Abstract Yellowhorn (Xanthoceras sorbifolium) is widely used in northern China for landscaping, desertification control, and oil production.
Abstract Yellowhorn (Xanthoceras sorbifolium) is widely used in northern China for landscaping, desertification control, and oil production. However, the lack of high-quality genomes has hindered breeding and evolutionary studies. Here, we present the first haplotype-resolved, telomere-to-telomere (T2T) yellowhorn genomes of PBN-43 (white single-flowered) and PBN-126 (white double-flowered) using PacBio HiFi and Hi-C data. These assemblies range from 464.34 Mb to 468.97 Mb and include all centromeres and telomeres. Genome annotation revealed that an average of 67.99% (317.09 Mb) of yellowhorn genomic regions consist of repetitive elements across all haplotypes. The number of protein-coding genes ranges from 35,039 to 35,174 among assemblies, representing an average 50.16% increase over the first published yellowhorn genome. Additionally, 93.90% of the annotated genes have functional annotations. We found yellowhorn experienced an LTR-RT burst during the last 0.45–0.48 Mya. These data provide a resource for investigating genomic variations, phylogenetic relationships, duplication modes, and the distribution of nucleotide-binding leucine-rich repeat (NLR) genes, and support further research into yellowhorn breeding.