I have a nice picture from an isolated farmhouse in the western
Himalayas, just after the maize harvest. The woman is selecting ears for
seed, and putting them in a basket. The man is beating the remaining
ears with a stick, knocking off the seeds. (Actually, these things are
going on simultaneously.) Among the corn ears are short, fat ones and
longer, skinny ones; ones with strongly spiralled rows and ones with
straight rows; ones with relatively (compared to ear size) big seeds and
ones with relatively small seeds. Needless to say, these people are not
working with hybrid seed. (It is almost a week's walk to the nearest
road, which is not paved.) A colleague I showed this to said that I was
wrong in thinking that these visible variations in ear appearance were
indications of genetic diversity; she said that they might just be due
to site differences from plant to plant. Any wisdom on the topic out
there? I'd like to tell the students the truth as much as we can guess
it, without gels.
Another colleague said, "Think of the disease resistance genes in that
pile of maize!" Probably no pesticides used, but I didn't ask. Not in
the picture is one other nice feature, the spirit statue that stands
outside each house in that part of the valley, left over from an ancient
local religion.
--Gini Berg
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Dr. Virginia Berg
Professor, Plant Physiology
Biology Department
University of Northern Iowa
Cedar Falls, IA USA 50614-0421
bergv at uni.eduhttp://www.uni.edu/berg
office: 319 273-2770
fax: 319 273-2893
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