SPAD chlorophyll measurement

Knowledge graph centered on SPAD chlorophyll measurement with 71 nodes and 148 connections. Top connected: Ligusticum porteri, Delphinium, phenological mismatch, Asteraceae, Potentilla.

Method synopsis

Measurement of chlorophyll fluorescence using LI-600 to assess photosynthetic efficiency by quantifying light emission from chlorophyll molecules excited by solar radiation.

Synthesized from method descriptions across 9 papers using this protocol.

Procedure from a recent peer-reviewed implementation

Steps below were extracted from the most recent peer-reviewed implementation of this protocol in the corpus — <i>In situ</i> photosynthetic freezing tolerance for plants exposed to a global warming manipulation in the Rocky Mountains, Colorado, USA (2004), New Phytologist. The protocol was originally introduced by Biotic factors influencing feeding preferences of <i>Scaptomyza nigrita</i> (Drosphilidae) on its host plant, <i>Cardamine cordifolia</i> (Brassicaceae) (2011). Implementations in other papers (listed below) may differ.

1. Measure chlorophyll a fluorescence
   Measurements obtained with a pulse-modulated fluorimeter. Leaves were dark adapted for at least 15 min using leaf clips designed for use with the FMS1. Custom script written to automatically record Fo, FM, Fo', and Fs, with efficiency of excitation transfer measured as Fv/FM using a saturating beam of 14,256 μmol m⁻² s⁻¹ for 0.7 s
   Quantities: 15 min dark adaptation minimum, 14,256 μmol m⁻² s⁻¹ saturating beam for 0.7 s, measurements at five minute intervalsDuration: Measurements during ice freezing treatments, five minute intervals, overnight periodsConditions: Dark adaptation required, leaf clips used, saturating beams applied
   Equipment: Model FMS1 Hansatech Kings Lynn UK pulse-modulated fluorimeter, Hansatech dark-adapting leaf clips
2. Conduct in situ Cold Experiment (ICE) treatment
   At least three terminal leaves per target plant were enclosed in a cylindrical styrofoam chamber (25 cm dia × 30 cm deep). Liquid nitrogen stored to pressurize overnight in a 70 L Dewar flask to 85 kPa. Air temperature adjacent to leaves and stems was lowered by adjusting a valve on the Dewar to vent cold nitrogen vapor through a coiled copper tubing heat exchanger (10 coils, 25 cm dia × 20 cm tall) inside the styrofoam chamber
   Quantities: At least 3 terminal leaves per plant, chamber 25 cm diameter × 30 cm deep, 70 L Dewar flask pressurized to 85 kPa, heat exchanger with 10 coils of 25 cm dia × 20 cm height

Typical Equipment

• LI-600

Output Measurements

• chlorophyll fluorescence

Papers Using This Protocol (9)

Species Studied With This Protocol