Y, / ;. i
Douglass College, Rutgers University, lipri1 16, 1980

,   --

How chromosomes have been used to tr.ce the origin. and migrcition of
    races of maize in the Americas.

1. Reason for topic selection: Mysterious origin of the maize plant.
   The range of its diversity,
    chromesomes.           both morphologically and in its
             The latter in conjunction with the i'ormer traces
   the origin of the races with considerable precision.
2. Conclusion from study:
   Corlfirms,         considerable anUrapologica1 significance:
          clarifies, tells much abolit relationships of areas of the
   Americas and of &tie type of agriculture within areas.
3. Maize,  cannot propagate itself.  Must be man planted.   Seeds must
   be selected but what seeds are selected?
    need for constant renewal.            The viability of the seed:

4. The importance of the maize plant in the ULS.  idhat 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 Ud may not be appreciated.   It uses:
    Food: Cattle, hogs, poultry; absolutely basic to oilr economy.
        II  : Co&n-on-cob; canned corn; cornflackes;
        corn starch; corn oil (Mayzola);     corn meal;  hominy grits;
                           corn syrup (glucose to

      fructose by enzyme treatmentj; pop-corn; corn-liquor!
   Commercial products:  paper products, construction materials, ceramics;
       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 strai:;s
    of maize.  Where did tnese strairis cor';e from`!
   use them as they are used now?            How did we get to
                             This takes us to the varieties of
   maize, its stringe origin and diversity.

1. Goes back to the development of hybrid corn and its phenomenal take-ovg:r
  within a very few years.   In 1933, estimated that less than 1/2 of
  1 $ of maize from hybrid techniques.  By 1945, 906 hybrid corn.
2. Before 1933: what maize grown in the U.S.  Prom 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, Gol(!en Bantam
    sweet corns here.  Now,
   fancy names;        special hybrid varieties have equally
            Indian Chief, etc.
3. Early maize in U.S. Areas:
   Oklahoma,            Indian maize, flrizona, New Mexico, 'Texas
   (2): North north from Oklahoma;
            ern Flints:
   (3): Southern dents:  North east to Northcentral. darly maize.
                  Virginia and soclth.
4. Hybrid maize in U.L. developed mainly from two major sources:
   Northern Flints by Youther :Jents, and selected strains among them.
    Other strrtins not grown; much of it lost. Loss men-t loss of
  P otential germplasm.for improvement of maize.   This tr pe of
     oss goin  on all over world for all types of crops.  5 ery serious
   situation in short run).
     f


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5. Preservation of some pre-hybrid maize from Indian tripes and from
  other parts of the U.S.
  Hi-Bred International,   vJilliam L. Brown, President, Pioneer
                 formerly Pioneer Hi-Bred Corn Company,
  started by Henry Wallace.

6. IL'let!Lod of corn breeding by hybrid methods:
   1908: The com,,osition of field of corn.   Shull, Cold Spring harbor.

  Self pollinated,                  Paize very hetkrozygous.
               over several generation, would segregate a v.riety
  of types of plants and ears.   Heterosis: HYbrid vigor.  Crossing
   inbreds to each other.  Some showed remarkable vigor.
7. Shull, 1909: Pure line method of improving maize plant.
  Slow agpreciation.  During 1920s some experimentation at lig
  experiment stations and with encouragement of maize head man in
  U.A.Department of agriculture.   Henry viallace,  early recognition.
   tither followed.  In less than 10 years, massive take-over of
  hybrid corn.  Development of seed companies that made their own
  hybrids.

8. The general background for nearly all corn grown: economic reason
  initially:  Texas cytoplasm.   Plale sterile.   The 1970 disaster:
  spread of fungus dese,ise.
  The potentials for such a disaster:  the importance of maize in our
  very existence here in the US.  Now obvious;
  farms,                            no longer many small
       dis ributed over country,  usijig their own selected materials.
9. The situation recognized by sor;le botanisits by &$a mid-ninteen fifties.
   Their fears resulted in action.  This action responsible for my
  participation the AAn maize r:-lce story.

1. Diversity of maize in the iimericas long recognized.
2. Several botanists collected maize from parts of americas and
  attempted to classify the types.  Very resdricted study.
3. Maize grown in many parts of the Americas over the centuries. RestAt
  of man selections over these centuries,  there arose many diffe-:-ent
  types of maize.   Each Indian tribe developed its o&n types and
  strairls, and preserved them, or modified them.
4. Their selections: iQour corn,
  (chicha),               popcorn, sweet corn for making beer
            ceremonial corn.  dxtreme imorcance in p:jr-ts of the
   Am icas.
   Columbus.   This shown by areas where maize grown before
           &JIDti 1  ( +Y eatherbfax, map of maize distributions).
Note areas of dense maize growing.   The areas of little or none:
  many of these, maize came in only late, 500 ALU or later.
The evrly areas of maize developmeit: in regions 0' heavy speckling.
5. jelections for pit.,ments in plant and ear: ilntlean maize, most
   prevalent.  tixamples of pigment in color: SLIDES 2, 3.
6. tixamples of ty,,es of ears:  the different races:=distinct strain.s.
   BLIDE 4.


