Fig. 4

Heatmap with two-dimensional hierarchical dendrograms of the volatiles in the hybrid population (Pop AC). Each column in the heat map represents a volatile, and each row represents a genotype. The upper dendrogram corresponds to the volatiles, after which the clusters are indicated by C1–C10. The left dendrogram corresponds to the individuals, indicating the clusters by S1–S14. For heatmap visualisation, the concentrations of each compound were normalised based on the average concentration among all individuals for 2 years. Higher concentrations for each compound are presented in red, whereas lower concentrations are presented in blue, as shown on the scale on the right. Bound volatiles are indicated by (B), whereas the free volatiles are indicated by (F)