Soybean Genomics: Developments through the Use of Cultivar “Forrest”

Figure 1

Soybean genomic resources and products schematic for Forrest (A) compared to the SoyGD representation (B). Panel A. Germplasm that are exemplars of soybean genetic diversity are shown. Selected germplasm encompass in mapped QTL a wide variety of traits placed on the composite genetic map. BAC libraries exist for many of the germplasm sources. Forrest BACs (shown in black) form the basis of an MICF physical map with 6-fold coverage. A region of conserved duplication (12-fold coverage) is shown on the right of the figure. In this region, fingerprinted clones from two homoeologous linkage groups coalesce. Genetic markers identified in, or derived from, BAC end sequences (BESs) will separate some of the duplicated conserved regions. Genetic markers anchored from map to BAC are of little use in conserved duplicated regions. BACs from diverse germplasm are shown as blue bars. There are 3 levels of DNA sequence envisioned. At level 1, BESs provide a sequence every 10–15 kbp with which to identify gene rich regions for later complete sequence determination (level 2). Arrayed BAC end sequences will be used to identify conserved syntenic regions in the genomes of model plant species. This information will also separate some of the duplicated conserved regions in soybean. Panel B. Shown are the chromosome (cursor), DNA markers (top row of features, red); QTL in the region (second row, blue); coalesced clones (purple) comprising the anchored contigs (third row, green); BAC end sequences (fourth row black); BESs encoding gene fragments (fifth row, puce); EST hybridizations to MTP2BH (sixth row gold); MTP4BH clones (seventh row, dark blue); BESs-derived SSR (eight row, green).