Breeding for Resistance to Rust Diseases and Gene Stewardship

Gene stewardship requires collaboration between crop improvement scientists, seedsmen, agronomists, farmers, end-users, and consumers.  Each one of these groups has its own language, concepts, and principles.  Our understanding of gene stewardship at each level is deficient if we cannot relate the topic to, at least,adjoining groups.  For example, research results may be too trivial if they cannot be related to a higher organizational level.  Likewise, results may be simply descriptive if they cannot be related to a lower, more specialized level.   Cereal rusts are the most widely and historically studied of all crop diseases.  Contributing to this is the coevolution of the host and pathogen, the importance of the crops for human nutrition, the pervasive occurrence of the diseases nearly where ever the crops are grown, and the explosive epidemic potential of the diseases.  It is likely that one breeding approach to sustainable, durable rust resistance will not be effective under all circumstances and environments.  So, it may be likely that a diversity of approaches to gene stewardship by all groups will have a greater chance at long-term effectiveness.  Much care must be taken by=cereal crop improvement scientists to develop more effective techniques and strategies to extend the useful life of rust resistance genes.  Examples will be given to perhaps reassess how major-effect rust resistance genes are handled in breeding programs and how the resulting varieties are deployed.  The general conclusion is that diversification at all the mentioned group levels may have the best chance of safeguarding our genetic resources.