Chromosome-scale genome assembly of bread wheat’s wild relative Triticum timopheevii

Authors: GREWAL, SURBHI - University Of Nottingham; YANG, CAI-YUN - University Of Nottingham; SCHOLEFIELD, DUNCAN - University Of Nottingham; ASHLING, STEPHAN - University Of Nottingham; GHOSH, SREYA - Earlham Institute; SWARBRECK, DAVID - Earlham Institute; COLLINS, JOANNA - Wellcome Trust Sanger Institute; YAO, ERIC - University Of California Berkeley; Sen, Taner; WILSON, MICHAEL - University Of Nottingham; YANT, LEVI - University Of Nottingham; KING, IAN - University Of Nottingham; KING, JULIE - University Of Nottingham

Submitted to: Scientific Data
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/15/2024
Publication Date: 4/23/2024
Citation: Grewal, S., Yang, C., Scholefield, D., Ashling, S., Ghosh, S., Swarbreck, D., Collins, J., Yao, E., Sen, T.Z., Wilson, M., Yant, L., King, I., King, J. 2024. Chromosome-scale genome assembly of bread wheat’s wild relative Triticum timopheevii. Scientific Data. 11. Article 420. https://doi.org/10.1038/s41597-024-03260-w.
DOI: https://doi.org/10.1038/s41597-024-03260-w

Interpretive Summary: Bread wheat is one of the most important food crops with an urgent need for increase in its production to feed the growing world. Wheat’s wild relative species Triticum timopheevii provide a hugely untapped reservoir of genetic diversity for wheat improvement, which has been harnessed in many wheat pre-breeding programmes over the last few decades. In this study, we report the generation of a chromosome-scale reference genome assembly of T. timopheevii. Comparative genome analysis confirmed previously known chromosomal translocations and indicated new chromosome rearrangements. In summary, the T. timopheevii genome assembly provides a valuable resource for genome-informed discovery and cloning of agronomically important genes for future food security.

Technical Abstract: Wheat (Triticum aestivum) is one of the most important food crops with an urgent need for increase in its production to feed the growing world. Wheat’s wild relative species provide a hugely untapped reservoir of genetic diversity for wheat improvement. Triticum timopheevii (2n = 4x = 28) is a tetraploid wheat wild relative species containing the At and G genomes that has been exploited in many wheat pre-breeding programmes over the last few decades. In this study, we report the generation of a chromosome-scale reference genome assembly of T. timopheevii accession PI 94760 based on PacBio HiFi reads and chromosome conformation capture (Hi-C). The assembly comprised a total size of 9.35 Gb, featuring a contig N50 of 42.4 Mb, and 166,325 predicted gene models. Comparative genome analysis confirmed previously known chromosomal translocations and indicated new chromosome rearrangements. Analysis of the genomic distribution of DNA methylation showed that the G genome had on average more methylated bases than the At genome. The G genome was also more closely related to the S genome of Aegilops speltoides than to the B genome of hexaploid or tetraploid wheat. In summary, the T. timopheevii genome assembly provides a valuable resource for genome-informed discovery and cloning of agronomically important genes for future food security.