Fig. 2

Evolutionary history of LTR-Rs and duplications of protein-coding genes in the pepper genomes. a Distribution of LTR-R insertions. The graphs in the left and right panels depict the predicted insertion dates of LTR-R superfamilies (gypsy, copia) and two specific families (del, athila). The x- and y-axes indicate the insertion times and the number of insertions at each time, respectively. b Time-scaled gene duplication history (left) and top ten repertoires of massive gene duplication (right). The x- and y-axes of the graph in the left panel indicate the approximate duplication time (MYA) and the number of gene duplications, respectively. The x- and y-axes of the histogram in the right panel represent the number of genes and domain description, respectively