Fig. 2

Gene duplication and environmental selection pressure analysis. a One-to-one orthologous NBS-LRR genes between V. fordii and V. montana. The green lines indicate orthologous NBS-LRR genes in a similar homologous chromosomal location between V. fordii and V. montana. b Gene duplication analysis of V. montana. The orange lines indicate NBS-LRR duplication genes in V. montana. c Scatter plots of the Ka/Ks ratios of orthologous NBS-LRR gene pairs between V. fordii and V. montana. The X-axes and Y-axes indicate the Ka and Ka/Ks ratio for each pair, respectively. d Frequency distribution histogram of Ka/Ks of orthologous NBS-LRR gene pairs between V. fordii and V. montana