Chromosome-level genome of Osmia excavata (Hymenoptera: Megachilidae) provides insights into low-temperature tolerance of Osmia pollinator.

The solitary bee Osmia excavata (Hymenoptera: Megachilidae) is a key pollinator managed on a large scale. It has been widely used for commercial pollination of fruit trees, vegetables, and other crops with high efficiency in increasing the crop seeding rate, yield, and seed quality in Northern hemisphere. Here, a high-quality chromosome-level genome of O. excavata was generated using PacBio sequencing along with Hi-C technology. The genome size was 207.02 Mb, of which 90.25% of assembled sequences were anchored to 16 chromosomes with a contig N50 of 9,485 kb. Approximately 186.83 Mb, accounting for 27.93% of the genome, was identified as repeat sequences. The genome comprises 12,259 protein-coding genes, 96.24% of which were functionally annotated. Comparative genomics analysis suggested that the common ancestor of O. excavata and Osmia bicornis (Hymenoptera: Megachilidae) lived 8.54 million years ago. Furthermore, cytochrome P450 family might be involved in the responses of O. excavata to low-temperature stress. Taken together, the chromosome-level genome assembly of O. excavata provides in-depth knowledge and will be a helpful resource for the pollination biology research.