Individual and interactive effects of elevated carbon dioxide and ozone on tropical wheat (Triticum aestivum L.) cultivars with special emphasis on ROS generation and activation of antioxidant defence system

摘要

The effects of elevated COsub2/sub and Osub3/sub, singly and in combination were investigated on various physiological, biochemical and yield parameters of two locally grown wheat (i style="mso-bidi-font-style:normal"Triticum aestivum/i L.) cultivars (HUW-37 and K-9107) in open top chambers (OTCs). Elevated COsub2/sub stimulated photosynthetic rate (Ps) and Fsubv/sub/Fsubm/sub ratio and reduced the stomatal conductance (gsubs/sub). Reactive oxygen species, lipid peroxidation, anti-oxidative enzymes, ascorbic acid and total phenolics were higher, whereas Ps, gsubs/sub, Fsubv/sub/Fsubm/sub, protein and photosynthetic pigments were reduced in elevated Osub3/sub exposure, as compared to their controls. Under elevated COsub2 /sub+ Osub3/sub, elevated levels of COsub2/sub modified the plant performance against Osub3/sub in both the cultivars. Elevated COsub2/sub caused significant increase in economic yield. Exposure to elevated Osub3 /subcaused significant reduction in yield and the effect was cultivar-specific. The study concluded that elevated COsub2/sub ameliorated the negative impact of elevated Osub3/sub and cultivar HUW-37 was more sensitive to elevated Osub3/sub than K-9107." xml:lang="en_US