Number of galls per gram of dry root infected by <i>M. incognita</i> 14 days post-inoculation on tomato genotypes grown under ambient (390 ppm) and elevated CO<sub>2</sub> (750 ppm).

<p>Each value represents the average (±SE) of four replicates. Different lowercase letters indicate significant differences between CO<sub>2</sub> levels within the same tomato genotype (LSD test: df = 1,16, <i>P </i><0.05); different uppercase letters indicate significant differences among tomato genotypes within CO<sub>2</sub> levels (LSD test: d.f. = 2,24, <i>P </i><0.05).</p>