Genome survey
We used the k-mer method to survey the genome features of the PFM. The k-mer count histogram was obtained from Illumina paired-end sequencing data using Jellyfish v2.99 (Marçais & Kingsford, 2011) with 17, 21, 25 and 35 mers. Genome size, heterozygosity and rate of duplication were estimated by GenomeScope v1.0 (Vurture et al., 2017).