Okay, looks like there's just one more contribution to the popcorn question
to add to the summary. Again, thanks to all for the illuminating answers.
- Dave
~~~~~~~~~~~~~~~~~~~~~
>From: "Duvick, Don" <DUVICK at phibred.com>
To: "'Dave Matthews'" <matthews at greengenes.cit.cornell.edu>
Subject: RE: What makes popcorn pop?
Date: Wed, 14 Jan 1998 15:25:05 -0600
I'm not an expert on "popability" but I know it is not caused by a
single gene. Rather, each cell in the endosperm will or won't pop,
depending on whether its starch grains and zein granules are encased
with a tough storage protein. Those cells with such make-up are the
"horny" endosperm of the maize endosperm. Those cells in which the
protein encasement has fractured (at dry-down of the kernel) are in the
"floury" endosperm. In dent corn, horny endosperm is only on the
shoulders of the kernel; in pop corn horny endosperm is on the shoulders
and also over the top of the kernel. You can pop dent corn, but only
the relatively small horny endosperm will pop. I'm not at all sure
whether analogous conditions hold for the other cereal grains. Another
way to pop grains (oats for example) is to heat them under pressure and
then release the pressure suddenly (at least, I think I've read this, a
long time ago, don't take me as an authority on this!).
If you have some interest in the things I just described, my Ph D thesis
(Development and variation of the maize endosperm) at Washington
University, St. Louis (1951) describes much of this, although I don't
think I actually talked about popability. It also has some descriptions
of the transfer tissue in the endosperm, based on light microscope
observations of living tissue. Also, papers in the American Journal of
Botany (1955) and Cereal Chemistry (1961) deal with some of these
things.
Donald N. Duvick
>----------
>From: Dave Matthews[SMTP:matthews at greengenes.cit.cornell.edu]
>Sent: Tuesday, January 13, 1998 9:49 PM
>Subject: What makes popcorn pop?
>>Is popability a single gene? How does it work? Could it be transferred to
>wheat or oats or rice? Is "puffed" wheat etc. related?
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