Archimedes Plutonium wrote in message ...
moments ago I wrote:



P.S. in my earlier post I was asking whether some method exists that tells
us how much photosynthesis is going on per square area of a cotyledon leaf
compared to a mature leaf. In light of the new understanding above that a
cotyledon is a different "organ" so to speak, perhaps we can use cotyledons
as a gauge.

By gauge I mean that if there exists a math relationship of size by mass to
existence of a cotyledon then also the size of the cotyledon should also be
correlated to size of seed. A strawberry seed is so tiny compared to a pear
seed that the cotyledon of a strawberry should be *relatively* larger than the
pear cotyledon per size.

And so the mass of seed and the size of cotyledon (per mass also) may indicate
how much photosynthesis is taking place between a mature leaf compared to
a cotyledon leaf.

When it all comes down to the essential parts, it is photons of light and
area of photosynthesis and of course mass of the plant structure.

(1) photons
(2) unit of area
(3) mass of plant structure

Has any scientist worked out those 3 parameters on cotyledon?

Unfortunately, most of the information on cotyledons I have comes from
textbooks and not research papers (and the textbooks are notoriously
poorly bibliographed). From what I have read, though, there will be
more constraints on the system than due to the functionality you have
mentioned because the cotyledons are also sources of starch storage in
the early plant development. To a great extent this will come from
the seed mass, and so there does seem to be an opposite relationship
at work here too: that cotyledon size will likely not grow that large
for small seeds. If you couple this with the statements found in a
couple of books that photosynthesis occurs less in the cotyledons
(probably an over generalization, but the observation is probably one
of measuring fraction of chlorophylls which one can extract from a
cotyledon versus mature plant leaves), then you probably have a
limiting factor to size. In fact, it would appear that overgrowth may
be counteractive, and that the size factors due to photosynthetic
capabilities and plant food storage might be more applicable to the
true leaves. And of course, there is the crucial factor of
transpiration and the environmental niche which the plant resides in,
where the size differences can be extraordinary (desert plants versus
tropical plants for the extremes).

But I do think there are likely important relationships here, and if a
literature search turns up empty, doing the biometric studies would
certainly be a proper exploration for you. I don't think any of the
relationships will be linear (which in my book is a plus!). Good luck
in your quests for knowledge!