1. Began in 1940s.  The Rockefeller Poundation-Mexican go,iernment
  con';ract to improve agriculture in Mexico. Instig-<ted, 1943.
2. The areas covered, vuri;us crop plants.
  maize,  potatoes, etc.
  Young men,          Borlag,      ?heat (green revolution),
                        VJellhousen,  whe;it and maize.
          entusiastic, energetic.
3. 'rhe maize reject: If improvement is to occur, must know what maize
  types are available.   The decision to collect maize all over MexiBo.
  The mode of collection:  10 to 15 ears from each farmer to determine
  what maize he may be growing.

Number of dollection 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.
  diversity of types.                   Much greater

5. The analysis: maize ears brought to Chapingo (Ag School, Rockefeller
  Foundation sectio > and placed on tables.
  then occurred,                   Matching of types
            lvhat appeared to be hybrids of types cle:rrly
  distinct from one another ordered.   Then,  plants grown from
  this classificltion to register comparisons and to reclassify, if
   necessary.

6. An example of this classification method and the consequences of it:
  B;IPlomero Toluque?io, Cacahuaciritle, Cbnico,
   parents. SLIDE 5.  (N              the cross of two suspected
                        ames, Palomero, local in Valley of Toluca;
   Cacahuacintle= Caca, cocoa; cintle = maize.  Maize with cocoa-like
   kernels.  Common mode of namiiLg maize races by Indians.
  Parent restriction in growth.  The nature of kernels.   The olavious
   distinctins: 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.
   by repeated selections for type.               Kept that way

    in Mexico:                The effect of this hybrid race
         as itself, and as it contributed to other mces; the
  limited distribution of its importance to races, and the significance
   of this for tracing the origin of the races.   SLID3 6   Wellhausen
  Big. 32, Cenico distribution.(Chromoso:rles and z)Verifications.

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

   l~ellhausen and colleagues.
   25 distinct races,       Extraordinary document.  Recognized
                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). Yrecolumbian exotics. 4 races
   (3). yrehistoric mixtures.  13 races
   (4). Modern incipient races (new combinations from itroductions
        of foyeigrl maize, hybridizing with indigenous maize). 4 races
   (5). Poorly defined races. 7.
          this class.         Our co:tribution to unraveling
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.


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V. THJ, bOH1
      ,> 7   'l%I'ION  O@ THti COMNIrTTEE FOR PK~L~ERVA~TION OF I ~IDIGENOL'S STHIIIidS
        -l , '1
   ,J.tdIU,b.,NRC:NAS .   1954-1955.

1.  The impression made on botanists and agricultur&sts of the Races
   of maize in Plexico study: brought attention to the diversity of
    maize types,  the effects of widely diverse germplasms from
    maize introduced crossed with maize indigenous to territory.
2. Hybrid-maize;  recognition of its limited germplasm selection and
    loss of potential germblasms through neglect to continue open
    pollinated varieties in indigenous regi.:ns.
3. Pear that this same situation would occur over the Americas with
    loss of much of its extraordinary germplasm potentions, whereby
     selectilns had been made over hundreds of centuries of selection
    for mutations of the regulatory type and the nucleotide types.
4. Comm$ttee functioning in cooperatitin with the,Rockefeller Foundation.
    Selections made all over the Americas as they wer made in Mexico.
     S%udies of races in territories followed collections in same manner.
    Publications for each region examined:
     Piexico, Guatemala and Central America; Colombia, Venezuela,
     The Caribbean Islands, Ecuador, ir'eru, Bolivia, Chile, and
     one ind?orporating Brazil, and adjacent sgrentina, Paraguay,
      and the Guianas.

5. One man 01. committee had theory about the chromosomes; their
  distinctive constitution differences according to elevations where
   races grown.  This required knowledge of chromosor;les at one stage
  in development of plant: the prophase of meiosis in "pollen mother
   cellslt where chromosome from ear parent synapsis side-b-side with
  chrojssome, 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.  Ply answer:Yes.
Winter, 1957-1958. Training program in Ag. Lch&, outskirts of Lima.
6. Following year, request to'do same in Colombia, South America.
  My answer was Yes.  Difficulties aro::e rega,ding person to trains.
  I decided, best for me to go directly to Colombia and eamine soiile
  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.S.
  Period, from deeember 1978 through January 1959.    l'llorked at
  Medellin,  whore maize grown for this study and adjacent to the
  Agr.  School,  supported by the Rockefeller Foundation.

