Evolution and diversification of families involved in Cucurbitacin synthesis pathway in Cucurbitales.(a) Cucurbitacin synthesis pathway. (b) Identification of the families involved in Cucurbitacin synthesis pathway in the studied genomes. (c) Phylogenetic tree of FPS gene family of studied genomes. (d) P450 gene amplification model related to gene duplication events in C. moschata. Curved lines within the inner circle, colored grey, link syntenic gene pairs with 1.25<Ks<=1.40. Curved lines in the outer circle, colored red and plum, link gene pairs with 0<Ks<=0.42 and 0.42<Ks<=1.25. P450 genes are displayed in blue patches. (e) The chromosomal distributions of family genes within the cucurbitacin synthesis pathway in studied genomes. The lines between gene pairs represent the paralogous genes. (f) The CDS-UTR structures of a set of FPS orthologous genes between selected genomes.