Figure 1.
Overview of the history of ozone exposure and the experimental designs.
Starting from a four-year exposure of a weed community under three ozone selection treatments (0, 90 and 120 ppb) [8]; the subsequent sowing of the soil seed bank samples, coming from each ozone selection treatment replication, in nine plots; the Germination experiments (Seed germination and Seed dormancy experiments) carried out with S. arvensis seeds harvested from the plots; and the Soil seed bank experiment developed with seeds harvested from plants exposed to ambient and added ozone (control and added ozone treatment respectively; maternal ozone treatments).
Figure 2.
Germination (%) of Spergula arvensis seeds for each ozone selection treatment, pre-treatment and incubation temperature.
White, grey and black bars represent germination of seeds (n = 3, ± SE) for 0, 90 and 120 ppb ozone selection treatment, respectively, after 22 days of exposure to pre-treatments: storage at 10 °C and dry condition (control) (A), storage at 5 °C and 75% RH followed by scarification (B), and storage at 25 °C and 75% followed by scarification (C); and then incubated at 10, 15 and 15/25 °C. Above each plot, P-values indicate the effects of Incubation Temperature (Temp.), Ozone selection treatment (Ozone) and the interaction (Temp. xOzone) within each Pre-treatment.
Figure 3.
Germination (%) of Spergula arvensis seeds for each ozone selection treatment
, storage condition and incubation temperature. White, grey and black bars represent germination of seeds (n = 3, ± SE) for 0, 90 and 120 ppb ozone selection treatment, respectively, after being exposed for 22 days to storage conditions combining two temperatures (panels A, B and C: 5 °C, and panels D, E and F: 25 °C) and three relative humidity regimes (panels A and D: 5% RH; panels B and E: 75% RH; panels C and F: 11 days at 75% and 11 days at 5% RH) and incubation temperatures (10, 15 and 15/25 °C). Above each plot, P-values indicate the effects of Incubation Temperature (Temp.), Ozone selection treatment (Ozone) and the interaction (Temp. xOzone) within each storage condition.
Figure 4.
Spergula arvensis seeds viability for ozone selection and maternal ozone treatments related to burial time.
White, grey and black symbols represent viability for seeds of the 0, 90 and 120 ppb ozone selection treatments, respectively, that were grown under ambient ozone concentration (A) or added ozone concentration (B), in relation to days of burial time. Values are means of three samples ± SE.