Chromosome-scale assembly and annotation of the wildwheat relative Aegilops comosa

Wild relatives of wheat are valuable sources for enhancing the genetic diversity of common wheat. Aegilops comosa, an annual diploid species with an MM genome constitution, possesses numerous agronomically valuable traits that can be exploited for wheat improvement. In this study, we report a chromosome-level genome assembly of Ae. comosa accession PI 551049, generated using PacBio high-fidelity (HiFi) reads and high-throughput chromosome conformation capture (Hi-C) data. The assembly spans 4.47 Gb, featuring a contig N50 of 23.59 Mb and a scaffold N50 of 619.05 Mb. A total of 39,063 gene models were annotated through a combination of homoeologous proteins, Iso-Seq, and RNA-Seq data. Comparative genome analysis revealed a terminal intrachromosomal translocation in chromosome 2M of Ae. comosa (and Ae. umbellulata) compared to its homoeologous chromosomes in other diploid wheat species. Phylogenetic analysis showed a close relationship between Ae. comosa and Ae. umbellulata. This newly constructed reference genome of Ae. comosa will serve as an important genomic resource for comparative genomic studies and the cloning of agriculturally important genes.