Fig. 3

Evolution of the R. chinensis ‘CH’ and influence of family gene expansion on the main components of floral aroma. a Phylogenetic tree for ‘CH’ hB and ten other eudicot species contained three outgroups. Gene family expansions are indicated in green, and contractions in black; The estimated divergence time (million years ago, MYA) is indicated at each node; numbers in brackets are the 95% confidence intervals (each center is defined as mean value). The red dot represents a calibration point. b-c Gene Ontology (GO) enrichment analysis of expanded gene families in ‘CH’ (b) and ‘OB’ (c). d Accumulation histogram of four groups of volatile organic compounds of R. chinensis ‘OB’ and ‘CH’