Fusarium head blight (FHB) continues as a threat to spring wheat production in the Upper Midwest in years in which climatic conditions are favorable.  After more than 30 years of intensive breeding effort in the hard red spring wheat region, more than half of the available varieties have at least moderate levels of resistance, but none have complete resistance and even the most resistant materials available today can incur damage when environmental conditions are conducive for an epidemic.  Phenotyping in two inoculated & irrigated nurseries remain the bedrock of our breeding efforts with this disease but have been complimented with genomic prediction and DNA marker selection.  We routinely screen with DNA markers all of our pre-yield trial F₅ lines, between 2,000-3,000 lines per cohort, as well as BC₁ and TC₁plants segregating for Fhb1 and the 5AS QTL.  A training population of ~210 F₅ lines and their 40-50 parents is phenotyped for FHB traits each year and used to predict the remaining lines, helping us to reduce the number of preliminary yield trial candidates sent to and harvested from our winter nursery seed increase.  Using historic data to train FHB genomic prediction models, beyond the previous years’ cohort, has been of limed value. All lines entered in preliminary yield trials and retained for future evaluation undergo phenotypic selection for FHB resistance each year.  After three or more years of FHB evaluation the most resistant lines, including those discarded from variety release consideration due to agronomic or end-use quality deficiencies, are evaluated in the spring wheat regional scab nursery.

ACKNOWLEDGEMENTS

This material is based upon work supported by the U.S. Department of Agriculture, under Agreement No. 59-0206-2-092  This is a cooperative project with the U.S. Wheat & Barley Scab Initiative.  Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author and do not necessarily reflect the view of the U.S. Department of Agriculture.