Douglass College, Rutgers University, april 16, 1980

How chromosomes have been used to tr.ce the origi: and migration of
races of maize in the Americas.

LT. INTRODUCTION.

1. Reason for topic selection: Mysterious origin of the maize plant.
The range of its diversity, both morphologically and in its
chromesomes. The latter in conjunction with the former traces
the origin of the races with considerable precision.

é. Conclusion from study: considerable antropological significance:
Vonfirms, clarifies, tells much about relationships of areas of the
Americas and of the type of agriculture within areas.

3. Maize, cannot propagate itself. Must be man planted. Seeds must
be selected but what seeds are selected? The viability of the seed:
need for constant renewal.

4, The importance of the maize plant in the ULS. what is grown?
where did the different types of maize come from?

5- Most persons so far removed from agriculture that the importance of
maize in the US may not be appreciated. It uses:

Food: Cattle, hogs, poultry; absolutely basic to our economy.

"3 Corn-on-cob; canned corn; cornflackes; corn meal; hominy grits;

corn starch; corn oil (Mayzola); corn syrup (glucose to
fructose by enzyme treatment}; pop-corn; corn-liquor:

Commercial products: paper products, construction materials, cdramics;
paints, explosives, enzymes, pharmaceutical products,
corn-cob pipes!

Supermarket: over 1000 items with some corn product in them.

6. Corn grown for different products not the same: yellow and white
corn starch; sweet corn. Cattle corn. All from selected strains
of maize. Where did trese strains come from? How did we get to
use them as they are used now? This takes us to the varieties of
maize, its strange origin and diversity.

Il, THE ORIGIN OF Mala GROWN IN THE KMKKX&K UNITED S?.Tus al PRESANT TIM,
Qk UNTIL very recently.

1. Goes back to the development of hybrid corn and its phenomenal take-over
within a very few years. In 1933, estimated that less than % of
1 @ of maize from hybrid techniques. By 1945, 90% hybrid corn.

2. Before 1933: what maize grown in the U.S. From maize that was in
area: Indian tribes to early farmers and their selection methods.
Open pollinated varieties: Named from farmer who selected it, from

area where grown, some fancy name: Country Gentleman, Golden Bantam
sweet corns here. Now, snecial hybrid varieties have equally
fancy names: Indian Chief, etc.

3. Harly maize in U.S. Areas: Indian maize, arizona, New Mexico, Texas
Oklahoma, north from UVklamoma;
(2): Northern FPlints: North east to Northcentral. sarly maize.
(3): Southern dents: Virginia and south.

4. Hybrid maize in U.s. developed mainly from two major sources:

Northern flints by Souther Jents, and selected strains among them.
Other strains not grown; much of it lost. Loss ment loss of

otential germplasm.for improvement of maize. This type of |
Poss going on all over world for all types of crops. ery serious

Situation(in short run).
Preservation of some pre-hybrid maize from Indian tribes and from
other parts of the U.S. William L. Brown, President, Pioneer
Hi-Bred International, formerly Pioneer Hi-Bred Vorn Company,
started by Henry Wallace.

Method of corn breeding by hybrid methods: Shull, Cold Spring Harbor.
1908: The com. osition of field of corn. Maize very heterozygous.
Self pollinated, over several generation, would segregate a viriety
of types of plants and ears. Heterosis: HYbrid vigor. Crossing
inbreds to each other. Some showed remarkable vigor.

Slow appreciation. During 1920s some experimentation at ag
experiment stations and with encouragement of maize head man in
U.5.Department of agriculture. Henry wallace, early recognition.
Uther followed. in less than 10 years, massive take-over of
hybrid corn. Development of seed companies that made their own

The general background for nearly all corn grown: economic reason
initially: Texas cytoplasm. Male sterile. The 1970 disaster:

The potentials for such a disaster: the importance of maize in our
very existence here in the US. Now obvious; no longer many small
farms, dis ributed over country, using their own selected materials.

The situation recognized by some botanisits by m@# mid-ninteen fifties.
fheir fears resulted in action. This action responsible for my

 

7. Shull, 1909: Pure line method of improving maize plant.
hybrids.

8.
spread of fungus deseuse.

9.
participation the xmm maize race story.

Lil. THE STAR? OF THe STORY OF MaAIZS Ravis

1. Diversity of maize in the americas long recognized.

2. Several botanists collected maize from parts of americas and
attempted to classify the types. Very restricted study.

3

Maize grown in many parts of the Americas over the centuries. Result
of man selections over these centuries, there arose many different
types of maize. Hach Indian tribe developed its own types and
strains, and preserved them, or modified them.

