UV radiation, elevated CO₂ and water stress effect on growth and photosynthetic characteristics in durum wheat

The objective of this research was to investigate the changes in photosynthetic pigments and other physiological and biochemical traits of durum wheat exposed to ultraviolet A, B and C radiation, elevated CO₂ and water stress. The results showed that carotenoids, anthocyanins, flavonoids and proline content increased significantly by decreasing ultraviolet wavelength. Elevated CO₂ increased only height and specific leaf area. Water stress induced a significant increase in carotenoids, anthocyanins, flavonoids, proline and protein content. Interaction of UV-C and water stress in ambient CO₂ increased UV screen pigments and proline content, while under elevated CO₂ these increments were alleviated. Interaction among UV-C radiation, elevated CO₂ and water stress demonstrated a significant decrease in Fv/Fm, chlorophyll, protein, carbohydrates and specific leaf area compared to control. The results of this experiment illustrate that increased UV radiation and water stress induces an increase of screen pigments and elevated CO₂ prevents accumulation of these pigments