Fusarium Head Blight (FHB) is a major disease that can cause severe loss of grain yield and quality of durum wheat in the northern Great Plain of the US. FHB resistance in wheat is a complex trait controlled by many genes. Recurrent selection is an effective way to increase frequencies of favorable resistant alleles and to develop improved germplasm. In this study, three cycles of recurrent phenotypic selection were conducted for reducing FHB severity from 2019 to 2021 in a durum wheat population derived from intercrossing of 15 elite cultivars and breeding lines. The FHB severity was reduced 13.8% from Cycle 0 to Cycle 1 population, and 25.9% from Cycle 1 to Cycle 2 population. Significant negative correlations were found between FHB severity and plant height and between FHB severity and days to flowering in Cycle 0 population, but not observed in Cycle 1 and Cycle 2 populations. Genomic selection (GS) can speed up selection and increase genetic gain in terms of time and cost. A total of 161 S1 families in Cycle 2 population were genotyped using 90K SNP array and obtained 4,614 SNP markers. Using ridge regression best linear unbiased prediction (rrBLUP) model, the prediction accuracy for FHB severity was 0.39 with cross-validation. Our results indicate that recurrent phenotypic selection can improve FHB resistance in durum wheat. Implementing GS in the recurrent selection is possible to further accelerate genetic improvement.

ACKNOWLEDGEMENT AND DISCLAIMER

This project is supported by the U.S. Department of Agriculture (USDA), under Agreement No. 59-0206-0-161. This is a cooperative project with the U.S. Wheat & Barley Scab Initiative (USWBSI). Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the view of the U.S. Department of Agriculture.