(A) The genome coverage of high frequency k-mers (count ≥ 2) with lengths from 10 to 50 for seven organisms. (B) The percentage of annotated repeats and de novo detected repeats in the genomes. Total annotated repeats are the union of CRs and SDs. Total de novo detected repeats are calculated by DEL − URL + PRL. (C) The Rmap and Umap with k-mer lengths of 24, 36 and 50 on chr1: 36 036 600–36 042 600. (D) The negative correlation coefficients between Rmap and Umap of 2400 randomly generated sequence regions with a length of 1 Kbp.