The soybean cyst nematode (SCN), or Heterodera glycines, is the most damaging pathogen to soybean production in North America and 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 have developed in their fields. The widespread lack of diversity for SCN resistance genes utilized and available for farmers in commercial soybean varieties has significantly increased the prevalence of virulent SCN populations across the mid-west (mainly HG 1.2.5.7), and reduced the effectiveness of current sources of resistance. Thus, we have two major research challenges that, when successfully achieved, will enable us to develop more efficient management practices for this pest in the future.
• Nematologists need to 1) identify the SCN genes, and their functionality, required for the adaptation to reproduce on resistant varieties, 2) use these as molecular markers to monitor nematode population shifts in the field in real time, and 3) exploit this knowledge to help plant breeders identify the best resistance gene combinations for short- and long-term nematode management.
• Breeders need to increase the availability of genetically diverse SCN resistance in commercial soybean varieties and work with nematologists to determine the most effective rotation practices that preserve the efficacy of the known sources of SCN resistance.
To address these issues, we are proposing the third year of Phase III of an integrated, collaborative, and multi-state project among plant breeders, molecular biologists, bioinformaticians, and nematologists. Our proposed objectives specifically address the following key research area in the current RFP - Basic and applied research directed at soybean disease, nematode, insect pest and abiotic stress biology, management and yield loss mitigation, including new and emerging threats, of consistent or potentially significant economic impact across the North Central Region - and this proposed research complements funding from federal agencies, as well as respective state and United Soybean Board check-off support. The genetic resources developed and knowledge gained from this project will provide immediate and long-term benefit to soybean producers and researchers in both the private and public sector.