Variation of osmolyte content in seedlings from the seven <i>P</i>. <i>abies</i> populations, after 6-week treatments with the indicated NaCl concentrations.

<p>Changes in (a) proline (Pro) and (b) total solube sugars (TSS). Means with SD (n = 3). For each population, different lowercase letters above the bars indicate significant differences among treatments and capital letters indicate significant differences among populations undergoing the same treatment, according to the Tukey test (α = 0.05).