Fig. 1: Significant association of DRG9 with relative green-projected area ratio (GPAR_R), a drought resistance indicator.

a DRG9-based association mapping and pairwise LD analysis. Dots represent SNPs. The lead SNP is highlighted by diamond. The SNPs showing strong LD with the lead SNP are connected to the pairwise LD diagram with solid lines and highlighted with black lines. P values are calculated based on mixed linear model and the red dashed line indicates the significance threshold (3.09 × 10⁻³), which is determined by the Bonferroni test. b Major haplotypes of DRG9. The numbers 0823, 0824, 1066, and 2981 indicate the positions of the significantly associated SNP in DRG9. c SNPs (SNP 1066 A > G, SNP 0823 T > G, SNP 0824 T > G) in the coding sequence causing two amino acid substitutions (Asn to Ser and Phe to Gly, respectively). d Comparison of GPAR_R between the Hap1 and Hap2 using the two-tailed t-tests (n = 130 and 373 rice accessions). e Comparison of DRG9 expression between the drought-resistant (DR) Hap1 and drought-sensitive (DS) Hap2 haplotypes. Gene expression levels were determined among 71 DR accessions and 222 DS accessions under normal condition and drought stress. For the box plots in d, e, the center line indicates the median, the edges of the box represent the first and third quartiles, the whiskers extend to 1.5 times interquartile range from the box edges, and dots denote outliers. Statistical significance was determined using the two-tailed t-test. Source data are provided as a Source Data file.