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JOMAl OF AGRICtlLTlAllSEARCH 



Vol. XIX Washington, D. C, April i, 1920 No. i 



A TEOSINTE-MAIZE HYBRID 



By G. N. COLUNS, Botanist, and J. H. Kempton, Assistant, Acclimitization and Adap- 

 tation of Crop Plants and Cotton Breeding Investigations, Bureau of Plant Industry, 

 United States Department of Agriculture 



INTRODUCTION 



The only plant which has been considered as an ancestor of our culti- 

 vated varieties of maize is teosinte {Euchlaena mexicana Schrad.) . Although 

 placed in a different genus and separated by pronounced morphological 

 differences, teosinte hybridizes freely with maize. In Mexico, where teo- 

 sinte is native, both teosinte and maize frequently show contamination. 

 Dilute maize hybrids are of such general occurrence in teosinte that it is 

 difficult to decide whether the various forms of teosinte have all descended 

 from one or more wild species. 



In attempting to determine more definitely the relation of teosinte to 

 the origin of maize, it is important to know something of the mode of 

 inheritance of the characters which separate the two genera. The follow- 

 ing paper is a study of the behavior of a number of the more sharply con- 

 trasted characters in the second generation of a hybrid between Florida 

 teosinte and a diminutive variety of maize known as Tom Thumb pop 

 corn. This variety of maize was chosen on account of its very short sea- 

 son and the large number of characters in which it contrasts sharply 

 with teosinte. 



The name Florida teosinte is applied to the variety cultivated for forage 

 in the southern part of the United States. This variety shows less evidence 

 of contamination with maize than any other form that has come under our 

 observation, and for this reason it was chosen for these experiments. 

 It is not known how this plant reached Florida. What appears to be 

 the same variety has been obtained from Tampico and Monterey, Mexico, 

 but whether it is native in Mexico has not yet been determined. Seed 

 of the Florida variety has found its way to many tropical countries, 

 and it may have been introduced into eastern Mexico, either directly or 

 indirectly, from Florida. Teosinte is wild in western Mexico; but none 

 of the forms known from that side of the country can with any assurance 



be referred to the same variety, or even to the same species as the Florida 



Oi plant. 



T— 1 Journal of Agricultural Research, Vol. XIX, No. i 



K -^ Washington, D. C. Apr. i, 1920 



__ tu Key No. G-187 



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