sphinkson at worldnet.att.net
Tue Jul 13 05:23:45 EST 1999
GOOD answer !
Ever consider a job in diplomacy?
Lets get out the dissecting scope and count flower buds...
Ross Koning wrote:
> At 9:19 PM -0400 7/12/99, A. Cary wrote:
> >But a young Cauliflower head is meristematic tissue.
> Andy is right...the key word is YOUNG!
> At the risk of getting boring, I'll reiterate
> that we have to be careful about development...
> How OLD are we talking? The head of cauliflower
> has a range of primoridal stages depending on
> its AGE. I think, making a few assumptions about
> responses, that EVERYONE has been basically right
> on this question but that various writers are
> talking about portions of a head that are at
> quite different developmental stages.
> Those who say...it is flowers... are talking
> about cauliflower that you are growing and allowing
> to continue to develop. Indeed from base to tip
> and from outer to inner, these primordial structures
> develop into flowers. As someone has said, they
> make an impressive inflorescence...eventually.
> BUT ALSO...
> Humans happen to harvest this inflorescence when
> it is very YOUNG and so, while some of the peripheral
> primorida may be fully developed into flower buds,
> the central tissues within the floret, and certainly
> the central florets in the head are STILL MERISTEMATIC.
> So those who say...it is meristem...are right too,
> depending on how fully developed this head is. If
> you probe for meristematic RNA later (at a time beyond
> normal harvest!!!!) it will no longer show that
> gene expression...even in the central florets of the
> So, if you focus on the end product or are letting
> your plants grow, the final product is INDEED flowers.
> If you get your cauliflower in the grocery, or if
> a technician cuts it in the field to bring it in for
> your physiology/genetics/histology at the usual harvest
> stage, then what you think of as the final product is
> MOSTLY meristematic.
> How "committed" this meristem is to flower production
> is probably open to test...and an important criterion
> for this test would have to be the developmental stage
> (plastochron?) for each bud. I haven't a clue as to
> how you would develop an index to identify each bud in
> such a vast inflorescence in order to attach a developmental
> frame to state when it is "canalized" into floral development.
> So I think we are going to be wallowing in chaos without
> an essential frame for discussion.
> Ross Koning | koning at ecsu.ctstateu.edu
> Biology Department | http://koning.ecsu.ctstateu.edu/
> Eastern CT State University | phone: 860-465-5327
> Willimantic, CT 06226 USA | fax: 860-465-4479
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