plant phys use in breeding

[adwright at iastate.edu]

If I may put in my $.02 worth: 

The big obstacle IMHO is not so much the time it takes to do a measurement, but
rather to do a meaningful measurement.

Has anyone ever tried to do leaf photosynthesis or water potentials in a
corn field (or worse a soybean field?) What is being done is an observation of a single point in time and not a really good indication of the sum total of 
activity. What leaf was sampled? Was it shaded or in full sun? What was it 
like ten minutes ago? Was the wind blowing? Darn, theres a cloud coming! ;)

What we need to be thinking of (and it aint easy) is a way to take into account the whole plant response.

A real elegant way to apply selection is to use a "suicide screen". One of my
favorite ones is the selection of plants resistant to toxic amino acid analogs.
This is physiological selection, is it not? The plants that recover best tend 
to produce more of the amino acid. 

To continue along this vein suppose we wanted to select specifically for low 
respiration rate. What would be nice is to uniformly apply a chemical that 
penalizes the plant for respiring. I am thinking out loud now, but there must
be something that would do this. Anybody have any thoughts on this?
Allen