Their selections: #lour corn, popcorn, sweet corn for making beer
(chicha), ceremonial corn. xtreme im.ortance in parts of the
sme “icas. This shown by areas where maize grown before
Columbus. SulD# 1 (wWeatherwax, map of maize distribusions).

Note areas of dense maize growing. The areas of little or none:
many of these, maize came in only late, 500 AsD or later.

The early areas of maize developme:.t: in regions o: heavy speckling.

Selections for pigments in plant and ear: Andean maize, most
prevalent. kxamples of pigment in color: SLIDEs 2.36

ixamples of ty,es of ears: the different races:=distinct strains.
BLIDE 4,

 
-3-

IV. THe BuGINNi Gs OF AN SXTHNSIVe STUDY OF MAIZH IN THN aMekICas.

1. Began in 1940s. The Rockefeller Foundation-Mexican government
convract to improve agriculture in hexico. Instig::ted, 1943.

2. The areas covered, varicus crop plants. Wheat (green revolution),
maize, potatoes, etc. Borlag, wWellhousen, wheat and maize.
Young men, entusiastic, energetic.

3. Ihe maize roject: If improvement is to occur, must know what maize
types are available. The decision to collect maize all over Mexi¢o.

The mode of collection: 10 to 15 ears from each farmer to determine
what maize he may be growing.

Number of tollection trips made to cover the whole country.

4, All maize grown was from v rieties known in the region where grown.
No hybrid corn as was developing in the U.S. Much greater
diversity of types.

5. The analysis: maize ears browght to Chapingo (Ag School, Rockefeller
Foundation sectio ) and placed on tables. Matching of types
then occurred, What appeared to be hybrids of types clearly
distinct from one another ordered. Then, plants grown from
this classificition to register comparisons and to reclassify, if
necessary.

6. An example of this classification method and the consequences of it:

Eplomero Toluquefio, Cacahuaciutle, Cénico, the cross of two Suspected
parents. SLIDE.95. (Names, Palomero, local in Valley of Toluca;
Cacahuacintle= Caca, cocoa; cintle = maize. Maize with cocoa-like
kernels. Common mode of naming maize races by Indians.

Parent restriction in growth. The nature of kernels. The otvious
distinctivns: Morphology, starch --pop, hard flint; soft starch.

The importance of the hybrid: a new race, like the open-pollinated
varieties in the U.S. before hybrid corn took over. Kept that way

by repeated selections for type. The effect of this hybrid race

in Mexico: as itself, and as it contributed to other rices; the
limited distribution of its importance to races, and the significance
of this for tracing the origin of the races. SLIDE 6 Wellhausen
Fig. 32, Cénico distribution. (Chromosoues and origins. )Verifications.

7. The publication, Harvard Univ. Press in English, 1952. In Spanish, 1951.

Wellhausen and colleagues. Extraordinary document. Recognized
25 distinct races, and many hybrids between them. The distinct
races divided into 5 categories according to methods used and
mainly, an exceptionally active intuitive perception:

(1). Ancient indigenous. 4 races
(2). Precolumbian exotics. 4 races
(3). Prehistoric mixtures. 13 races
(4). Modern incipient races (new combinations from itroductions
of foreign maize, hybridizing with indigenous maize). 4 races
(5). Poorly defined races. 7. Our contribution to unraveling
this class.
8. Subsequent collections and analyses of races over the Americas followed
this pattern of procedure and its publication mode. The
beginning of my entrance into this project.
Ve THE FORMATION OF THis COMMITTEE FOR PRAsERVATION OF LiDIGENOUS S?RaTWS

1.

Vi.
1.

2.

Of MATAR, NRC:NAS. 1954-1955.

The impression made on botanists and agriculturasts of the Races
of maize in Mexico study: brought attention to the diversity of
maize types, the effects of widely diverse germplasms from
maize introduced crossed with maize indigenous to territory.

Hybrid-maize; recognition of its limited germplasm selection and
toss of potential germplasms through neglect to continue open
pollinated varieties in indigenous regions.

Fear that this same situation would occur over the Americas with
loss of much of its extraordinary germplasm potentions, whereby
selections had been made over hundreds of centuries of selection
for mutations of the regulatory type and the nucleotide types.

Commettee functioning in cooperation with the Rockefeller Foundation.
Selections made all over the Americas as they wer made in Mexico.
Studies of races in territories followed collections in same manner.
Publications for each region examined:

Mexico, Guatemala and Central America; Colombia, Venezuela,
The Caribbean Islands, Ecuador, Peru, Bolivia, Chile, and
one inforporating Brazil, and adjacent agrentina, Paraguay,
and the Guianas.

One man o:. committee had theory about the chromosores; their
distinctive constitution differences according to elevations where
races grown. This required knowledge of chromosomes at one stage
in development of plant: the prophase of meiosis in "pollen mother
cells" where chromosome from ear parent synapsis side-b-side with
chro.uso me, homologous, from pollen parent.

