Figure 2 Comparative Genomic Analysis.
a The phylogenetic tree based on the Bayesian inference method was constructed using 465 single-copy homologous genes from 24 species. The basal angiosperm Amborella trichopoda was selected as outgroup. A red branche represent S. rosmarinus , which diverged from S. miltiorrhiza and S. splendens at ca. 21.47 Mya. Orange ellipse represent the reported WGT event, and green and red ellipses represent reported WGD events and the identified WGD event in this study, respectively. b Synonymous substitution rate (Ks ) distributions of syntenic blocks for the paralogs and orthologs of S. rosmarinus, S. miltiorrhiza and S. splendens. The gray box indicates the unique WGD event inĀ S. rosmarinus . c The karyotype evolution from seven chromosomes of a eudicot ancestor to seven species (Vitis vinfera ,Arabidopsis thaliana , Scutellaria baicalensis ,Tectona grandis , S. miltiorrhiza , S. splendens andS. rosmarinus ). Genome polyploidy events are indicated by red circles, and the lower columns show the retention of ancestral genes in the chromosomes of seven species. The yellow branch represents S. miltiorrhiza , and the green branch represents S. rosmarinus .d The karyotype evolution of S. rosmarinus, S. miltiorrhiza and S. splendens from their recent common ancestor to the present. The karyotype evolution speculation map of S. rosmarinus in the green dashed box, S. miltiorrhiza in the yellow dashed box and S. splendens in the blue dashed box. D represents the occurrence of whole genome duplicated event.