Tuesday, November 6, 2007 - 10:15 AM
177-4

Soybean Genomics: Making Key Discoveries in the ‘Forrest'.

David Lightfoot, Southern Illinois University, Southern Illinois University, Dep. of Plant & Soil Science, Carbondale, IL 62901

‘Forrest' and derived soybean cultivars ‘Hartwig' and ‘Ina' have saved US growers billions in crop losses due to the set of resistances programmed in the genome. Further, because Forrest grows in the north-south transition zone, breeders have used the genome as a bridge to introduce a great deal of quantitative genetic variation from the southern to northern US gene pools. Over the past decade community investment in Forrest genomics has provided a massive tool set; a dense genetic map; three RIL populations (96>n>975); two hundred NIL populations; 115,220 BACs and BIBACs; a physical map; 3 different minimum tiling path (MTP) sets; 25,123 BAC end sequences (BES) encompassing 18.5 Mbp from the MTPs; a map of 2,408 diploid and 2,104 polyploidy regions; a map of homeologous relatioships; a set of stress resistance gene arrays; methods for transformation; methods for RNAi; and a Tilling resource for directed mutant isolation. Genes underlying loci isolated from Forrest derived BACs include candidates for resistance to nematode (Rhg4 and rhg1), resistance to Phytophthora sojae (Rps5), resistance to Pseudomonas syringae (Rps1) and resistance to Fusarium virguliforme (Rfs2) and nodulation (GmNark, GmNod GmCyk1). Additional loci for seed yield, seed composition as well as resistances to 3 biotic stresses, 4 fungal species and 3 nematode species are unpublished. In combining desired characters, the structure of chromosomes appears to be pivotal to the special qualities of the Forrest genome. Genes underlying many quantitative and qualitative loci are targeted for isolation in the laboratories of the worldwide collaborator group. There have been sufficient BACs sequenced to create a dense public database of new genetic markers for soybean breeders. The SoyGD portal at http:/soybeangenome.siu.edu integrates the chromosome map with the whole genome shotgun sequence, a new community resource that identifies whole genes a partial genome annotation and many thousands of SNP candidates.