Effect of air pollutants on the photosynthetic and dark respiration rates of Phaseolus vulgaris
The effects of continuous fumigations with pollutant gases on net and gross photosynthesis, dark respiration, respiration/gross photosynthesis ratios, root/shoot ratios, and chloroplast ultrastructure were examined. Plants of Phaseolus vulgaris L. Blue Lakes, were grown in paired plexi-glass chambers. Photosynthetic and respiration rates of 12-19 day-old plants were measured by infrared gas analysis. The plants were dried and root/shoot ratios calculated. A significant increase (28.9%) in gross photosynthesis of plants exposed to 10 ppm. CO was evident compared to the controls. Although net photosynthesis was not significantly affected by 0.035-0.04 ppm NO/sub 2/, gross photosynthesis, dark respiration, and R/G were significantly greater than in controls. Concentrations of 0.04-0.005 SO/sub 2/ resulted in significantly greater respiration and R/G ratios. This procedure resulted in significantly reduced net and gross photosynthetic rates. Ozone exposures of 10-20 ppm for eight hours a day, five days a week, resulted in progressively lower net and gross photosynthetic rates as the week progressed and R/G ratios were significantly higher. Ozone exposures of 6-8 ppm reduced net and gross photosynthetic rates significantly. Average root/shoot ratios of all exposed plants were significantly greater (14.8%) than those grown in pollutant-free air. The concentrations employed were comparable to the federal air pollution standards. It was concluded that these low levels of pollutant gases are capable of altering physiological activities which may result in reduced yield.
- OSTI ID:
- 6052967
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Ectomycorrhizae influences on CO/sub 2/ exchange and carbon allocation in Pinus
Root restriction as a factor in photosynthetic acclimation of cotton seedlings grown in elevated carbon dioxide. [Gossypium hirsutum L]
Related Subjects
AIR POLLUTION
BIOLOGICAL EFFECTS
CARBON MONOXIDE
COMPARATIVE EVALUATIONS
NITROGEN DIOXIDE
OZONE
PHASEOLUS
PHOTOSYNTHESIS
RESPIRATION
STIMULATION
SULFUR DIOXIDE
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
LEGUMINOSAE
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PLANTS
POLLUTION
SULFUR COMPOUNDS
SULFUR OXIDES
SYNTHESIS
560303* - Chemicals Metabolism & Toxicology- Plants- (-1987)