Single and combined impact of elevated tropospheric oone and simulated warmed climate conditions on Summer Rape (Brassica Napus L.) and Wild Mustard (Sinapis Arvensis L.)

Abstract

A future climate with increased air temperature and concentrations of atmospheric carbon dioxide (CO2) and tropospheric ozone (O3) will likely alter crops productivity, as well as prosperity of weeds. In this study there were examined the impact of simulated warmed climate conditions (25/18 ºC and 800 ppm vs. 21/14 ºC and 400 ppm, air temperature day/night and CO2) and elevated concentration of tropospheric ozone (90 ppb vs. 0 ppb) on summer rape (Brassica napus L.) and wild mustard (Sinapis arvensis L.) and if simulated warmed climate conditions interacted with elevated concentration of tropospheric ozone in combined treatment. The physiological response and growth parameters of summer rape and wild mustard were in different manner. Summer rape grown under simulated warmed climate conditions showed significantly increased photosynthetic rate, leaf area, shoot and root dry weight, while in wild mustard all these parameters were not changed significantly. Under ambient climate conditions elevated O3 decreased gas exchange parameters and leaf area in both species with more significant changes in wild mustard and significantly decreased their shoot and root dry weight. In contrast, no changes were observed in shoot and root dry weight of summer rape. Despite the fact that photosynthetic rate and growth of wild mustard were not stimulated significantly under simulated warmed climate conditions, the negative impact of elevated concentration of tropospheric ozone was mitigated by simulated warmed climate conditions for both species and, what is more interestingly, for wild mustard even more with significant increase in their shoot dry weight under combined impact of elevated tropospheric ozone and simulated warmed climate conditions.[...]