CHAPTER 5
OPERATION OF THE JUNIOR-PAM
Also, three groups of saturating pulse data are displayed in Box (4).
Group 1 (Fo, Fm, Fv/Fm) includes data measured with a dark-
acclimated sample before light-exposure but Group 3 (F´ to Fo´) repre-
sent data obtained during illumination. Group 2 represents fluorescence
parameters characterizing the state of photosynthesis in the light. Some
of the Group 3 data, however, require fluorescence measurements with
the dark-acclimated sample that is Group 1 data.
Group 1
Fluorescence data from a dark-acclimated sample with actinic
light switched off.
Fo
Basic fluorescence yield (relative units) recorded with low
measuring light intensities.
Fm
Maximal chlorophyll fluorescence yield when photosystem II
reaction centers are closed by a strong light pulse (relative
units).
Fv/Fm = (Fm-Fo)/Fm; maximum photochemical quantum yield of
photosystem II.
Group 2
The group includes data of qP, qL, qN, NPQ, Y(NPQ), and
Y(NO) and, thus, matches the group of <Quench> data in the
<Val.> sidebar (see above). If Fo’ is calculated (see 6.1.2), cal-
culations of all 6 types of data require both, initial fluores-
cence determinations with the dark-acclimated sample and
saturating pulse measurements during exposure. If Fo´-Mode
is checked, the Fo´ is measured, and, thus, Fo or Fm fluores-
cence data are not required for calculations of qP of qL (see
Table 6.1).
Group 3
The group corresponds to the <SAT-pulse> data in the <Val.>
sidebar (see above) and includes F’, Fo’ and Fm’ of the last
saturating pulse analysis during light exposure but also data of
Y(II), PAR and ETR. Note that a tilde as prefix of value of Fo’
indicates the Fo’ is calculated as described in 3.2 and not
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