Lessons from a soybean collection

The United States Department of Agriculture (USDA) Soybean Germplasm Collection was established in 1949. Growth of the collection has been uneven throughout its history. Restrictions on germplasm exchanges and collections will likely prevent rapid growth of the collection in the foreseeable future. Because the USDA Soybean Germplasm Collection has limited opportunities to grow and is well evaluated and characterized for both phenotypic and genotypic traits, it is a mature collection. Mature collections will require fewer resources for acquiring, documenting, evaluating, and characterizing accessions which will permit an emphasis on research that will foster increased utilization. Pure lining accessions of self-pollinated species is superior for maintaining genetic diversity. Genetic drift, natural selection, and sample contamination are problems for mixed seed lots. We document unintended changes for this type of accession. Mixed seed lots also limit meaningful evaluation. Research is a critical part of effective germplasm curation. We report successful research within the USDA Soybean Germplasm Collection that identified exotic accessions that contributed haplotypes that increase the yield of the highest yielding cultivars and are absent from the commercially used gene pool of the northern United States. Crosses with wild soybean produced lines that yielded more than the soybean parent. We developed procedures to produce fertile progenies from crosses between soybean and Glycine tomentella and identified derived lines that exceeded the yield of the soybean parent. Research on accessions within the National Plant Germplasm system is critical if the preserved germplasm is to be used to its fullest potential.