Using Independent Culling to Screen Plant Introductions for Combined Resistance to Soybean Cyst Nematode and Sudden Death Syndrome

Two infectious diseases that cause most yield losses in soybean [Glycine max (L.) Merr.] are soybean cyst nematode (SCN), caused by Heterodera glycines Ichinohe, and sudden death syndrome (SDS), caused by Fusarium solani (Mart.) Sacc. f. sp. glycines (Fsg). Because SCN and SDS have a synergistic effect on yield when they occur jointly in the field, breeders are attempting to develop varieties with dual resistance to these two diseases. Using independent culling as a selection strategy, we screened a set of 31 new soybean plant introductions (PI) that were field evaluated in 1995 at two locations in Southern Illinois. We identified 11 elite PIs that were resistant to SCN race 3, had yellow seed coat, a relatively good field response to SDS, and a moderate seed yield. These superior genotypes can be used as potential parents in soybean breeding programs.