The overall theme of the research reported in this dissertation was to discover and translate new genetic knowledge about genetic resistance of soybean cyst nematode (SCN). The research had three distinct projects. The first project addressed the hypothesis that there are no new QTL from alternate sources of SCN resistance. Five families of Recombinant Inbred Lines (RILs) derived from novel sources of resistance for races 1, 2, 3, and 5 were developed to test the hypothesis. The second and third projects addressed hypotheses based on the results of the first project. The second project addressed the hypothesis that there was no difference between a Traditional Introgression Backcross Design and a design that used Integer Programming coupled with the Predicted Cross Value to introgress multiple QTL from multiple donors into one recipient line. Criteria for comparing the two designs included cost, time and probability of success. The third project is a preliminary assessment of three models to estimate the total number of QTL for SCN resistance. The models were adapted from models developed by statistical ecologists to estimate abundance of species in habitats.