Fellow researchers
I grew lettuce under white LED lighting.
The light intensity was rather low (less than 200μmol/ m2s).
The plants grew to have a shade avoidance-like morphology which enabled them to (almost) reach the LED lights. As a result the top part of the leaves was under higher light intensity.
Is it possible that the lettuce plants were acclimated to low light intensity (reason the photosynthetic rate was low) but because the top of the leaves were under high light intensity, light acted as a signal which made the rest of the leaf respire more, not being able to understand that only the top had high light intensity?
While growing the same lettuce at high light intensity both the photosynthetic rate and respiration were high. Same for the greenouse treatment. In both these cases the leaves were under more uniform lighting conditons.
Has anyone experienced something alike?
Does it make sense for light to act as a signal that affects the whole leaf and not just a part of it?
Thanks in advance.
It is due to reduced light intensity, the reduced light intensity shunts PSII you can measure the Fv/Fm for urself
this reduces net photosynthesis
they will also have larger leaves I suppose and increase in Chl b as compared to chla
Sudershan Mishra
Dear Sudershan,
Thank you for your answer.
During the experiment there were three treatments.
Artificial lighting:
1) High light intensity (HLI 260-360)
2) Low light intensity (LLI 180)
Greenhouse treatment:
3)The light intensity was even lower than (2) for most of the time at this period (GT, 140)
a)I understand why the photosynthetic rate would be higher in HLI>LLI>GT and that was as expected.
b)What i did not expect was that the transpiration rate does not follow the same trend. It is more like LLI>GT>HLI
The LAI, leaf number, CHLa + CHLb, ΦPSII and ETR followed the same trend as (a) ( HLI>LLI>GT)
So my question remains the same.
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