The genus Glycine comprises two distinct sugenera: Soja , which includes the soybean and its wild progenitors, and Glycine , a diverse group of primarily Australian perennial species. Among this latter group, at least six distinct allopolyploid lineages have been identified and characterized as belonging to the Glycine tomentella polyploid complex. Previous work on cytology, isozymes, rDNA RFLPs, and the single copy nuclear gene histone H3-D have revealed the diploid progenitors of these hybrids. Most recently, the nrDNA ITS repeats have been obtained for these polyploids as well, so that sequence data are now available from a total of four nuclear loci (2 homoeologues from 2 genes). Highly congruent interlocus patterns of relationship between polyploid and diploid haplotypes reveal that this complex includes several distinct yet cryptic polyploid lineages not previously identified. In addition, characterization of polyploid chloroplasts suggests that most of the lineages appear to have evolved at least twice. These data provide a more complete and highly complex history of polyploid speciation within the genus Glycine .

Key words: cpDNA, Glycine tomentella, histone, Leguminosae, nrDNA ITS, polyploidy