INCREASED LEAF STOMATAL CONDUCTANCE AT VERY HIGH CARBON DIOXIDE CONCENTRATIONS

in HortScience
View More View Less
  • 1 The Bionetics Corp. (clm, ncy) and NASA Biomedical Operations and Research Office (rmw), Kennedy Space Center, FL 32899

Leaf stomatal conductance was monitored with a steady-state porometer throughout growth and development of soybean and potato plants grown at 500, 1000, 5000, and 10,000 (potato only) μmol mol-1 carbon dioxide (CO2). All plants were grown hydroponically with a 12-hr photoperiod and 300 μmol m-2 s-1 PPF. As expected, conductance at 1000 was < 500 μmol mol-1 for both species, but conductance at 5000 and 10,000 μmol mol-1 was ≥ that at 500 μmol mol-1. Subsequent short-term (24-hr) tests with potato and wheat plants grown at 1000 μmol mol-1 showed that raising CO2 to approx. 10,000 μmol mol-1 or lowering CO2 to 400 μmol mol-1 increased conductance compared to 1000 μmol mol-1 for potato, while only lowering CO2 to 400 μmol mol-1 increased conductance for wheat. Furthermore, raising the CO2 to 10,000 μmol mol-1 increased dark-period conductance in comparison to 1000 μmol mol-1 for potato, while dark-period conductance for wheat leaves was low regardless of the CO2 concentration. Results suggest that very high CO2 levels (e.g. 5000 to 10,000 μmol mol-1) may substantially increase water use of certain crops.

If the inline PDF is not rendering correctly, you can download the PDF file here.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 90 8 0
PDF Downloads 43 16 3