From Teosinte to Maize

hopeacceptableΛογισμικό & κατασκευή λογ/κού

28 Οκτ 2013 (πριν από 4 χρόνια και 16 μέρες)

70 εμφανίσεις

From
Teosinte

to Maize

A
G
enetic Journey

Scientific name:

Zea

mays

spp.

parviglumis

How did we get from this…


www.historyforkids.org/learn/food/corn


To this….?

http://soilcrop.tamu.edu/photogallery/cornsorghum+/images/corn%20ears.jpg

A significant difference

http://www.nsf.gov/news/mmg/media/images/corn
-
and
-
teosinte_h1.jpg

Morphological Differences Between
Maize and
Teosinte

Maize:


rigid, 3
-
12 ranked rachis with solidly attached
grains


grains require human intervention
for dispersal and propagation.


Rachis segments bear
pairs

of grain bearing
spikelets

oriented
perpendicular

to rachis axis.


Open fruit case


Cont. Morphological Differences


Teosinte
:


Two
-
ranked rachis that naturally
disarticulates.


Single

grain
-
bearing spikelet per rachis,
oriented
parallel

to rachis axis.


Grains are protected inside closed fruit case.


Comparison



http://teosinte.wisc.edu/morphology.html

Which traits were chosen?


Early “farmers” did not want seeds to fall off
easily. So they chose those individuals that
had very attached seeds.


They wanted many seeds per ear.


chose
those with mutations having several rows and
ranks.


They wanted big seeds


chose individuals
with the largest seeds.

When and where did it begin?


Earliest evidence of cultivation 6,250 years B.P.


Earliest evidence found in
Guila


Naquitz
,
Oaxaca Mexico


Earliest cultivators: Pre
-
ceramic hunter
-
gatherers using cave shelters.


Photograph of three
Guilá

Naquitz

archaeological cobs
.

Benz B F PNAS 2001;98:2104
-
2106

©2001 by The National Academy of Sciences

Cultural Significance of Maize

Project

http://tvnoticias.files.wordpress.com/2008/04/m
aiz.jpg

-
Pair up for this project

-
Use the internet to complete your


research

-
You will have three class periods to


work on this

-
Compile your findings into a power


point presentation

-
Be prepared to present your project!

-
Follow your rubric closely!


References


Benz, Bruce, F. (2001). Archaeological evidence of
teosinte

domestication
from
Guila

Naquitz
, Oaxaca.
The National Academy of Sciences.
Retrieved
from
http://www.pnas.org/content/98/4/2104.full

on 9/3/2010.


http://www.koshland
-
science
-
museum.org/exhibitdna/crops02.jsp


http://teosinte.wisc.edu/morphology.html