dear halford
just a point on fluorescence terms:
qP is, more accurately, the parameter that reflects the steady state
operation of charge separation and stabilization, as you point out, to Qa
qN is to my thinking a catch out all term for many functions that
dissipate energy not used to do photosynthetic work. it is perhaps
largely qE but there are other components and their relaxation kinetics
are important in their resolution (in so far as they can be coherently
separated).
Lastly, fv/fm is a component that better reflects the electron transport
chain through ps2 (ie to Qb) as it is measured after dark adaptation when
all traps are open. if you are interested in quantum yields of electron
transport as calculated from fluorescence data you may wish to consider
Genty et al., 1989, BBA, v990, p97-92.
others in this group may dispute these simplified interpretations, but
they are useful to me. with them, i tend to not get lost in circularities
concerning interpretation of the terms but can focus on what the data is
telling me.
i hope this is helpful,
darren goetze
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dept of botany
univ of british columbia
vancouver bc v6t 1z4
canada