June, 1957. Visit to C.S.H. for another purpose. <Asked if I wo.ld
be willing to train a person for such a study in Peru. My answer:Yes.

Winter, 1957-1958. Training program in Ag. Schall, outskirts of Lima.

Following year, request to do same in Volombia, South America.

My answer was Yes. Difficulties arose rega-ding person to trains.

I decided, best for me to go directly to Colombia and eamine soe

of the material already collected, stored in bottles in the deep-freeze
Decision to work there for 6 weeks and then return to the U.3s.

Period, from December 1978 through January 1959. Worked at

Medellin, where maize grown for this study and adjacent to the

Agr. School, supported by the Rockefeller Foundation.

THE COLOMBIA BXPuRTHNCE.

Given bottles with pollen mother cells in them, collected from
individual plants of races in s#cuador, Bolivia, and Vhile, that
were considered to be certai:.ly indigenous to the area, not recent(very)
introductions. Bottles and data available gave: name of country,

name of race, collection number to identify just where collected,

and elevation where collects. Missing, information on exact location
where each race collection was made. This information was at the
Station in Bogota. It proved to be important.

What my job was: to examine the chror:osone at the pachytene stage for
any differences that might appear in them, particularly the knobs,
enlarged deepstaining components. Necessary to explain them as these
proved to be the key to this study of origin and migration of

races in the Americas, along with two other or three other maize
chrouosomal types.
3. The chromosomes: Illustrations.
DE 7. Morgan photo.
2, - McC. photo medium to large knobs.
SLIDE 9. Kato photos; heterozygous knobs.
hh LO. Diagram of knob positions, potentials. Abn. 10 and B-type.
4. Mode of examining material: completely random, without plan as I was
not really interested in the job. It was a face-saving job only.

N

Pick a bottle, record the chromosome cunstitutions for each plant:

For each chromosome: pr.sence or absence of a knob at knob-forming
position, and for eich homologue.
If present, size and shape of knob recorded.

If any other change noted, was recorded.

d- After about two weeks of intensive work (early in morning and all day).
noted something strange: All plants at high elevations had the
very same chromoso e constitution: no knobs except a small one,
homozygous, in long arm of chromoso:ie 7. Wexe Two exceptions, and
these proved to be very important for conclusions.
In loser elevations, other knobs began to appear. ‘Some were
medium sized, some were large.
In Ecuador, at low elevation, sever:l races at an incredible number
of very large knobs. Nearly all knob forming regions occuppied.

Mangelsdorf theory‘reason for my being in Peru and Colombia. The
higher the elevition, the fewer knows one would find.

I began to wonder if Mangelsdorf might be right. Asked the maize
man responsible for the maize work at Medellin, if he had any
material from plants collected in the spur of the Andes that
enters Venezuela. His answer, Yes, and he brought some to me.

The Venezuealan highlands collections: Completely filled with very
large knobs. The knobs, remain as distinct deep-staining roundihn
hodies in nuclei. Whe nuclei looked as if they were filled with
marbles! Obviously, Mangelsdorf theory not working.

Began to recognize that the knobs were conservative. Finished my
period in Medellin and off to Bogatdé to place collections on maps.

To place each collection on a map of the country where collected took
a week with excellent and enthusiastic cooperation with maize
persons in Colombia, particulaty Dave Timothy who became as
excited as 1 about the results, as they were develophng from
the maps.

Became clear that 1) knobs were very conservative. ‘The Andean
complex of small knob in chro osome 7 long arm, extended almost
unaltered from Ecuador through Boliva and Chile.

The Venezuelan Complex extended along northern shore of Ecuador.

The areas of hybridizations: Andean meeting Venezuelan or other
complexes could be readily observed, geographically.

My conclusion: Centers of origin of maize development: start w th
one type. Its expansion, then introductions later, then
hybridizations.

Where were the centers? If we examined maize from all over the
Americas, we should find these centers.

Transmission of this concept to Wellhausen by limothy. His
enthusiastic response. Invitation to try my theory in Mexico.
THE MBALICAN pxAPURIBNCE.

1. Summer, 1959 and winter 1959-1960 in Mexico, Uhapingo in summer where
plants grown; winter in Mexico city examing collected materials.

 

2. The races examined:

Collections of the 25 races described in wWellhausen publication.
Vollections of some typical races from Guatemala, Honduras, El
Salvadore, Nicarauga, Costa Rica, Panama, and the Curribsean islands

3. The blind method of examining, to avoid bias.

4. The analysis of the results. Exciting. Excellent confirmation of
anticipations. Much of Wellhausens predictions of origins of the
races confirmed.

