The goal of this project is to get you familiar with collecting data using MultispeQs and the PhotosynQ platform to help you take high quality data.
MultispeQs are able to measure photosystem II efficiency, non-photochemical quenching, and chlorophyll content. With a large collection of data, we’ll be able to answer big questions about plant health and photosynthesis.
Take three measurements per plant. Make sure the leaves are not dead or senescing - they should be reasonably healthy. Then try out different light sources and different plants to see how photosynthesis changes.
To get started, first find a plant. Then, with the android or Chrome app, answer the questions.
Be sure to match the angle of the leaf when you’re measuring.
Hit measure, wait one second for the device to receive the command, then fully clamp the leaf. The measurement will start automatically after clamping.
Accept the measurement if the trace is smooth and looks roughly similar to the image below. If the measurement is bad or the leaf isn't doing photosynthesis, you should get a warning or danger notification - in that case, find a new leaf and/or remeasure. Over time, you'll develop an intuition good versus bad data, and you can always post questions to the forum if you are unsure.
- Leaf Photosynthesis MultispeQ V1.0
Measures many photosynthesis-related parameters in <15 seconds, including:
- Chlorophll Fluorescence: Phi2, PhiNPQ, PhiNO, NPQt, qL, LEF
- Relative Chlorophyll: SPAD
- Proton Motive Force: ECSt, vH+, gH+
- Absorbance at: 450, 535, 605, 650, 730, 850, 880, and 940nm.
- Leaf Thickness (in mm), angle, and cardinal direction
- Leaf Temperature and differential from ambient temperature
- Environmental conditions: PAR and ambient temperature/pressure/humidity
It's not practical to fully describe what all of these measurements mean here. If you want to learn more, a good place to start is this video: https://www.youtube.com/watch?v=pU5vOtE1wE8 . Check the PhotosynQ youtube channel for other videos explaining photosynthesis and related parameters.
This article is also helpful http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3040.2007.01680.x/abstract. It's paywalled, but email email@example.com to request a copy.
If you want to see the exact calculations for each parameter, please see the associated macro called "Leaf Photosynthesis MultispeQ V1.0".
Finally, there are two publications about the MultispeQ Beta device covering many of the below parameters and comparisons to commercial instruments. While that is technically an older model device, the calculations and comparisons are still true for this protocol. You can find them at the Royal Society for Open Science, and <still waiting on this one!>.
- Plant Type (Multiple Choice with images)
- Plant Height (Multiple Choice)
- Leaf Location (Multiple Choice)
- Leaf Number (Try Auto Increment) (Multiple Choice)
- Optional: Genus and Species (lowercase) (Short Answer)
- Take a Picture of the Leaf (Take a Picture)