UL 
BOTANICAL MUSEUM LEAFLETS 
HARVARD UNIVERSITY 
CamBripcr, Massacuusetts, JuNE 30, 1964 Vo. 20, No. 9 
TRIPSACUM AS A POSSIBLE 
AMPHIDIPLOID OF WILD MAIZE 
AND MANISURIS 
BY 
Watton C. Gatrnat!, Ragu 8. K. Cuacanti’ 
AND Fioyp D. Hacer® 
AN understanding of the origin and evolution of Tripsa- 
cum is important not only from the standpoint of theo- 
retical cytogenetics but also because of the past and 
possible future contributions of this genus to the im- 
provement of maize, the basic food plant of this hemi- 
sphere (Mangelsdorf, 1961). 
Tripsacum has previously been considered to represent 
the product of collateral evolution with maize with both 
genera stemming from an ancient common ancestor. 
According to this view, the so-called diploid 'Tripsacum 
with 18 pairs of chromosomes is actually a polyploid spe- 
cies with a basic number of nine pairs. There is cytolo- 
gical evidence consistent with this view (Anderson, 1944; 
Randolph, 1955). 
‘Research Associate and 7 Research Fellow at the Bussey Institution 
(mailing address: Botanical Museum of Harvard University, Cam- 
bridge, Mass. 02138). 
>The embryo culture work which made these studies possible was 
accomplished by Dr. Hager as his tribute to the memory of the late 
Professor Edward Murray East. Dr. Hager notes that ‘‘It is satisfy- 
ing that from the helpfulness he offered some 30 years ago in my lily 
work at the historic Bussey Institution, there developed a skill which 
made possible a contribution in a field that meant a great deal to him.’’ 
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