VI. THE COLOMBIA EX.L'~~RILSC!E.

1.

Given bottles with pollen mother cells in them, collected from
individual plants of races in Ecuador, Bolivia, and Chile, that
were considered to be certai..ly indigenous to the area, not recentcvery)
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 Bogot&.   It proved to be important.

2.  (ihat my job was:  to examine the chror.osorle at the pachytene stage for
  any differences that might appear in them, pa-titularly the knobs,
  enlalsged 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,
   chrolLosomal types.    along with two other or thleee other maize


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3. The chromosomes: Illustrations.

iiiiiE5*  Morgan photo.
9:  McC. photo medium to large knobs.
   SiI3E    Kate photos; heterozygous knobs.
  UDE 10. Diagram of knob positions, potentials. Abn. 10 and B-type.
4. Mode of examinirlg material: completely random, l;lithout plan as I was
  not really interested in the job.  It was a face-saving job only.
Pick a bottle, record the chromosome c!.,nstitutiors for each plant:
   For each chromosome:
    position,       prsence or absence of a knob at knob-forming
   If present, and for e<tch homologue.
           size and shape of knob recorded.
  If any other change noted, was recorded.
5.  lifter about two weeks of intensive work (learly in morning and all day).
   noted something strange:  All plants at high elevations had the
   very same chromoso e constitution:
   homozygous,                no knobs except a small one,
           in long arm of chromoso:.ie 7.  HPLXJZ Two exceptions, and
  these proved to be very important for conclusions.
  In loser elevations, other knobs began to appe:ir.  Some were
    medium sized,
  In Ecuador,    some were large.
          at low elevation,  sever.:1 races at an incredible number
   of very large knobs.  Nearly all knob forming regions occuppied.
  Mangelsdorf theoryzreason for my being in Peru and Colombia. The
   higher the elevation,  the fewer knobs 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:
    large knobs.  The knobs,         Completely filled with very

    hodies in nuclei.     remain as distinct deep-stairiing roundi&

    marbles!       IWe nuclei looked as if they were filled with
           Obviously, Mangelsdorf theory not working.
  Began to recognize that the knobs were conservative.  Finished my
   period in Medellin and off to Bogat& to place collections on maps.
To place each collection on a map of the conntry where collected took
   a week with excellent and enthusiastic cooperation with maize
   persons in Colombia, particular@ Dave Timothy who became as
   excited as I about the results,
    the maps.               as they were developmag from
  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 Bolivja, 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:
     one type.  Centers of origin of maize development: start w th
           Its expansion,
     hybridizations.        then introductions later, then

   v/here were the centers?  If we examined maize from all over the
     Americas,  we should find these centers.
  Transmission of this concept to Gellhausen by 'timothy.  His
     enthusiastic response.  Invitation to try my theory in Mexico.


1. Summer, 1959 and winter 1959-1960 in 1$1exico,  dhapingo in summer where
    plants grown; winter in hlexico city examing collected materials.
2. The races examined:
    Collections of the 25 races described in klellhausen publication.
    collections of' some typical races from Guatemala, Honduras, El
    Salvadore, Nicarauga, Costa Rica, Panama, and the C,:rrib$ean islands
3. The blind method of examining, to avoid bias.
4. The analysis of the results.  Exciting.   Excellent confirmation of
     anticipations.   19uch of Xellhausens predictions of origins of the
     races confirmed.
5. Complexes : no knobs, small knobs, medium size kn:jb:;, and 1ar.g:: knobs
     began to fall into place plus the mintures, the introductions and
      the&E contributions within the new lot Ltions.
6. Subsequently, Langley and Kato.  Extended matt:rials of bultemala and
    the Caribbean Islands, and Central America.
7. Decision to cover the Amc?ricas from material collected. ldeeded
     people to work on the chror:loso!.;es at different loc:::tions.
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. TH.E RiLAIGH SW.;RIlW~ti.
1. Persons:  two from Brazil,  one from Argentina, one from ~~~exico.
2. In cooperation with faculty thelee and with vJilliam 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 countrii-?s and started examining
     races,  and collections made in Brazil and Venezuela to incre:2se
     materials available.

        '7    --\
UTHk R@BLUTIoNY Oa' RUSllLTS. Yti.RLY IN bPEXl~0 LIJY.
1. Pleetings each year, for about 6 weeks, to examine and disclss mat
    information collected for year,  and plan for that of coming year.
2. Gradual recognition of ia&qsae 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
    re,idy retrieval.   Some of the conclusions will follow after
    a few examoles are given of mode o1 ogeration.of this :;tdy.
R. THE OV,&&L STUDY.

