Fig. 5: Meiotic chromosome pairing behaviour, pollen fertility, and pollen ploidy of representative TRILs, and the relevant controls.
The autotetraploids are NPB-4X and 9311-4X, and the reciprocal S1 segmental allotetraploids are NN99 and 99NN. a,b, Representative images of chromosome pairing behaviour at metaphase/diakinesis of meiosis I (MI) in PMCs from 5 independent inspections, n = 3 for each genotype. Different chromosomal pairing configurations (adjacent quadrivalent, alternate quadrivalent, bivalent, chain and ambiguous) are indicated. Scale bars, 10 μm. c, Tabulated number (mean ± s.d.) and percent of the various types of pairing configuration at metaphase/diakinesis are from PMCs of at least 3 euploid plants for each of the 8 kinds of tetraploids. Different red letters represent statistical differences in multiple comparisons across the 8 tetraploid types by two-sided one-way ANOVA followed by a post-hoc LSD test (P < 0.05, in total quadrivalents and bivalents columns) and two-sided Chi-square test (FDR-adjusted P < 0.05, in chain, adjacent, alternate and ambiguous columns). d–o, Microscopy images of iodine-potassium-iodide-stained pollens from the diploid parents (Nipponbare and 9311), the reciprocal diploid hybrids (N9-F1 and 9N-F1), the parental autotetraploids (NPB-4X and 9311-4X), the first-generation reciprocal segmental allotetraploids (NN99-S1 and 99NN-S1), two low-fertility TRILs (TN9-16 and TN9-17), and two high-fertility TRILs (TN9-81 and T9N-14), respectively. Scale bars, 100 μm. The snapshot images are representative of each genotype based on 5 independent inspections, n = 3. p, Quantified proportions of fertile pollens across the 12 genotypes. Different red letters indicate statistically significant differences among the 12 genotypes based on two-sided one-way ANOVA followed by a post-hoc LSD test (P < 0.05), and sample sizes are provided in Supplementary Table 25. In boxplots: centre line, median; box limits, lower and upper quartiles; whiskers, minimum and maximum data points. q,r, DAPI-stained images of mature pollens from diploid F1 hybrid (N9-F1) (q) and TRIL (TN9-16) (r). Scale bars, 10 μm. Representative figure from 5 independent inspections, n = 3 for each genotype. s, A combined peak diagram of the DNA content of pollen nuclei from both diploid (red) and tetraploid (blue) rice genotypes (n = 3) based on flow cytometry data. Representative figure from 3 independent experiments, n = 3 for each genotype.