5. Complexes : no knobs, small knobs, medium size knobs, and large knobs
began to fall into place plus the miztures, the introductions and
thehe contributions within the new loc.tions,.

6. Subsequently, Longley and Kato. Extended materials of Guatemala and
the Caribbean Islands, and Ventral America.

7. Decision to cover the Americas from material collected. Needed
people to work on the chronoso.ies at different locations.

8. The decision, to train persons from Latin America at the North
Carolina State University at Raleigh. Contract there with the
Rockefeller foundations for maize work.had preceded.

VIII. THE RatwIGH nxt oRTENOK.

1. Persons: two from Brazil, one from Argentina, one from hexico.

2. In cooperation with faculty there and with William L. Brown
training program advanced. Degrees given.

3. Two of the 4 worked out very well. Kato from Mexico, and Blumenschein
from Brazil. Returned to their countries and started examining
races, and collections made in Brazil and Venezuela to increase
materials available.

 

1. Meetings each year, for about 6 weeks, to examine and discuss mat
inYormation collected for year, and plan for that of coming year.

2. Gradual recognition of xMtegxe uniqueness of study and its effectiveness
in interpreting the origin and migration of the races.

3. The final monograph: hundreds of tables and maps. Integrated for
ready retrieval. some of the conclusions will follow after
a few examoles are given of mode oi. operation.of this study.

A. THE OVeRavaL STUDY,
1. Where collections made. North and South america. SilDeS 11 and 12.

2. Some examples showing how the study integrates relationships:
Importance of special knobs with very limited distributions.
Will show a few of them here to indicate metiods used.

3. wAahiPLas:

(1). SLIDE 13. 16, long arm. position 1. sapalote, Tepecintle.
uatemala hi,hlands. Introduction to highlands south.
(2) sbije 14. 4 shart arm. Large and Medium. Coastal.

(3) Dd 7 7 short arm; barge knob. Nal-Zel, dapalote
Voistal, Arc in Guatemala, Venzuela. Perola, Guianas,
toraima. Panama, Voa:tal Trop. *lint-Tuson. Trinidad.
Cuba.

(4). SLIDE 16. Central mesa, Mexico and So. west U.s.
1 long arm, large and medium knob. Ventral Mesa dn highlands
of Guatemala. Central Mesa and north and north west (Cénico
germplasm, originally from Palomero Toluquefo.) Introductions
in Central America.

(5). Chromosome 7 long arm. SLIDE 17. Small chromosome.

(6). SLIDE 18. 2 short arm, small knob. Guatemala to south. western
en to Koraima. Highlands of Guatemala into Yucatan
Highlands of Guatemala and Central Mesa. Central Mesa north
through central region. pouth America: i:trocutions.

S&L. GENERAL CONCLUSIONS.

5.

The centers: Knobless, Small knob, Large knobs, medium knob.

The integrations, the consequences for races, the migrations, the
introductions, the consequences .

The land and see travels demonstruted.

The anthropomorphical implications: Maya maize origins, Andean maize
origins and timing. Timing of introductions into Andes Mexico
for distinctive pop corn. Venezuela much later (Colombia, adj. prob.

The origin of the various knob types, originally: Mexican Teosinte.

XII. The teosinte contribution to chromosome constitutions of maize and
probably to its origin, and certainly to its germplasm subsequently to

early selections. SLIDES 19, 20, el.
he Indian tribes as plant breeders.
SLIDES

1. MAP of the Americas, Weatherwax maize distribution in "ancient"! times.
2. COLOR. Commercial maize; mosaic pericarp. Purple aleurone.

3. COLOR. PY’, Sector of "dark crown" and dark pigmented cob.

4, Hars of races, differences. Mangelsdorf. Fig. 9.1

5. Hars, Wellhausen Fig. 36. Palomero Toluquefio, Cacahuacintle, Cénico
and hybrid of parents.

6. MAP, Wellhausen Fig. 32. Distribution of Cénico in Mexico.
7. Pachytene chromosomes. Morgan photo.

8. " " « McC photo.

9. " " - Kato photos. Heterozygous knobs.
10. DiaGRAM, knob locations, 10 chromosoues of maize. Kato.
ll. MAP. Collections made in North America.

12. " . Collections made in South America.

13. " . Distribution of 10 long arm small knob, position 1.
14. +", a : 4 short arm, large and medium knobs,
1. ". " " 7 short arm, large knob.

16. ", " " 1, long arm, large and medium knobs.
17. ". " " 7 long arm, small knob.

18. ". " 7 2 short arm, small krob.

19. MAP. Mexican states. Wellhausen
20. Photo of Teosinte. Mangelsdorf Figure 3.4. Chalco Teosinte
2l. Hars, Maize inbred x teosinte with parents.
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