Genotypic and Phenotypic Evaluation of Soybean Lines From Glycine Max by Glycine Soja Backcrosses.

Commercial soybean [Glycine max (L.) Merr.] breeding in the U.S. currently relies on a narrow genetic base in which more than half of the genetic contribution, calculated by pedigree analysis, comes from only 5 ancestral lines. For decades, but more intensely in recent years, efforts have been made to incorporate exotic soybean germplasm into the breeding pool. Although wild soybean (G. soja Seib. et Zucc.) is genetically much more diverse than soybean, much less effort has been devoted to utilizing wild soybean in soybean breeding. The objectives of this research are to identify high yielding lines derived from crosses between 5 wild soybean accessions and soybean cultivars; and determine if there are differences in the genetic contributions of each wild soybean parent. The wild soybean parents originated from China and Russia. Each wild soybean was crossed to Williams 82 and the F1 plants were backcrossed to Williams 82. Phenotypic family selection during the inbreeding process was used to develop lines for the first cycle of yield testing. Ten relatively high yielding backcrossed-derived (BC1) lines were selected. Some BC1 lines were backcrossed to Williams 82; some BC1 lines were crossed with each other, and some were crossed to the more current cultivars, IA2052, IA3023, and LN97-15076. Preliminary yield testing of inbred lines from these crosses was used to select 96 high yielding lines from 16 pedigrees in maturity groups III and IV. These experimental lines and all the parental lines were genotyped with 1536 SNP markers in the Universal Soy Linkage Panel 1.0 using the Illumina GoldenGate assay. Yield and other agronomic data were collected in two replication tests at six locations in Ohio, Illinois, Missouri and Nebraska in 2011 and 2012. Preliminary data identified experimental lines that are not significantly different from the recurrent parent for seed yield.