RESPONSES OF SOYBEAN CULTIVARS AND BREEDING LINES TO RACES OF HETERODERA-GLYCINES

Many new cultivars of soybean (Glycine mas) are released each year. Kn owledge of their relative susceptibility to soybean cyst nematode (Het erodera glycines) is of interest to soybean breeders and those making nematode management recommendations. Two-hundred-eighty-one cultivars and breeding lines of soybean were screened for resistance to isolates of H. glycines races 1, 2, 3, 4, 5, 6, 9, and 14. No cultivar or line (except possibly PI 437654 or cultivars developed from this PI line) had resistance to all of the races tested. Twenty-one cultivars and li nes were resistant to race 1, 5 to race 2, 146 to race 3, 2 to race 4, 4 to race 5, 24 to race 6, and 24 to race 14; some had resistance to more than one race. In addition, several cultivars and lines had moder ate resistance to each of the race isolates tested.