Correlation network analysis for identifying candidate genes. A) Network of volatiles (upper) and the integrated network of VOCs and genes (bottom). The nodes representing volatiles are colored according to the cluster that they belong to (C1-C13 according to Figure 1), as indicated. Genes are represented as gray nodes. Edges are colored according to their strength. Note that edges have different codifications for each network, which is indicated at the right of each one. Node size indicates its connectivity; the bigger the node, the higher the connectivity measured as node degree (i.e., the number of edges connecting the node). A, A.1, A.2, B, C, and D indicate the main gene sub-clusters. B) Magnification of volatile groups (C1, C2 and C3) showing the interactions with genes in detail. For each gene node, the id is shown. The list of genes belonging to sub-clusters A, A.1, A.2, B, C, and D, as well as some topological parameters, are provided in Additional file 11: Table S7.