Fig. 2

Two WGDs occurred in the Trochodendrales. a Dot plot showing the DNA sequence alignment of 24 chromosomes in T. sinense. Dots representing the position of paralogous gene-pairs were colored according to the Ks color scale. b Syntenic pattern among genomic regions in A. trichopoda, T. sinense, and N. colorata. Each Amborella region aligns with up to with four regions in Tetracentron that resulted from two WGDs in the early Trochodendrales. Four homologous Tetracentron regions derived from two WGDs align with two distinct N. colorata regions. Examples are highlighted in color in plots b, c, and d. c Syntenic pattern among genomic regions in T. sinense and C. kanehirae. d Syntenic pattern among genomic regions in A. coerulea, N. nucifera, T. sinense, and V. vinifera. e Synonymous substitution rate (Ks) distributions of syntenic blocks for the T. sinense paralogs and orthologs with other species. f Ks distributions of syntenic blocks for paralogs attributed to the α and β WGDs in the Trochodendrales, and orthologs between the two species of Trochodendrales without out-paralogs. g Summary of polyploidy events in the history of eudicots