Response of Two Wheat Cultivars to CO2 Enrichment under Subambient Oxygen Conditions 1

AUTOR(ES)

Musgrave, Mary E.

RESUMO

Two cultivars of wheat (Triticum aestivum L. cvs Sonoita and Yecora Rojo) were grown to maturity in a growth chamber within four sub-chambers under two CO2 levels (350 or 1000 microliters per liter) at either ambient (21%) or low O2 (5%). Growth analysis was used to characterize changes in plant carbon budgets imposed by the gas regimes. Large increases in leaf areas were seen in the low O2 treatments, due primarily to a stimulation of tillering. Roots developed normally at 5% O2. Seed development was inhibited by the subambient O2 treatment, but this effect was overcome by CO2 enrichment at 1000 microliters per liter. Dry matter accumulation and seed number responded differently to the gas treatments. The greatest dry matter production occurred in the low O2, high CO2 treatment, while the greatest seed production occurred in the ambient O2, high CO2 treatment. Growth and assimilation were stimulated more by either CO2 enrichment or low O2 in cv Yecora Rojo than in Sonoita. These experiments are the first to explore the effect of whole plant low O2 treatments on growth and reproduction. The finding that CO2 enrichment overcomes low O2-induced sterility may help elucidate the nature of this effect.

Documentos Relacionados

• Three Phases of Plant Response to Atmospheric CO2 Enrichment 1
• Photosynthesis and Growth of Water Hyacinth under CO2 Enrichment 1
• Does Leaf Position within a Canopy Affect Acclimation of Photosynthesis to Elevated CO2?1 : Analysis of a Wheat Crop under Free-Air CO2 Enrichment
• Acclimation of Photosynthesis to Elevated CO2 under Low-Nitrogen Nutrition Is Affected by the Capacity for Assimilate Utilization. Perennial Ryegrass under Free-Air CO2 Enrichment1
• Response of two pea hybrids to CO2 enrichment: a test of the energy overflow hypothesis for alternative respiration.