Extended Data Fig. 2: Chromosomal distribution of homoeologous exchanges (HEs) in the TRILs, homologous recombinations (HRs) in the DRILs, and cytological visualization of crossovers (COs) in all genotypes.
a, Chromosomal distribution of breakpoints of HEs in 202 TRILs and HRs in 218 DRILs, based on whole-genome resequencing data. Each vertical bar represents a breakpoint, with purple indicating HEs and green indicating HRs. Chromosomes are denoted by thick grey lines, and centromeres are marked by red dots. b-d, Cytological visualization and quantification of chiasmata (the cytological manifestation of CO events) during meiosis I (MI) in various genotypes, including diploid parents (Nipponbare and 9311), diploid F1 hybrids (N9-F1 and 9N-F1), autotetraploids (NPB-4X and 9311-4X), segmental allotetraploids (NN99-S1 and 99NN-S1), two TRILs with low-fertility (TN9-16 and TN9-17) and two TRILs with high-fertility (TN9-81 and T9N-14). b-c, representative images of chiasmata in a diploid F1 hybrid (N9-F1) and a TRIL (TN9-16), respectively. The experiment was repeated independently for five times, and all gave the same results. Bars = 10 μm. d, Quantification of the number of chiasmata during MI for the 12 genotypes, with red letters indicating statistically significant differences among the 12 genotypes based on two-sided one-way ANOVA followed by a post-hoc LSD test (P < 0.05). Box plot elements: centre line, median; box limits, lower and upper quartiles; whiskers, minimum and maximum data points. e, A line chart depicting the distribution of breakpoints of HEs (upper) and HRs (lower) aggregated from the 202 TRILs and 218 DRILs, respectively. A 500-Kb sliding window was used for tabulation, and centromere positions are indicated on each chromosome with black dots. NPB is short for Nipponbare. Sample sizes (n) in d are provided in Supplementary Table 25.
