Figures (6)  Tables (2)
    • Figure 1. 

      Relationships between leaf traits. Scatter plots and histograms display the distribution of each trait. The red line overlaid on each histogram represents the density distribution. '*', '**' and '***' denote significant correlations at the 0.05, 0.01, and 0.001 levels, respectively. Red and blue asterisks represent positive and negative correlations, respectively.

    • Figure 2. 

      Principal component analysis (PCA) and hierarchical clustering analysis based on leaf phenotype data. (a) The PCA plot showing the first and second principal components of P. cathayana genotypes, represented by color-coded points, and the relative importance of explanatory variables is indicated by vectors. (b) Clustering of P. cathayana populations into four categories based on leaf traits. (c) Comparison of four leaf shape categories[28].

    • Figure 3. 

      Selective sweep analysis visual line chart and frequency histogram. Genetic differentiation coefficient (Fst) and nucleotide diversity (π) were calculated by the sliding window method with a window size of 10 kb and a step size of 1 kb; XP-CLR has the same window size as Fst and π. The plots (a), (b) and (c) respectively represent the line graph and frequency histogram of Fst, π, and XP-CLR. In the line plot, the blue line and red line represent the top 5% and top 1% thresholds, respectively, and correspond to the blue and red shaded areas in the frequency histogram. The interval that passes the top 5% threshold lines in three methods is considered as the final candidate region for selective sweep.

    • Figure 4. 

      Functional enrichment analysis of selective sweep candidate genes. (a) GO enrichment analysis of candidate genes, where the size of the points represents the number of genes, and the color of the points indicates significance level. BP, CC, MF respectively represent biological process, cellular component, and molecular function. (b) KEGG enrichment analysis of candidate genes, where the size of the points represents the number of genes, and the color of the points indicates significance level.

    • Figure 5. 

      GEMMA multi-trait GWAS Manhattan plots and significant locus analysis. The plots (a), (b), (c), (d), and (e) correspond to the manhattan plots of LA_LP_LL_LW, LA_PL_SPAD, LI_LW_LL, LMF_LA_LP and RPL_LI_LMF, respectively. For ease of comparison, we have included the single-trait GWAS Manhattan plots of the traits in the figures. Each dot on the plot represents a SNP, with dot colors indicate single-trait or multi-trait associations. p_value were transformed into −log10(p_value). SNPs above green lines passed bonferroni correction test (p ≤ 8.51 × 10−8). The red circle represents the detected loci in multiple trait combinations. (f) Analysis of genetic differentiation (Fst) and nucleotide diversity (π) near SNP 7__12437614. (g) Comparison of leaf phenotypes corresponding to three haplotypes at SNP 7__12437614, represented by mean values in a bar graph with standard deviation as the error. (h) Analysis of genetic differentiation (Fst) and nucleotide diversity (π) near SNP 18__14798104. (i) Comparison of leaf phenotypes between two haplotypes at SNP 18__14798104, represented by mean values in a bar graph with standard deviation as the error.

    • Figure 6. 

      Candidate gene network visualization. Circles represent candidate genes, and the size of the circles indicates the number of associated traits. The color of the circles corresponds to different types of candidate genes. Lines represent the traits associated with genes and whether they are candidate genes for selective sweep.

    • TraitAbbreviationMeanSDMinMaxCVaVgbVecH2d
      Leaf areaLA118.27237.23521.034219.5870.311,143.7214685.74880.6252
      Leaf perimeterLP51.9869.64223.01783.7620.1987.911166.33780.5699
      Leaf lengthLL16.3442.5117.73322.3270.155.43032.70190.6678
      Leaf widthLW10.2422.0723.48315.6330.203.92902.91500.5741
      Petiole lengthPL3.2051.0470.7865.5130.330.98760.38140.7214
      Relative petiole lengthRPL0.1970.0610.0660.3760.310.06710.02560.7234
      Leaf indexLI1.6450.2721.0422.5200.170.00030.00050.3791
      Leaf margin factorLMF0.1730.0190.1230.2320.110.00330.00120.7375
      Leaf chlorophyllSPAD41.9894.58730.99357.2330.117.07704.96800.5875
      a Coefficient of variation; b genetic variance; c residual variance; d heritability,

      Table 1. 

      Results of statistical analysis of leaf traits.

    • rsaTraitp_valuePVEbGeneFunctional annotation
      19__8697977LW5.36E-083.15Pca19G006210Reverse transcriptase
      Pca19G006220RNase H-like domain found in reverse transcriptase
      10__3487289LL6.77E-082.97Pca10G001830Protein tyrosine and serine/threonine kinase
      Pca10G001840D-mannose binding lectin
      9__9068032PL1.04E-083.34Pca09G008070WD domain, G-beta repeat
      Pca09G008080Clp protease
      Pca09G008090C2H2-type zinc finger
      8__15332723SPAD2.24E-083.24Pca08G0188005' nucleotidase family
      1__26393650RPL2.10E-081.98Pca01G022670NA
      Pca01G022680Protein of unknown function (DUF1117)
      9__9068032RPL5.28E-082.20Pca09G008070WD domain, G-beta repeat
      Pca09G008080Clp protease
      Pca09G008090C2H2-type zinc finger
      18__14798104LMF4.57E-091.08Pca18G011690Cytochrome P450
      Pca18G011700Protein tyrosine and serine/threonine kinase
      Pca18G011710Cytochrome P450
      NA, not available. a The name of the SNP. b The proportion of phenotype variance explained by SNP.

      Table 2. 

      Statistical information of significant SNPs in single-trait GWAS.