Different cultivars of the soybean (Glycine max (L.) have both resistance to the leaf scorch known as Sudden Death Syndrome (SDS) and to the infection and root rot by the causal organism, Fusarium virguliforme (ex. F. solani f. sp glycines). Several lines of evidence indicate the syndrome is composed of two diseases. Thirteen loci have been identified from analysis of 7 different crosses. Resistance loci in ‘Hartwig' and Forrest, resistant cultivars clearly showed different loci underlie root resistance and leaf scorch resistance (C2, F, I and upper G for scorch, lower G and D2 for root rot). The two disease component must be addressed separately. Environment is a major factor as shown by the fact that additional loci underlie SDS resistance in indeterminate cultivars in the US, Forrest derived cultivars in south America and in Thailand. Major physiological and growth effects can be mistaken for SDS resistance loci. Transcript abundance analysis of roots in response to F. virguliforme shows an orthologous set of transcripts accumulate during infection of resistant soybean cultivars and Arabidopsis thaliana. In both cases the genes were known to be stress related. Therefore, A. thaliana can be used to test transgenes and mutants in candidate genes. Candidate gene identified to date include an ascorbate peroxidase (C2) that is being TILLED and a receptor like kinase (G) that has been used to generate stable transbenic soybeans. Identification of the genes and loci conferring SDS resistance has provided options to breed improved cultivars with resistance to SDS. The information will also be used to update the current genome map at Soybase and SoyGD. Iqbal et al., Theor. Appl. Genet. 110:1429-1438; Kassem et al., 2006 Theor Appl Genet 113:1015-1026; Kazi 2007 Theor Appl Genet 114: Njiti and Lightfoot 2006 Can J Plant Science 41:83-89