Submitted to: Nematology - Abstracts Only
Publication Type: Abstract Only
Publication Acceptance Date: June 8, 2002
Publication Date: N/A
Technical Abstract: Soybean cyst nematode (SCN), Heterodera glycines, was found in the U.S.A. in 1954, and breeding programs for resistance soon were initiated. The source of resistance in the first resistant cultivars was Peking, which was obtained in China. Subsequent sources of resistance incorporated into in commercial cultivars include PI88.788, PI90.763, PI209.332, all of which also originated in China. The high level of genetic variability within and among populations of SCN has proved problematic to soybean breeders and to farmers. In 1991 germplasm was released that incorporated resistance from PI437.654, which is highly resistant to most populations of SCN. Classical breeding techniques were used exclusively until the late 1990's when marker assisted selection using PI437.654 resistance was developed and is now being utilized in several breeding programs. Genes, rhg1 - rhg3, and Rhg3 - Rhg5, have been reported to be involved in expressing resistance in soybean to SCN. Some genes are linked and multiple alleles may be involved in expressing resistance. Monoculture of resistance has not proven durable, but gene deployment may offer long-term sustainable control of SCN.