Interactive effects of elevated CO2, temperature and water stress on Apera spica-venti L.

Abstract

Effects of elevated CO2, temperature and water availability on Apera spica-venti plants were examined in growth chambers of controlled environment. Plants at the III – IV organogenesis stage were grown in normal (~40%) or drought (<10%) substrate and treated with investigated factor combinations: day/night temperature 21/14°C x CO2 – 350 ppm; 30/23°C x CO2 – 350 ppm; 21/14°C x CO2 – 700 ppm; 30/23°C x CO2 – 700 ppm. After 10 days treatment, leaf area, dry biomass, and the contents of photosynthetic pigments, total phenolic compounds, non-structural carbohydrates and DPPH free-radical scavenging capacity were determined. Growth and physiological traits of A. spica-venti differed in their responses to examined environmental factors and their combinations. Under ambient or elevated CO2 and temperature conditions, substrate moisture shortage resulted in significantly lower dry biomass and leaf area of plants. Influence of investigated factors on chlorophyll a and b content was insignificant, while content of carotenoids was significantly affected by CO2 and temperature interaction (CO2 x T). Total non-structural carbohydrate content in A. spica-venti plants varied according to applied investigated environment factors and their interaction. Independent on temperature, moisture deficiency caused an increment of phenolic compounds at ambient CO2.