Trends in Plant Science
SpotlightHarnessing Wheat Fhb1 for Fusarium Resistance
Section snippets
Role of Fhb1 Carrier in Breeding Wheat for FHB Resistance
FHB is a fungal disease of cereals, mainly affecting wheat and barley. Since the first epidemics reported on wheat in 1884 in the UK, FHB has become a major disease in most wheat-producing areas. It causes significant reductions in grain yield and quality, costing farmers billions of dollars each year worldwide [1]. Despite intensive searches, no completely resistant germplasm has been identified. Sumai 3, a Chinese wheat cultivar and known Fhb1 carrier, is recognized as the best source of FHB
Molecular Identification of Fhb1
Among several quantitative trait loci for FHB resistance identified in Sumai 3, only Fhb1 consistently shows a major effect on FHB resistance, making it attractive for wheat breeding [1]. The molecular isolation of the gene was hampered by the complexity of FHB resistance and hexaploid nature of the wheat genome. In 2016, Rawat et al. [3] reported that a pore-forming toxin-like (PFT) gene was the candidate for Fhb1 among 13 putative genes (Figure 1) using positional cloning, mutation analysis,
Practical Breeding Strategies
Although the precise genetic basis of Fhb1 remains uncertain, scientists have developed diagnostic molecular markers that are useful for selection in regions where FHB is less prevalent and phenotypic selection is challenging 4, 10. The markers allow breeders to predict the presence of Fhb1 in leading cultivars (Figure 1) and to select the best Fhb1 carrying genotypes. Marker-assisted selection (MAS) underpinned by ‘seed chipping’ and barcoding technologies combined with speed breeding that
Enabling Technologies for Accelerating Genetic Improvement
Using conventional approaches, breeders can now easily transfer Fhb1 into elite wheat, but it may be difficult to remove linkage drag in certain genetic backgrounds resulting from suppressed recombination in the target region [9]. However, transgenesis can overcome this limitation [12]. Since Fhb1 could be a gene complex, transformation of a multigene cassette with His, PFT, and other genes, might confer more stable FHB resistance than the transfer of a single gene. Gene editing is perhaps
Acknowledgments
We are grateful to Dr Robert McIntosh (University of Sydney) for useful suggestions. We acknowledge financial support from the National Key Research and Development Program of China (2016YFD0101802, 2016YFE0108600), Agricultural Science and Technology Innovation Program of CAAS, and the BBSRC cross-institutional strategic program Designing Future Wheat (BB/P016855/1).
References (12)
Wheat resistance to Fusarium head blight
Can. J. Plant Pathol.
(2018)Breeding wheat for resistance to Fusarium head blight in the Global North: China, USA and Canada
Crop J
(2019)Wheat Fhb1 encodes a chimeric lectin with agglutinin domains and a pore-forming toxin-like domain conferring resistance to Fusarium head blight
Nat. Genet.
(2016)Characterization of Fusarium head blight resistance gene Fhb1 and its putative ancestor in Chinese wheat germplasm
Acta Agronomica Sinica
(2018)Molecular characterization and expression of PFT, an FHB resistance gene at the Fhb1 QTL in wheat
Phytopathology
(2018)A deletion mutation in TaHRC confers Fhb1 resistance to Fusarium head blight in wheat
Nat. Genet.
(2019)
Cited by (40)
Update on the state of research to manage Fusarium head blight
2023, Fungal Genetics and BiologyIntegration of meta-QTL discovery with omics: Towards a molecular breeding platform for improving wheat resistance to Fusarium head blight
2021, Crop JournalCitation Excerpt :Searching for these projected marker sequences in the Triticeae Multi-omics Center (http://202.194.139.32/) identified the physical locations (Table S3) and the most likely physical intervals of these smQTL. The distributions of smQTL on chromosomes were illustrated using the R language package Rideogram [31]. A lack of some markers in the genetic maps corresponding to physical maps could result in large physical intervals (>100 Mb in some cases) for the smQTL on the reference sequence map, as a consequence of low marker density, genomic diversity, or chromosome rearrangements in the QTL region.
Can effectoromics and loss-of-susceptibility be exploited for improving Fusarium head blight resistance in wheat?
2021, Crop JournalCitation Excerpt :Lagudah and Krattinger [42] overviewed these two contradictory hypotheses in detail and concluded that further research is needed to clarify the nature of His resistance. However, it is evident through these recent studies that His gene is an important contributor to FHB resistance and its conservation in cereal crops can provide potential new options for improvement of plant resistance to FHB in wheat and other plant species [27,40,43]. As discussed in more detail below, more recently, the gene underlying another QTL (Fhb7) mediating FHB resistance has also been cloned and functionally characterised.
Quantitative trait loci for Fusarium head blight resistance in wheat cultivars Yangmai 158 and Zhengmai 9023
2021, Crop JournalCitation Excerpt :Among all these QTL, only Fhb1 consistently showed the highest level of resistance, explaining up to 50% of the phenotypic variation for type II resistance in different genetic backgrounds and testing environments. Fhb1 has been successfully applied in breeding programs through marker-assisted selection (MAS) worldwide, especially in the USA, Canada, Europe, China, and the International Maize and Wheat Improvement Center (CIMMYT) in Mexico [6,7,15]. To date, many cultivars carrying Fhb1 have been released in the winter wheat regions of the Middle and Lower Valleys of the Yangtze River in China, North Dakota and Minnesota in the USA, and Manitoba in Canada [15].