Poster # 504

Ahmed Charif^1,2, Fang Wang^1,2, Tatiana Danilova¹, Navin Shrestha^1,2, Yueqiang Leng³, Shaobin Zhong³, Zhao Jin⁴, Deanna Funnell-Harris¹, Katherine Frels², Stephen Wegulo⁵, Elias Elias⁴, Steven Xu⁶, Mike Giroux⁷ and Xiwen Cai^1,2
1. USDA-ARS, Wheat, Sorghum & Forage Research Unit, Lincoln, NE 68583, USA
2. Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE 68583, USA
3. Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA
4. Department of Plant Sciences, North Dakota State University, Fargo, ND 58108, USA
5. Department of Plant Pathology, University of Nebraska, Lincoln, NE 68583, USA
6. USDA-ARS, Crop Improvement and Genetics Research Unit, Western Regional Research Center, Albany, CA 94710, USA
7. Plant Sciences & Plant Pathology Department, Montana State University, Bozeman, MT 59717, USA
Corresponding Author: PH: 402-326-4055; Email: xiwen.cai@usda.gov

Charif, Ahmed

acharif2@unl.edu

Fusarium head blight (FHB) remains a persistent threat to durum wheat production, particularly due to the limited availability of effective resistance genes and the susceptibility of elite cultivars. In this study, we incorporated the Thinopyrum elongatum-derived resistance gene Fhb7^The2 into four U.S. durum wheat cultivars, ND Riveland, Divide, MTD18348, and Miwok using a marker-assisted backcrossing breeding pipeline. Each cultivar was crossed with WGC002 (Fhb7^The2 donor) and backcrossed four times to develop near-isogenic lines carrying Fhb7^The2. FHB severity was assessed under controlled greenhouse conditions at 14- and 21-days post inoculation (DPI), and in the field at 21 days post flowering using corn spawn inoculation. Fusarium-damaged kernel (FDK) percentages were visually scored from greenhouse-harvested seed. Across all environments, the introgression lines demonstrated a consistent and significant reduction in FHB severity and FDK compared to their recurrent parents. For instance, Miwok- Fhb7^The2 showed a dramatic decrease in FHB severity (5.77% vs. 49.55% at 14DPI_GH) and FDK (17.52% vs. 82.72%) compared to Miwok. Similar results were observed in Divide- Fhb7^The2 (5.82% vs. 35.59%; 7.19% vs. 68.33%), MTD18348- Fhb7^The2 (6.51% vs. 38.40%; 12.07% vs. 70.76%), and ND Riveland- Fhb7^The2 (5.09% vs. 26.39%; 6.08% vs. 41.52%). These results were statistically significant (p < 0.05) and consistent across greenhouse and field trials. The four recipient cultivars represent a diverse genetic and agronomic background: ND Riveland and Divide are high-yielding, regionally adapted cultivars in North Dakota; MTD18348 is a Montana-bred rainfed variety with strong pasta quality; and Miwok is a low-cadmium desert durum tailored for export markets. Despite their differences, all responded positively to Fhb7^The2 introgression, with no observable agronomic penalties. This study confirms the broad utility of Fhb7^The2 in durum wheat breeding and highlights its potential to enhance FHB resistance across diverse genetic backgrounds. The monogenic nature of the resistance and the absence of deleterious effects from the alien translocation make Fhb7^The2 an effective gene for accelerating resistance breeding in durum wheat. Its deployment could substantially reduce disease-related losses and improve food safety in durum production systems.

© Copyright 2025 by individual authors. All rights reserved. No part of this abstract or paper publication may be reproduced without prior permission from the applicable author(s).