biologia plantarum

Biologia plantarum 43:227-237, 2000 | DOI: 10.1023/A:1002752210237

Photosynthetic Traits in Wheat Grown under Decreased and Increased CO2 Concentration, and after Transfer to Natural CO2 concentration

P. Ulman¹, J. Čatský², J. Pospíšilová²

¹ Department of Plant Physiology, Faculty of Science, Charles University, Prague 2, Czech Republic

² Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague 6, Czech Republic

Wheat plants were grown from sowing to day 18 in 26-dm³ chambers at three different CO₂ concentrations: 150 (-CO₂), 350 (C, control), 800 (+CO₂) μmol mol^-1. Afterwards, plants of the three variants were grown at the same natural CO₂ concentration. Plant characteristics were measured just before the transfer (0 days after CO₂ treatment, DAT), and at 5 - 8 DAT on the 1^st leaf, and at 12 - 22 DAT on the 4^th leaf. Decreased or increased CO₂ concentrations caused acclimations which persisted after transplantation to natural CO₂ concentration. At 5 - 8 DAT, stomatal density, stomatal conductance (g_s), CO₂ saturated net photosynthetic rate (P_Nsat0), radiation saturated net photosynthetic rate (P_Nsat1), and carboxylation efficiency (τ) were higher in -CO₂ plants and lower in +CO₂ plants than in C plants. As compared with C plants, the photochemical efficiency (α) was lower in -CO₂ and higher in -CO₂ plants, however, chlorophyll (Chl) a, Chl b, Chl a-b and carotenoid contents were lower in both -CO₂ and +CO₂ plants. On the 4^th leaf, which emerged on plant after finishing CO₂ treatments, at 12 - 22 DAT, no differences in stomatal density and g, between treatments were observed. In -CO₂ plants, pigment content and P_Nsat0 were higher, α was lower, and P_Nsat1 and τ were not different from C plants. In contrast, in +CO₂ plants, pigment content, P_Nsat1 and τ were lower, and P_Nsat0 and α were unchanged. Leaf area, dry mass, and tiller development increased in +CO₂ plants and decreased in -CO₂ plants. In the interval between 8 and 22 DAT, lower net assimilation rate in +CO₂ than in -CO₂ plants was observed.

Keywords: carboxylation efficiecy; carotenoids; chlorophyll; growth analysis; net photosynthetic rate; photochemical efficiency; ribulose 1,5-bisphosphate carboxylase, oxygenase; stomatal conductance; Triticum aestivum

Subjects: carbon dioxide, elevated, decreased, photosynthetic traits; carboxylation efficiency, CO₂; carotenoids, CO₂; chlorophyll, CO₂; rowth analysis, CO₂; net photosynthetic rate, CO₂; photochemical efficiency, CO₂ ; photosynthetic rate, CO₂; ribulose 1,5-bisphosphate carboxylase/oxygenase, elevated and decreased CO₂; stomatal conductance, CO₂; Triticum aestivum; wheat, elevated and decreased CO₂, photosynthesis

Published: August 1, 2000  Show citation