9872635