Genome assembly and chromosome anchoring
To obtain a high-quality reference genome for P.tomentosa , we sequenced and assembled the genome of GM15 employing a combination of PacBio, Hi-C and Illumina methods. Its size was estimated to be ~800 Mb by K-mer analysis (Fig. 1e, Table S3). A total of ~54 Gb (~ 70× coverage) PacBio data was assembled to generate a primary draft assembly. To obtain a chromosome-scale assembly, Hi-C reads (430 million reads, 65 Gb, ~ 80×coverage) were used to map the primary draft assembly and construct Hi-C linkage information. Finally, a fine Hi-C interaction map was constructed, and confirmed that potential misjoins had been corrected in the final assembly, and a total of 38 chromosome-scale pseudomolecules were successfully anchored (Fig. 2, Table S4), generating a diploid genome size of 740.2 Mb. The 38 chromosome-scale pseudomolecules covered 92.1% of the estimated 800 Mb genome (Table 1). The sizes of contig N50 and scaffold N50 reached 0.96 Mb and 17.13 Mb, with the longest contig and scaffold being 5.47 Mb, and 46.68 Mb, respectively (Table 1).