|ZHANG, QIJUN - North Dakota State University|
|AXTMAN, JASON - North Dakota State University|
|ZHONG, SHAOBIN - North Dakota State University|
|CAI, XIWEN - North Dakota State University|
|ELIAS, ELIAS - North Dakota Department Of Agriculture|
Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/10/2014
Publication Date: 10/26/2014
Publication URL: http://handle.nal.usda.gov/10113/60110
Citation: Zhang, Q., Axtman, J.E., Faris, J.D., Chao, S., Zhang, Z., Friesen, T.L., Zhong, S., Cai, X., Elias, E.M., Xu, S.S. 2014. Identification and molecular mapping of quantitative trait loci for Fusarium head blight resistance in emmer and durum wheat using a single nucleotide polymorphism-based linkage map. Molecular Breeding. 34:1677-1687.
Interpretive Summary: Fusarium head blight (FHB), commonly known as scab, presently threatens durum wheat production in many durum-growing regions. Because durum wheat lacks high levels of FHB resistance, it is crucial to identify FHB resistance sources for durum wheat breeding programs. We previously identified a cultivated emmer wheat line, PI 41025, to be moderately resistant to FHB. The objective of this study was to identify genes controlling the FHB resistance in PI 41025. In this research, we developed a population consisting of 200 pure lines from a cross between the North Dakota durum wheat cultivar 'Ben' and PI 41025. We then evaluated the population for resistance to FHB in one field nursery and three greenhouse experiments and used the population to develop a genetic map using 2,593 molecular markers. Based on the genetic map and FHB evaluation data, we identified three genes controlling the FHB resistance. One of the genes was derived from Ben and it was mapped to chromosome 2A. The other two genes were derived from PI 41025 and were mapped on 3A and 5A, respectively. The identification of the FHB resistance gene from Ben confirmed the presence of FHB resistance in North Dakota durum cultivars, which have been successfully used for developing new cultivars with improved FHB resistance. This study indicates that combining the FHB resistance genes from emmer wheat with the resistance genes from durum cultivars will be useful for improving FHB resistance in durum wheat.
Technical Abstract: Fusarium head blight (FHB), caused by Fusarium graminearum, threatens durum wheat (Triticum turgidum subsp. durum) production in many durum-growing regions. It is critical to identify useful sources of FHB resistance for durum wheat. A domesticated emmer wheat (T. turgidum subsp. dicoccum) accession, PI 41025, was previously shown to be moderately resistant to FHB. This study aimed to identify quantitative trait loci (QTL) associated with FHB resistance in PI 41025. A population of 200 recombinant inbred lines was developed from a cross between the durum cultivar 'Ben' and PI 41025 and evaluated for reactions to F. graminearum in one field nursery and three greenhouse experiments. The disease severity data and a single nucleotide polymorphism marker-based linkage map from this population were used for QTL analysis. The results showed that a QTL on chromosome 2A from Ben and one QTL each on 3A and 5A from PI 41025 were associated with FHB resistance. The 2A and 3A QTL each explaining 8% of the phenotypic variation were detected only in the greenhouse experiments. The QTL on 5A, which mapped near the domestication gene Q, explained 11% and 35% of phenotypic variation in greenhouse and field evaluations, respectively. The identification of the 2A QTL from Ben confirmed the presence of FHB resistance in North Dakota durum cultivars, which have been successfully used for developing new cultivars with improved FHB tolerance. This study indicates that combining the QTL from related tetraploid species with native durum QTL will be useful for improving FHB resistance in durum.