Location: Cereal Crops ResearchTitle: Effects of durum wheat background on the expression of hexaploid wheat-derived Fusarium head blight resistance genes Author
|Zhu, Xianwen - North Dakota State University|
|Zhong, Shaobin - North Dakota State University|
|Elias, Elias - North Dakota State University|
|Cai, Xiwen - North Dakota State University|
Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/18/2014
Publication Date: 12/7/2014
Citation: Zhu, X., Zhong, S., Xu, S.S., Elias, E., Cai, X. 2014. Effects of durum wheat background on the expression of hexaploid wheat-derived Fusarium head blight resistance genes [abstract]. In: Canty, S., Clark, A., Turcott, N., Van Sanford, D., editors. Proceedings of the National Fusarium Head Blight Forum, East Lansing, MI/Lexington, KY: U.S. Wheat & Barley Scab Initiative, December 7-9, 2014, St. Louis, MO. p. 104-105.
Technical Abstract: Multiple Fusarium head blight (FHB) resistance sources have been identified in common wheat, but an effective source of resistance to FHB has not found in durum wheat. Here we report preliminary results on the effects of durum background on the expression of hexaploid wheat-derived FHB resistance genes. Two FHB-resistant hexaploid wheat accessions, Sumai 3 and PI 277012, were crossed to the durum cultivars 'Langdon' (LDN), 'Divide', 'Grenora', 'Alkabo', and LDN D-genome substitution lines. Also, Sumai 3 and PI 277012 were crossed to three FHB-susceptible hexaploid wheat accessions ('2398', 'Choteau', 'AC Vista', and 'AC Lillian'). All F1's of Sumai 3 with durum exhibited a resistance level similar as or lower than their durum parents, whereas F1's of Sumai 3 with hexaploids exhibited a resistance level intermediate to their parents. Apparently, FHB resistance genes in Sumai 3, including Fhb1, were normally expressed in the F1's with hexaploids, but not in the F1's with durum. The F1's of PI 277012 with durum all exhibited a resistance level comparable to PI 277012, indicating complete dominance of the resistance genes in PI 277012 over the susceptible alleles in durum. Individual homoeologous substitution of D-genome chromosomes for LDN durum chromosomes 2B, 3A, 3B, 4A, 4B, 5B, 6A, 6B, and 7A all augmented resistance levels of the F1's between Sumai 3 and the LDN D-genome substitution lines, suggesting these durum chromosomes may contain genes that suppress expression of the Sumai 3-derived FHB resistance genes in the F1's. Individual substitution of LDN durum chromosomes 4A, 6A, and 6B by their D-genome homoeologs lowered resistance levels in the F1's of PI 277012 with the LDN D-genome substitution lines, whereas individual substitution of other LDN durum chromosomes did not significantly change resistance levels of their F1's. This suggests that LDN chromosomes 4A, 6A, and 6B may contain genetic factors required for the expression of the PI 277012-derived FHB resistance genes in the F1's. Thereby, durum wheat contains multiple genetic factors on different chromosomes that positively and/or negatively regulate expression of hexaploid wheat-derived FHB resistance genes. This has made FHB resistance introgression from hexaploids into durum a challenging task.