Poster # 153

Fang Wang^{1, 2}, Ahmed Charif^{1, 2}, Tatiana Danilova², Wei Zhang^{3, 4}, Mingyi Zhang⁴, Shuangfeng Ren⁴, Xianwen Zhu⁴, Shaobin Zhong⁵, Jason Fiedler⁶, Steven Xu⁷, Katherine Frels¹, Stephen Wegulo⁸, Jeffrey Boehm Jr.², and Xiwen Cai^{2, 1}
1. Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE
2. USDA-ARS, Wheat, Sorghum & Forage Research Unit, Lincoln, NE
3. Shanxi Key Laboratory of Minor Crop Germplasm Innovation and Molecular Breeding, Shanxi Agricultural University, Taiyuan, 030031, China
4. Departments of Plant Sciences, North Dakota State University, Fargo, ND
5. Department of Plant Pathology, North Dakota State University, Fargo, ND
6. USDA-ARS, Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Fargo, ND
7. USDA-ARS, Crop Improvement and Genetics Research Unit, Western Regional Research Center, Albany, CA
8. Department of Plant Pathology, University of Nebraska, Lincoln, NE
Corresponding Author: Xiwen Cai, xiwen.cai@usda.gov

Xiwen Cai

A novel allele of the FHB resistance gene Fhb7, designated Fhb7^The2, was identified on chromosome 7E of the diploid tall wheatgrass Thinopyrum elongatum (2n=2x=14, EE), and integrated into the wheat B genome through a small 7B-7E translocation (7BS·7BL-7EL) involving the terminal regions of the long arms. Fhb7^The2 conditions Type II FHB resistance and may detoxify deoxynivalenol (DON) according to a previous report. In addition, the FHB-resistant 7B-7E introgression line does not contain the gene for yellow flour pigment, which is closely linked to the Fhb7 alleles from other sources. The integration of Fhb7^The2 into wheat chromosome 7B and the absence of yellow flour pigment gene in the introgression line make Fhb7^The2 immediately usable in both common wheat and durum wheat breeding without obvious linkage drag. Both STS and SNP-based PACE markers were developed specifically for Fhb7^The2. They are highly diagnostic for the selection of Fhb7^The2 and effective for the introgression of Fhb7^The2 into different classes of wheats. They have been used to deploy Fhb7^The2 in the adapted hard red winter/spring wheat and spring/winter durum varieties through a marker-assisted backcrossing breeding scheme. Starting from the BC₁F₁ generation, the Fhb7^The2-specific PACE marker has been utilized to select Fhb7^The2-positive individuals for further backcrosses. The Fhb7^The2-positive backcross progeny with the highest phenotypic recovery of the respective recurrent parent has been selected for advanced backcrossing. The 7BS·7BL-7EL translocation has been found to transmit in a typical Mendelian fashion over the backcross generations. After 3-4 backcrosses, Fhb7^The2 will be deployed in the adapted common and durum wheat varieties, leading to the development of the new FHB-resistant varieties. Meanwhile, we have been transferring Fhb7^The2 to the major FHB resistance sources ‘Sumai 3’, PI 277012, ‘Wangshuibai’, and ‘Frontana’ following the similar Fhb7^The2marker-assisted backcrossing breeding scheme. Stacking Fhb7^The2 with the major FHB resistance genes may enhance FHB resistance and generate new sources with improved FHB resistance.

ACKNOWLEDGEMENT AND DISCLAIMER

This material is based upon work supported by the Agreement No. 59-0206-7-002 (USWBSI) and the U.S. Department of Agriculture, under Award No. 2019-67013-35750 (NIFA). This is a cooperative project with the U.S. Wheat & Barley Scab Initiative and the National Institute of Food and Agriculture. 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.