Fig.1 Soft threshold determination of gene co-expression network The vertical coordinate of Fig.B represents the mean connectivity corresponding to each soft threshold; C and D.The detection of topological network compliance at a power value of 14.

Fig.2 SEM of seed pericarp and changes in pericarp thickness of M08 and M03 at three different periods A-C.SEM results of 15,19 and 23 days after M03 pollination;D-F.SEM results of 15,19 and 23 days after M08 pollination;G.The change of pericarp thickness of M03 and M08.The letters in the column are Duncan’s multiple comparison results,different letters indicate significant difference between materials at the level of P<0.05.

Fig.3 Number of DEGs in different datasets and venn diagram

Fig.4 GO and KEGG enrichment analysis of DEGs A.Three different color histograms respectively represent the three categories of GO enrichment;B.The vertical axis represents the enriched KEGG pathway,and the horizontal axis represents the ratio of enriched genes,the point size represents the number of genes enriched in the path,and the color represents the P value corrected by multiple tests.The same as Fig.7.

Fig.5 Gene co-expression module and the number of genes contained in each module A. A gene cluster tree,each cluster tree corresponds to a gene module,and with the same clustering level are represented by the same color;B.The 18 modules clustered and the number of genes contained in each module.

Fig.6 Phenotype-module correlation heatmap and number of genes shared by significant modules and DEGs A.The heat map of correlation coefficient between each module and peel thickness,and the red box is the specific module; B.The number of genes shared by specific modules and DEGs.

Fig.7 KEGG enrichment analysis of significant module

Fig.8 Gene co-expression network and hub genes of significant modules A-D are the gene networks of Turquoise module,Yellow module,Pink module and Magenta module respectively; the large red dot is the hub gene,and the gray rectangle is the annotation of phenotype related genes in the module.

Fig.9 qRT-PCR validation of hub genes The bar graph represents the qRT-PCR results,and the broken line graph represents the RNA-seq results;in the abscissa,3 and 8 represent M03 and M08 respectively,and a,b and c represent 15,19 and 23 day after pollination respectively.The letters in the column are Duncan’s multiple comparison results,different letters indicate that there is a significant difference between materials at the level of P<0.05.