Effects of carbon dioxide, temperature and nitrogen treatments on anthocyanin (AC), total phenolic (TP), total flavonoid (TF), DPPH radical scavenging assay (DPPH), ABTS radical scavenging assay (ABTS) and fruit nitrogen content (FNC) of strawberry fruits^a.

a<p>Data are expressed as mean ± SD, n = 12, while *, ** and *** indicate P<0.05, 0.01 and 0.001, respectively. Abbreviations are: DW- dry weight.</p

Total fruit dry weight (a), total fruit number (b) and fruit grades (c, d, e) of strawberry plants cultivated under different conditions (mean ± SD, n = 4).

<p>The berries were graded in three size classes depending on fruit dry weight (FDW; FDW <0.4 g, grade 1; 0.4≤ FDW ≤0.7 g, grade 2; FDW >0.7 g, grade 3). The frequency distribution of grade 1, 2 and 3 is showed in figures c, d and e, respectively. Bars indicate standard deviation, while ^* and ^** indicate significant differences at <i>P</i><0.05 and 0.01, respectively.</p

MGLM analysis of treatment (CO₂, temperature and nitrogen) main effects and their interactions on Fru, Glu, Suc, TSW, SI and DWC of strawberry fruits for plants cultivated at ambient (360 ppm) and elevated (720 ppm) CO₂, high and low temperature, and high and low nitrogen^a.

a<p>Data are expressed as F values, and *, **, ***, **** indicate P<0.05, 0.01, 0.001 and 0.0001, respectively. Abbreviations are: FW- fresh weight; Temp- Temperature; N- Nitrogen; 3-Way- CO₂×Temperature<b>×</b>Nitrogen.</p

Correlations between pooled fruit dry weight and total achene number (TAN, open square), total number of fertilized achenes (TFA, open circle) and total number of aborted achenes (TAA, open triangle) of strawberry fruits for plants grown in different conditions.

<p>Regression lines: solid line, TAN; broken line, TFA; dotted line, TAA. Regression lines: y = a x + b.</p

Correlations between fruit dry weight and total achene number (TAN) of strawberry fruits for plants grown in different conditions (a, b, c and d).

<p>The linear regression: y  =  a x + b.</p

MGLM analysis of treatment (CO₂, temperature and nitrogen) main effects and their interactions on AC, TP, TF, DPPH, ABTS and FNC of strawberry fruits for plants cultivated at ambient (360 ppm) and elevated (720 ppm) CO₂, high and low temperature, and high and low nitrogen^a.

a<p>Data are expressed as F values, and *, **, ***, **** indicate P<0.05, 0.01, 0.001 and 0.0001, respectively. Abbreviations are: FW- fresh weight; Temp- Temperature; N- Nitrogen; 3-Way- CO₂×Temperature<b>×</b>Nitroge.</p

Correlations between fruit dry weight and total achene number (TAN) of strawberry fruits grown in different conditions^a.

a<p>the linear regression: y  =  a x + b, a-slope of linear regression, b-increment of linear regression, r-correlation coefficient.</p>**<p>indicate P<0.01.</p

Strawberry fruits with similar fruit fresh weight (FSW) but different achene abortion rates (AAR).

<p>(a) strawberry fruits with low achene abortion rate; (b) part of the figure a is amplified to indicate the aborted achenes; (c) strawberry fruit with high achene abortion rate; (d) part of the figure c is amplified to indicate the aborted achenes.</p

Treatments performed in controlled growth chambers that were applied to strawberry plants for nearly 6 months^a.

a<p>Values in round brackets indicate the detailed factors designed in the experiment.</p