The chromosome-scale assembly of the willow genome provides insight into Salicaceae genome evolution

Suyun Wei; Yonghua Yang; Tongming Yin

doi:10.1038/s41438-020-0268-6

The chromosome-scale assembly of the willow genome provides insight into Salicaceae genome evolution

Hortic Res. 2020 Apr 1:7:45. doi: 10.1038/s41438-020-0268-6. eCollection 2020.

Authors

Suyun Wei^{1

2}, Yonghua Yang³, Tongming Yin¹

Affiliations

¹ 1Key Laboratory for Tree Breeding and Germplasm Improvement, Southern Modern Forestry Collaborative Innovation Center, College of Forestry, Nanjing Forestry University, Nanjing, 210037 China.
² 2College of Information Science and Technology, Nanjing Forestry University, Nanjing, 210037 China.
³ 3College of Life Sciences, Nanjing University, Nanjing, 210093 China.

Abstract

Salix suchowensis is an early-flowering shrub willow that provides a desirable system for studies on the basic biology of woody plants. The current reference genome of S. suchowensis was assembled with 454 sequencing reads. Here, we report a chromosome-scale assembly of S. suchowensis generated by combining PacBio sequencing with Hi-C technologies. The obtained genome assemblies covered a total length of 356 Mb. The contig N50 of these assemblies was 263,908 bp, which was ~65-fold higher than that reported previously. The contiguity and completeness of the genome were significantly improved. By applying Hi-C data, 339.67 Mb (95.29%) of the assembled sequences were allocated to the 19 chromosomes of haploid willow. With the chromosome-scale assembly, we revealed a series of major chromosomal fissions and fusions that explain the genome divergence between the sister genera of Salix and Populus. The more complete and accurate willow reference genome obtained in this study provides a fundamental resource for studying many genetic and genomic characteristics of woody plants.

Keywords: DNA sequencing; Next-generation sequencing.