3.3 Chromosome-level assembly of Hi-C data
A total of 0.54 Gb assembled scaffold sequence was correctly divided into sixteen groups corresponding to the sixteen Chinese walnut chromosomes (Figure 2c; Figure S1). A total of 397 contigs and 189 scaffolds were generated by Hi-C sequencing data; the N50 size of contigs was 6.49 Mb and the N50 size of scaffolds was 36.1 Mb, respectively (Table 1). Hi-C sequence (543 Mb) was mapped and anchored ( 99 % ;543 Mb/548 Mb) to the assembled 16 chromosomes of the Chinese walnut genome (Table 1).Chromosome numbering for J. cathayensis was based on homology to the numbering of J. regia chromosomes (Zhang et al., 2020) (Table S7). The lengths of the 16 assembled chromosomes of Chinese walnut ranged from 19,675,958 bp to 55,052,647 bp with mean length is 33,963,507 bp, while chromosomes of Persian walnut ranged from 20,184,194 bp to 518,39,233 bp with mean length is 33,799,624 bp (Table S7).