Fig. 1

a Different developmental stages of P. mume ‘Xiao lve’ (LE) and P. mume ‘Xiangxuegongfen’ (GF) flowers: (S2) petal baring period; (S3) early flowering period; (S4) full flowering period. b Heatmap analysis of volatile compounds of two P. mume cultivars at three flowering development stages. The colour of the heatmap ranges from dark blue (value, − 2.5) to magenta (value, + 2.5) on a natural logarithmic scale. c Amounts of the six main floral aroma volatile compounds during three different flowering stages of GF and LE. d Score plot of OPLS-DA model of headspace volatiles of P. mume cultivars with the statistical parameters: R²X = 0.999, R²Y = 0.994, Q² = 0.967