Photosynthetic efficiency
nounPronunciation: /ˌfoʊtəʊsɪnˈθetɪk ɪˈfɪʃənsi/
The capacity of the photosynthetic apparatus to convert absorbed light energy into chemical energy (glucose) under given environmental conditions, typically measured as quantum yield or net photosynthetic rate relative to light intensity. Under abiotic stress, photosynthetic efficiency declines due to stomatal closure or non-stomatal limitations affecting light reactions and carbon fixation.
Plain English
How effectively plants convert light energy into usable chemical energy, which decreases when environmental stress restricts photosynthesis.
Etymology & History
Usage
"Photosynthetic efficiency declined sharply in heat-stressed wheat, limiting biomass accumulation and grain yield."
Style guide notes: Specify measurement conditions (light intensity, CO₂ concentration, temperature) when reporting photosynthetic efficiency values.
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Contrasted with
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Frequently Asked Questions
What factors reduce photosynthetic efficiency under stress?
Stomatal closure, damage to chloroplast structures, reduced enzyme activity, and excessive light absorption all decrease efficiency.
How is photosynthetic efficiency measured experimentally?
Chlorophyll fluorescence (Fv/Fm), gas exchange analysis, and oxygen evolution measurements are common techniques.
Why Test Candidates on This?
Regularly tested in plant physiology and crop production courses examining stress impacts on productivity.
Required skill level: Mid