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Genomics-enabled dissection of sea wheatgrass genome for advancing wheat genetic resources.

Dilkaran Singh·Qijun Zhang·Ghana Challa·Elias M Elias·Steven S Xu·Wanlong Li
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Abstract

Wheat production is challenged by biotic and abiotic stresses. Alien gene transfer is an effective approach to tackle such challenges. We previously showed that sea wheatgrass (SWG; Thinopyrum junceiforme (2n = 2x = 28; J1J2) is an untapped resource possessing resistance to an array of pests and abiotic stress. However, the transfer of these important traits has been hindered by the lack of genomic resources and a clear picture of its genome constitution. Using multi-color genomic in situ hybridization, we distinguished the SWG sub-genomes and corroborated that the J1 sub-genome is closely related to the E genome of Th. elongatum and the J genome of Th. bessarabicum and the J2 sub-genome to the V genome of Dasypyrum villosum. Meanwhile, we developed a draft SWG genome assembly and 127 SWG-specific DNA markers covering the 14 SWG chromosomes. Screening a population of 466 BC2F1 and BC2F2 individuals, derived from backcrosses of wheat-SWG amphiploid to wheat, by the SWG-specific markers led to selection of 72 plants putatively carrying one or two SWG chromosomes. The genome painting analysis of the 72 plants eventually identified a set of 37 wheat-SWG chromosome addition lines covering all the 14 pairs of SWG chromosomes and two compensating Robertsonian translocations (RobTs). While the wheat-SWG chromosome addition lines and RobTs are invaluable genetic resources for wheat improvement via chromosome engineering, our results showed the power of genome-specific markers in combination with genome painting in dissection of a polyploid genome and implicated the origin of a group of important polyploid grasses.

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TriticumGenome, PlantGenomicsGenetic MarkersPoaceaeChromosome MappingChromosomes, PlantPlant BreedingJournal Article

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Dilkaran Singh, Qijun Zhang, Ghana Challa, Elias M Elias, Steven S Xu, Wanlong Li. 2025-09-18. Genomics-enabled dissection of sea wheatgrass genome for advancing wheat genetic resources.. https://doi.org/10.1007/s00122-025-05021-8

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