Fig. 2: Effects of phytohormones on asymbiotic cultures of R. clarus.

All culture media contain both 500 µM Myr-K and 1 g l⁻¹ peptone. a Percentage of secondary spore-forming parent spores relative to germinated parent spores in cultures with different concentrations of GR24 (10, 100, 1000 nM) at 6 WAI. Three bars in each condition are trials 1 to 3, respectively from the left. Different letters above the graph indicate significant differences among treatments in each trial by Fisher’s exact test with Bonferroni correction (p < 0.05). b Numbers of secondary spores in cultures with different concentrations of GR24 (10, 100, 1000 nM) at 6 WAI. Diamonds indicate medians. Statistical significance was calculated using the Wilcoxon rank-sum test with Bonferroni correction (p < 0.05). c, d Time course of germination rate (c) and sporulation rate (d) in media with and without 100 nM GR24. Dashed, solid and dotted lines indicate trials 1–3, respectively. Asterisks above graphs indicate significant differences between treatments in each trial using Fisher’s exact test with Bonferroni correction. ***p < 0.001; *0.01 ≤ p < 0.05; ns, not significant. DAI days after incubation. e Numbers of secondary spores in cultures with different concentrations of methyl jasmonate (MeJA, 0.1, 1, 10 µM) and 100 nM GR24 at 6 WAI. Diamonds indicate medians. Different letters indicate significant differences (Wilcoxon rank-sum test with Bonferroni correction, p < 0.05). f Secondary spores generated from a single parent spore in T (500 µM Myr-K, 1 g l⁻¹ peptone), TG (500 µM Myr-K, 1 g l⁻¹ peptone and 100 nM GR24) and TGM media (500 µM Myr-K, ¹ g l⁻¹ peptone, 100 nM GR24 and 1 µM MeJA) at 8 WAI. Arrowheads indicate parent spores. Large secondary spores were frequently observed in the medium containing both GR24 and MeJA (TGM) than in only GR24 (TG). Many brown spores were observed in TGM and TG media compared to the medium without the phytohormones (T). Bars = 500 µm. g Size distribution of secondary spores produced from 8 parent spores in T, TG and TGM media at 8 WAI. h Percentage of large spores (>70 µm in diameter) in secondary spores produced in T, TG and TGM media at 8 WAI. Different letters indicate significant differences among treatments in each trial using Fisher’s exact test with Bonferroni correction (p < 0.05). p-values are described in Supplementary Data 2.