Original video: https://youtu.be/0yGLrabi6zo
KURSUS UNTUK RAKYAT : COURSES FOR PEOPLE
Delivered on: 21 AUGUST 2022
This lecture focuses on understanding and creating light response curves, a key tool in plant physiology. Explained how to set up and use a Portable Photosynthesis System (LI-6800 & LI-6400XT) to measure photosynthetic rates under varying light intensities. It emphasizes the importance of acclimating leaves to controlled conditions before measurement and interpreting the resulting biphasic curve. Key information derived from light response curves includes dark respiration rate, light compensation point, quantum efficiency, and maximum photosynthetic rate (Amax). Highlighted how light response curves can reveal a plant's adaptability to sun or shade conditions, providing insights into its physiology and potential responses to future environmental changes.
A light response curve can provide indications of the:
Dark respiration rate: The photosynthesis rate with no light,
Light compensation point: Absorbed quantum flux for which photosynthesis and respiration are balanced
Quantum efficiency: Initial slope of the assimilation rate, and
Light saturated photosynthetic rate (Asat).
Video Timestamps:
00:00 Recap attending light course fortnight back (https://www.youtube.com/watch?v=ORpE4y4ZuVg)
03:40 Basic Making Graphs for Light Curves
04:00 The components of abscissa and ordinate x-y axes
09:33 The number, letter and F menus in LI6400XT
10:00 Plotting light curve from data points
10:40 Biphasic nature of light curve
11:20 Information can be derived from light curve
11:39 Light curve indicates Dark Respiration rate
11:58 Light curves indicates Light Compensation Point LCP
14:50 Light curves indicates Quantum Efficiency
17:25 Light curves indicates Maximum Photosynthetic Rate Amax Assimilation
18:23 Photoinhibition due to excess light
19:30 Light curves tells if plant more towards shade type or sun type
25:55 Know the reason behind actions. Don't entertain crazy clueless supervisor
31:30 Setting up environments in LICOR 6400XT and LI6800 chamber to acclimate leaf
39:00 To choose leaf: Determine the plant phyllotaxy ( leaf arrangement)
40:00 Choose fully expanded leaf, level 3 to 5 from the top like in Choy Sum
40:21 Don't count leaf bud or primordia as a leaf count
43:10 Don't use broken leaf
45:20 Choosing leaf of palmate morphology like Okra
56:40 Sings of acclimated leaf in the chamber. Ensure this before run Light Curve
1:04:26 Adding water to Stuttgarter Masse column in LI6800
1:06:15 Press square bracket ] on LI6400 to see current graphs to determine acclimation level of the clamped leaf
1:32:57 Extra - Intro to do A/Ci Curves CO2 response Curve
1:45:40 Why CO2 concentration set for CO2 curve not similar like light curve.
Keywords: Light response curve, Photosynthesis, Plant physiology, LICOR machine, Photosynthetic rate, Light intensity, Acclimation, Biphasic curve, Dark respiration rate, Light compensation point, Quantum efficiency, Amax, Photosynthetic efficiency, Sun plants, Shade plants, Light adaptability, CO2 response curve, Kelvin cycle, Leaf morphology, Chlorophyll fluorescence, Electron transport rate, lesson
Location
Faculty of Agriculture, Universiti Putra Malaysia
Fakulti Pertanian, Universiti Putra Malaysia, 43000 Seri Kembangan, Selangor
XPMM+9J Seri Kembangan, Selangor
2.9845517506267742, 101.73803356324866
Attribution 4.0 International — CC BY 4.0 - Creative Commons
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