Fig 2. The degree of paramutation in tetraploids depends on growth temperature in F1.

(A) Experimental setup: Diploid or tetraploid plants with R epialleles were crossed with those containing S or W, and F1 hybrids from reciprocal crossings were grown at 19°C for three weeks before transfer to either 10°C, 19°C, or 24°C until seed maturity. F2 seeds were germinated at 19°C on GM plates containing 20 mg/L hygromycin B and resistance ratios determined after 14 days for tetraploids (B) and diploids (C). Data for reciprocal crosses were combined, as no parent-of-origin difference was observed. Number in parentheses: different F2 populations / technical repetitions for each population. N = number of tested seedlings in each group. Bars represent the mean from two biological with three technical replicates each (B) and one biological with three technical replicates (C), with 100 plated seeds (B) each, or 50 plated seeds (C). Error bars indicate standard deviation. Dashed lines represent the expected segregation for tetraploid (B, 35:1 ≙ 97.2%) and diploid F2 populations (C, 3:1 ≙ 75%). F1 growth temperature is indicated by colour: 10°C (blue), 19°C (green), 24°C (red); light colours: F2 of R/S hybrids, dark colours: F2 of R/W hybrids. Statistical analysis was performed by summed Chi-square goodness-of-fit test with the indicated values.