Life history traits as a function of the gradients in latitude (expressed in °North) and/or population structure (measured as the relative contribution to the first population structure group).

<p>Only significant effects reported in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0061075#pone-0061075-t002" target="_blank">Table 2</a> are shown with the percentage of variance explained associated. (a) Latitude has a significant effect on primary dormancy and flowering time, p<0.05 and p<0.001, respectively. (b) Population structure estimated by the probability to belong to one of the two clusters, has a significant effect on primary and secondary dormancy, p<0.01 and p<0.1, respectively.</p

Major life-history traits and their effect on fitness in annual plant species.

<p>Green triangle: plant, yellow circle: seed, green sector: conditions favourable for growth, grey sector: adverse conditions. Red arrows show the participation of each trait to lifetime fitness, via their effect on survival, resource acquisition or fecundity.</p

Pairs of trait with a latitudinal gradient of co-variation.

<p>Significance was tested with a linear regression model, with latitude as a dependent variable (see methods). p-values associated to the interaction between the traits and the percentage of the latitudinal variation explained by the interaction are shown below and above the diagonal, respectively.</p

Histograms showing natural genetic variation of life history traits using adjusted means.

<p>(a) Primary dormancy (days): measured by number of days required to reach 50% of germination (DSDS50). (b) Secondary dormancy (% of germination decrease per day): measured by the reduction in germination rate of fully after-ripened seed after a 6-week long exposure to 4°C in darkness. (c) Vegetative growth rate (cm²/day): measured by increase of leaf area during one week in the greenhouse. (d) Flowering time (days): number of days until opening of the first flower.</p

Pairwise trait correlation between primary dormancy, flowering time or growth rate change significantly along the latitudinal gradient.

<p>The correlation coefficient <i>r</i> (−1<<i>r</i><1), on the y-axis, was calculated along a sliding latitudinal window with a fixed number of 45 genotypes. The average latitude of each 45-genotype window is given on the x-axis. Red points show local r values with associated <i>p</i><0.05. The change in pairwise trait correlation <i>r</i> with latitude was quantified by the regression coefficient R², and its associated <i>p-value</i> (see methods). With the exception of (d), results hold when sliding windows encompass 25 or 30 genotypes.</p

Pearson correlation coefficients between life history traits (112 genotypes).

<p>Coefficient of correlation (<i>r</i>) and the Bonferroni corrected p-values are shown below and above the diagonal, respectively. Secondary dormancy is not correlated with other traits (not shown).</p

Flowering time as a function of vegetative growth rate.

<p>The 112 European genotypes were divided in three categories: low (blue dots), medium (green dots) and high primary seed dormancy level (red dots).</p

Multi- and uni-variate analyses of life-history variation, p-values associated with the effects of latitude and population structure.

<p>Interaction between the two gradients was not significant (not shown). Because of missing values in secondary dormancy, the multivariate analysis was conducted with and without secondary dormancy. P-values were established with F test based on permutations (see methods). n.s.: not significant, • p<0.1, * p<0.05, ** p<0.01, ***p<0.001. The percentage of variance explained by latitude or population structure gradients is given. df: degrees of freedom for numerator and denominator, respectively.</p

ANOVA table reporting significant effect of the genotype on phenotypic variance for each life-history traits and associating broad-sense heritability <i>H²</i>.

<p>df: degree of freedom. ***p<0.001.</p