Monica Pennewitt, Iowa State University graduate student, discusses her research on soybean cyst nematode.The soybean cyst nematode (SCN) or Heterodera glycines is the most damaging pathogen to soybean production in North America. Current annual yield losses are estimated at more than $1.2 billion.Though SCN-resistant soybean varieties are available to minimize yield loss, producers are faced with limited options for rotation once virulent SCN populations develop in their fields. The widespread lack of genetic diversity for SCN resistance genes in commercial soybean varieties has significantly increased the prevalence of virulent SCN populations and reduced the effectiveness of current sources of resistance. Therefore, scientists are looking to increase the genetic diversity of SCN- resistant soybean varieties commercially available to producers.