Introduction
The global demand for wheat, one of the most important staple crops, is ever-increasing. To meet this demand, scientists and plant breeders are continually striving for crop improvement strategies that will enhance yield, resistance to pathogens, and adaptability to climatic changes.
A recent breakthrough in wheat breeding reported in BMC Plant Biology on May 6, 2019, showcases the development and characterization of interspecific hybrid lines with genome-wide introgressions from Triticum timopheevii into a hexaploid wheat background. In this seminal work, researchers from The University of Nottingham and the University of Bristol successfully leveraged advanced genomic tools for wheat pre-breeding programs. Let’s delve into the details of this groundbreaking research.
The Research
Published under DOI: 10.1186/s12870-019-1785-z, the article titled “Development and characterisation of interspecific hybrid lines with genome-wide introgressions from Triticum timopheevii in a hexaploid wheat background,” heralds a significant milestone in wheat genetics and improvement.
Triticum timopheevii (2n = 4x = 28; AtAtGG), a wild relative of common wheat, boasts genetic traits that are potentially advantageous for enhancing wheat crops, including resistance to various diseases and stressors. These traits are imperative for augmenting the wheat gene pool, given that the species-specific Ph1 locus in wheat often constrains interspecific hybridization.
The authors, including Devi Urmila U, Grewal Surbhi S, Yang Cai-Yun CY, Hubbart-Edwards Stella S, and several others, have conducted a whole-genome introgression approach using homoeologous recombination in the absence of the Ph1 locus. This method accomplishes the transfer of different chromosome segments from T. timopheevii into Triticum aestivum (hexaploid wheat).
Technical Details
Their research utilized a high-throughput genotyping array equipped with single nucleotide polymorphism (SNP) markers to detect T. timopheevii introgressions in a hexaploid wheat background. This powerful genotyping tool offers a potential boon for marker-assisted selection (MAS) in wheat pre-breeding endeavors.
Through meticulous mapping and chromosome analysis, the team generated SNP markers present on the array, allowing for precise detection and facilitation of the introgression process. These markers serve as signposts for wheat breeders seeking to incorporate beneficial genes from T. timopheevii into commercial wheat varieties.
Results and Implications
The resulting wheat-T. timopheevii hybrid lines have been evaluated genomically and phenotypically, revealing segments of the T. timopheevii genome interspersed within the wheat genome. These introgressions could potentially harbor genes for disease resistance, stress tolerance, and yield improvements.
Moreover, these hybrid lines are an invaluable genetic resource, creating new avenues for wheat improvement that were previously inaccessible due to the reproductive barriers between different wheat species. The removal of such barriers via molecular breeding techniques can catalyze the development of new, high-performing wheat varieties that could revolutionize agriculture.
Conclusion and Future Perspectives
The study outlines the competency of interspecific hybrid lines in wheat improvement and highlights the implications of T. timopheevii introgressions for wheat breeding programs. It also showcases the utility of SNP markers for facilitating the integration of valuable traits from wild relatives into wheat cultivars.
Future work will focus on identifying the specific genes within the T. timopheevii introgressions and elucidating their contributions to wheat phenotype and performance. Additionally, the research opens the door for similar strategies with other wild relatives, expanding the genetic toolkit available for wheat improvement.
Keywords
1. Triticum timopheevii introgression
2. Wheat genetic improvement
3. Hybrid wheat lines
4. SNP markers in wheat breeding
5. Wild relative gene transfer
References
1. Allard RW, Shands RG. Inheritance of resistance to stem rust and powdery mildew in cytogentetically stable spring wheats derived from Triticum timopheevii. Phytopathology. 1954;44:266–274.
2. Badaeva ED, Budashkina EB, Bilinskaya EN, Pukhalskiy VA. Intergenomic chromosome substitutions in wheat interspecific hybrids and their use in the development of a genetic nomenclature of Triticum timopheevii chromosomes. Russ J Genet. 2010;46:769–785. doi: 10.1134/S102279541007001X.
3. Cseh Andras, Yang Caiyun, Hubbart-Edwards Stella, Scholefield Duncan, Ashling Stephen S., Burridge Amanda J., Wilkinson Paul A., King Ian P., King Julie, Grewal Surbhi. Development and validation of an exome-based SNP marker set for identification of the St, Jr and Jvs genomes of Thinopyrym intermedium in a wheat background. Theoretical and Applied Genetics. 2019;132(5):1555–1570. doi: 10.1007/s00122-019-03300-9.
4. King J, Grewal S, Yang C, Hubbart S, Scholefield D, Ashling S, et al. A step change in the transfer of interspecific variation into wheat from Amblyopyrum muticum. Plant Biotech J. 2017;15:217–226. doi: 10.1111/pbi.12606.
5. Winfield Mark O., Allen Alexandra M., Burridge Amanda J., Barker Gary L. A., Benbow Harriet R., Wilkinson Paul A., Coghill Jane, Waterfall Christy, Davassi Alessandro, Scopes Geoff, Pirani Ali, Webster Teresa, Brew Fiona, Bloor Claire, King Julie, West Claire, Griffiths Simon, King Ian, Bentley Alison R., Edwards Keith J. High-density SNP genotyping array for hexaploid wheat and its secondary and tertiary gene pool. Plant Biotechnology Journal. 2015;14(5):1195–1206. doi: 10.1111/pbi.12485.