Fig. 5

Functional annotation of genes responsible for variation in quercetin 3-O-glucoside content and SR weight per plant. A Clustering of four groups (G1–G4) of cultivated cassava based on the metabolite profiles in SR. B Differences in SR weight per plant among four groups (G1–G4) of cultivated cassava shown in A. Different letters indicate significant differences at P < 0.05 based on Duncan’s multiple range tests. C Relative contents of four flavones among seven developmental stages (S1–S7) of storage root in cassava cultivar SC205. D-G Relative contents of four flavones negatively correlated with SR weight per plant among four cassava groups (G1–G4) shown in A. H Manhattan plot displaying the GWAS results for quercetin 3-O-glucoside contents. I Manhattan plot displaying the GWAS results for SR weight per plant. J Gene model of Sc02g015220 (MeFLS1) located 65.6 kb from the lead SNP 2:12844688, which is indicated by a vertical arrow. The causative SNP 2:12776464, which located in the 3’UTR of MeFLS1, is indicated by a red star. K Phylogenetic tree of MeFLS1 and FLS genes from other species. Bootstrap values are indicated at each node. L Pearson correlation between the expression of MeFLS1 and the content of quercetin 3-O-glucoside in SR of 22 cassava cultivars. M Differences in expression of MeFLS1 in SR attributable to the causative SNP 2:12776464. N Boxplot displaying the relative content of quercetin 3-O-glucoside attributable to the causative SNP 2:12776464. O Boxplot displaying SR weight per plant attributable to the causative SNP 2:12776464. P Comparison of activities between G-containing and T-containing promoter regions (1000 bp upstream of ATG) in dual luciferase assay. Each sample contains seven biological replicates. Q Differences in quercetin 3-O-glucoside contents between wild and cultivated cassava. The significance in (M-Q) was determined by the Student's t-test. R Nucleotide diversity (Pi) between the wild (n = 19) and cultivated (n = 299) cassava accessions around the MeFLS1 region in 80-kb sliding windows with 10-kb steps. S Allele frequencies of the causative SNP 2:12776464 between wild and cultivated cassava accessions