Re: HYB: seedling survival comparisons

I can always make up some wild theories about nearly anything <g>.  My
gut says there might be. If there is a link, I'd assume it's
coincidental, not a necessity.

What I've thought is that plants that thrive in the vale have the
physiology to cope with highly variable environmental conditions.  They
can take both abrupt changes in temperature fall, winter and spring, and
alternating extreme drought and heavy constant rain in hot weather with
minor cell death.  That implies they either have mechanisms to resist
damage or mechanisms to rapidly repair damage.  I don't know whether or
not those same mechanisms would work the same way to resist or recover
from disease, but it seems they would, at least to resist disease.

From what I read about seed dormancy (all species, not just irises), the
chemical reactions that have to take place inside the seed and seed coat
can go either towards breaking dormancy or increasing dormancy.  A seed
that doesn't easily come out of dormancy isn't going to germinate at the
first hint of warm weather in the middle of the winter.  The mechanisms
are very different for disease resistance and difficult germination, but
I would expect them to both be present in cultivars that thrive here.

My theory about both types of survival here is that they are linked to
slowed response (i.e., slower growth, slower germination) to changing
environmental conditions.  Has to do with carbon allocation (what the
plants do with photosynthate - use it to grow, for defense, or storage
for use in bad times).

Those are my theories.  Is there a connection?  Beats me <g>

<Any theories on why this might be?  Do you think there is a connection
between the difficulty of germination and the disease resistance of the
cultivar?
    Betty W. in  South-central KY Zone 6>

--
Linda Mann east Tennessee USA zone 7/8
East Tennessee Iris Society <http://www.korrnet.org/etis>
American Iris Society web site <http://www.irises.org>
talk archives: <http://www.hort.net/lists/iris-talk/>
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