Which one is better RIDES, Leaf Photosynthesis MultispeQ v2 Protocls

Measurements, Protocols & Macros

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Hello, I have gone through the following manuscripts 1. Kromdijk, J., GÅ‚owacka, K., Leonelli, L., Gabilly, S. T., Iwai, M., Niyogi, K. K., and Long, S. P. (2016). Improving photosynthesis and crop productivity by accelerating recovery from photoprotection. Science 354, 857-861.enter link description here 2. Hubbart, S., Smillie, I. R. A., Heatley, M., Swarup, R., Foo, C. C., Zhao, L., and Murchie, E. H. (2018). Enhanced thylakoid photoprotection can increase yield and canopy radiation use efficiency in rice. Communications Biology 1, 22.

I understand that NPQ flexibility allows the plant to buffer the light-induced changes in ETR and thus regulate photosynthetic metabolism. NPQ or PhiNPQ or NPQ(T) or qE can be used as potential selection criteria for improving crop productivity. My Question is Using MultispeQ, which protocol is best for phenotyping wheat lines.

  • created

    Mar 2019

  • last reply

    Feb 2021

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    3

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Sebastian

Mar 2019

Hi Habib,

I would recommend using the Leaf Photosynthesis RIDES protocol instead of the Leaf Photosynthesis, since the ECS data, that is collected using RIDES, has been improved.

~Sebastian

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Milan Urban

Feb 2021

Dear Sebastian, Is it true that Leaf Photosynthesis RIDES no open/close protocol is using only 650 nm for calculating SPAD, instead of using all the diodes available in the "normal" protocol? Thanks, Milan

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Sebastian

Feb 2021

Hi Milan,

since Sean is the author of this particular protocol and I was not really involved in it, I had to go through the code to see what is happening. The SPAD part of the protocol is pretty straight forward and measuring the absorbance with multiple LEDs as you can see here for the pulsed_lights:

{
    "label": "SPAD",
    "pulses": [...],
    "nonpulsed_lights": [...],
    "nonpulsed_lights_brightness": [...],
    "pulse_distance": [...],
    "pulsed_lights_brightness": [...],
    "pulse_length": [...],
    "detectors": [...],
    "pulsed_lights": [
        [1],
        [2],
        [3],
        [4],
        [6],
        [8],
        [9],
        [10],
        ...
    ],
    "recall": [...],
    "environmental": [...],
    "averages": 1
}

Now, the macro on the other hand is pretty complicated. I worked my way through it and I think this is the location that is calculating SPAD (Line 782). In this case it seems like the macro is using the 650 nm and the 940 nm to calculate it, like in the documentation linked below.

I'm not 100% sure what you mean by normal protocol, but I guess is just Photosynthesis RIDES. It seems, the macro is the same and the way the calculation is done, too.

// Line 782:
spad_at_blank1[light] = MathROUND(
    100*MathLOG(
        (raw_at_blank1[6] / json.set[calib_set].recall["colorcal_blank1[6]"])
         /
        (raw_at_blank1[light] / json.set[calib_set].recall["colorcal_blank1["+light+"]"])
    )
,2);

I'm not sure what version of the MultispeQ you have and what firmware version you are running, but the latest "RIDES" protocol called "Photosynthesis RIDES 2.0" is using a new firmware command that makes the SPAD measurement so much easier. The measurement and calculation itself is done as described here.

I hope this is helping you a little. Please let me know if you have more questions.

~Sebastian