Leaf gas exchange, dry matter partitioning, and mineral element concentrations in mango as influenced by elevated atmospheric carbon dioxide and root restriction.
Schaffer B., Whiley A. W., Searle C., Nissen R. J.
Author Affiliation: Tropical Research and Education Center, IFAS, University of Florida, Homestead, FL 32611, USA.
Journal of the American Society for Horticultural Science 122 : 849-855
Abstract : The effects of atmospheric CO2 enrichment and root restriction on net CO2 assimilation (A), dry mass partitioning, and leaf mineral element concentrations in mango cultivars Kensington and Tommy Atkins were investigated. Trees were grown in controlled-environment glasshouse rooms at ambient CO2 concentrations of 350 or 700 µmol/mol. At each CO2 concentration, trees were grown in 8-litre containers, which restricted root growth, or grown aeroponically in 200-litre root mist chambers, which did not restrict root growth. Trees grown in 350 µmol/mol CO2 were more efficient at assimilating CO2 than trees grown in 700 µmol/mol CO2. However, total plant and organ dry mass was generally higher for plants grown at 700 µmol/mol CO2. It is suggested that this was due to increased A as a result of a greater internal partial pressure of CO2 (Ci) in leaves of plants in the CO2 enriched environment. Root restriction reduced A which resulted in reduced organ and plant dry mass. In root-restricted plants, reduced A and dry matter accumulation offset the increases in these variables resulting from atmospheric CO2 enrichment. Atmospheric CO2 enrichment and root restriction did not affect dry mass partitioning. Leaf mineral element concentrations were generally lower for trees grown at 700 µmol/mol, possibly due to a dilution effect from an increased growth rate.