Genomic compatibility and inheritance of hexaploid-derived Fusarium head blight resistance genes in durum wheat

Authors: ZHU, XIANWEN - North Dakota State University; Boehm Jr, Jeffrey; ZHONG, XIAOBIN - North Dakota State University; Cai, Xiwen

Submitted to: The Plant Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/29/2021
Publication Date: 6/14/2022
Citation: Zhu, X., Boehm Jr, J.D., Zhong, X., Cai, X. 2022. Genomic compatibility and inheritance of hexaploid-derived Fusarium head blight resistance genes in durum wheat. The Plant Genome. 15(2). Article e20183. https://doi.org/10.1002/tpg2.20183.
DOI: https://doi.org/10.1002/tpg2.20183

Interpretive Summary: Fusarium head blight (FHB) is a devastating disease of bread and durum wheat in the U.S. and worldwide. It can cause significant economic losses of wheat producers when the weather conditions favor the disease development during wheat growing seasons. Disease resistance has been considered the most economically-effective and environmentally-friendly approach to manage this widespread disease of wheat. Multiple FHB resistance genes have been identified and utilized in bread wheat. However, effective sources of resistance to this disease have not been identified in durum wheat, limiting the progress of breeding for FHB resistance in durum. So, we have made effort to introduce FHB resistance genes from bread wheat into durum wheat. Although bread and durum wheat share two of the three wheat genomes, they remain different in their genetic makeup to certain extent, which leads difficulties transferring resistance from bread wheat to durum wheat through plant breeding. In this study, the transfer of FHB resistance from bread wheat to durum were attempt. Two major bread wheat resistance sources acted differently in durum wheat. In addition, durum wheat chromosomes that enhance or suppress FHB resistance were identified using genetic and a unique set of wheat lines. This study demonstrated the challenges of transferring FHB resistance to durum wheat, and provides a framework for the future development of FHB resistance durum cultivars critical to sustainable wheat production in the presence of this disease.

Technical Abstract: Hexaploid-derived resistance genes in wheat exhibit complex inheritance and expression patterns as tetraploid introgressions. This study aimed to characterize the inheritance patterns and genomic compatibilities of hexaploid-derived Fusarium head blight (FHB) resistance genes in tetraploid durum wheat. Evaluation of FHB resistance for F1 hybrids of hexaploid ‘Sumai 3’ crossed with tetraploid and hexaploid wheats indicated that Sumai 3-derived FHB resistance genes exhibit a dominant phenotypic effect seen only in hexaploid hybrids. Alternately, the hexaploid-derived FHB resistance genes from PI 277012 exhibited complete dominance in both tetraploid and hexaploid hybrids. FHB evaluation of the F1 hybrids of Sumai 3 and PI 277012 crossed with ‘Langdon’ (LDN) D-genome substitution lines suggested that chromosomes 2B, 3B, 4B, 5B, 6B, 3A, 4A, 6A, and 7A contain genes that suppress expression of the Sumai 3-derived FHB resistance, whereas chromosomes 4A, 6A, and 6B contain genes required for expression of PI 277012-derived FHB resistance. A wide range of segregation for FHB severity (10-90%) was observed in the F2 generation of Sumai 3 crossed with durum varieties LDN and ‘Divide’, but the distribution of F3 families derived from the most resistant F2 segregants was skewed towards susceptibility. A similar segregation trend was observed in the crosses of PI 277012 with other durum wheats, whereby FHB resistance became slightly diluted over successive generations. These results suggest tetraploid durum wheat contains multiple genes on different chromosomes that positively and/or negatively regulate the expression of hexaploid-derived FHB resistance genes, which complicate efforts to deploy these genes in durum breeding programs.