Figure 3.

The allopolyploid A. suecica produces more starch than its progenitor species under high light levels. A, Plants were grown in the greenhouse under light intensities of ∼200 µmol m⁻² s⁻¹ light until harvest and starch quantification. Statistical significance was calculated to compare the allopolyploid to each progenitor species using Welch two-sample t tests (At-As: t = −0.1551, df = 8.37, and P = 0.878; Aa-As: t = 1.237, df = 14.03, and P = 0.237; n: At = 15, Aa = 9, and As = 12). Differences between progenitor species were not statistically analyzed. B, Plants were grown in the greenhouse under light intensities of ∼200 µmol m⁻² s⁻¹ light until the night before harvest. During the last night, plants were kept in complete darkness for ∼15 h and then exposed for 6 h to light intensities of ∼750 µmol m⁻² s⁻¹ before harvesting leaves and extracting and quantifying total starch concentrations. Statistical significance was calculated to compare the allopolyploid to each progenitor species using Welch two-sample t tests (At-As: t = −5.31, df = 8.37, and P = 0.0006; Aa-As: t = −4.69, df = 8.5, and P = 0.001; n: At = 6, Aa = 6, and As = 5). Differences between progenitor species were not statistically analyzed. Box plots show data range, including median (bold line), the 25th and 75th percentiles (lower and upper end of box), and 5th or 95th percentiles of data distribution (lower and upper whiskers). Outliers are indicated with circles. Asterisks indicate statistical significance between samples. At, A. thaliana; Aa, A. arenosa; As, A. suecica.