1.  t/here collections made.  iuorth and South America. SLItiS 11 and 12.
2. Some examples showing how the study integrates relationships:
    Importance of special knobs with very limited distributions.
     \Jill show a few of them here to indicate metiiods used.

3.  .I!xLLiGL;1:Y :
   0).  $LIJE 13   10, long arm. positi.:n 1. Aapalote, Tepecintle.
      Luatemka hii;hlands.  Introducti,~n to highlands south.


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(2) -
   ;jLI1)ti 14. 4 shart arm. Large and Medium.  Coastal.
(`) Wi   7 short arm; Large knob. Nal-Tel, Zapalote
        , Arc in Guatemala, Venzuela. Perola, Guianas,
     *ioraima.  Panama, Coa tal Trop. I"lint-Tuson.   Trinidad.
     Cuba.
(4). SLIDB 16.  Central mesa, Mexico and So. west U.S.
   1 long arm, large and medium knob.
   of Guatemala.                Central Mesa dn highlands
            Central Mesa and north and north west (C6nico
   germplasm, originally from Palomero ToluqueZo.)  Introductions
   in Central America.

   (5). Chromosome 7 long arm. SLIDE 17.  Small chromosome.
    (6).  ;;LIJX L8.  2 short arm, small knob.
      VenEoraima.                  Guatemala to south. western
                Highlands of Guatemala into Yucatan
       Highlands of Guatemala and Central Mesa.   Central Mesa north
        through central region.   South America: iiltrocutions.

$1. GENX:HAL CONCLUSIOjl\lS,

1. The centers:   Knobless, Small knob, Large knobs, medium knob.
2. The integrations,
  introductions,   the consequences for races, the migrations, the
             the consequences .

3. The land and see travels demonstrated.
4. The anthropomorphical implications: Maya maize origins, Andean maize
   origins and timing.  Timing of introdu::ti:)ns into Andes  Mexi c 0
   for distinctive pop corn.  Venezuela much later (Colombia, adj. prob.
5. The origin of the varioLls knob types, originally: Mexican Teosinte.

I. The teosinte contribution to chromosome constitutions of maize-and
probably to its origin, and certai
early selections. YLJllJ3Y 19, 20, 2               subsequently to
The Indian trihbs as plant bree


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SLIDES

1, MAP of the Americas,  Weatherwax maize distributi:.)n in "ancient" times.
2. COLOR. Commercial maize; mosaic pericarp. Purple aleurone.
3. COLOR. Pvv.  Sector of "dark crown" and dark pigmented cob.
4, Ears of races, differences.  Mangelsdorf. Fig. 9.1
5. Ears, Wellhausen Fig. 36. Palomero Toluqueiio, Cacahuacintle, Cdnico
                    and hybrid of parents.

6. MAP, Iw'ellhausen Fig.  32. Distribution of C6nico in Mexico.
7. Pachytene chromosomes. Morgan photo.
8.       11               II         .  McC photo.
9. "               II         . Kato photos. Heterozygous knobs.
10. DI.&RU~, knob locatiins, 10 chromosor,les of maize.  EdtO.
11. MAP. Collections made in North America.
12. tl . Collections made in South America.
13. " . Distribution of 10 long arm small knob, position 1.
14. ll . 3 1,           If  4 short arm, large and medium knobs.
15. " .          II           11   7 short arm, large knob.
16. " .         11           II   1, long arm, large and medium knobs.
17. It .         tt           II   7 long arm, small knob.
18. ' .         II           II   2 short arm, small kl:ob.

lg. MAP. Mexican states. Wellhausen
20. Photo of Teosinte. Mangelsdorf Figure 3.4.  Chalco Teosinte
21. Ears, Maize inbred x teosinte with parents.


Chromosome 4 Short Arm
A Large knob
o Medium knob

&Large and medium knob in same CO

llection

Chromosome 10 Long Arm
   Position-l
0 Small Knob

S Plus B-trne Chromosome

A Plus B-type Chromosome and Abnormal-10 -Z@

A Plus Abnormal-10


I

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             -.- ,.,_.

6      i

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      , :\

,   -;""--.L . . . . ..." _......, j
         :

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!    9


r-J'-' ----g--.--- --.-.______._ !- .-.- -.-.+L"-- &

Chromosome 1 Long Arm
A Large knob                  : .,
o Medium knob              ', ,I
                          ` I'   i& 4 J
                                 ..s-
.'P Large and medium knob in same collection


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                       .u

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)  --~7-. . . . . . . i . .._.-_  j     !..........-?(    +..\/-.-,"4Y \ &