The Chromosome-Level Genome of Elaeagnus moorcroftii Wall., an Economically and Ecologically Important Tree Species in Drylands.

Elaeagnus moorcroftii Wall. (Elaeagnaceae) is an important tree species naturally growing in arid Northwest China that has great economic and ecological values in drylands. In this study, we de novo assembled a chromosome-level genome for E. moorcroftii by using PacBio's high-fidelity (HiFi) sequencing and Hi-C-assisted assembly technology. The assembled genome size was 529.56 Mb, of which 94.56% was anchored to 14 pseudochromosomes with a contig N50 up to 28.21 Mb. In total, 29,243 protein-coding genes were annotated, and 98.5% of the Benchmarking Universal Single-Copy Orthologs (BUSCOs) were captured in the genome. Evolutionary genomic analysis showed that E. moorcroftii split with Elaeagnus mollis 9.38 million years ago (Ma), and contrasted evolutionary trajectories of gene family expansion and contraction were observed for these two closely related species. Furthermore, we identified two successive whole genome duplication (WGD) events occurred in the genome of E. moorcroftii, in addition to the ancient gamma hexaploidization event shared by core eudicots. Together, the chromosome-level genome assembly for E. moorcroftii decoded here provides valuable genomic information for the further genetic improvement and molecular breeding of this indigenous species in drylands. [ABSTRACT FROM AUTHOR]