inheritance of the crinkly, ramose, and 
BRACHYTIC CHARACTERS OF MAIZE IN HYBRIDS 
WITH TEOSINTE 1 
By J. H. Kempton 
Assistant Plant Breeder, Office of Biophysical Investigations, Bureau of Plant Industry, 
United States Department of Agriculture 
INTRODUCTION 
To be of maximum efficiency, plant breeding must deal with all existing 
wild relatives of the plant being bred, for it is only in this way that inves¬ 
tigators can take advantage of special characteristics acquired through 
agfes 6f evolutionary progress. Zea is a monotypic genus, and its nearest 
WM relatives are the two species of large Mexican grasses, Euchlaena 
mexicafid and Euchlaena perennis , commonly known as teosinte. As a 
first step in ascertaining the possibilities of combining the desirable 
characters of maize and teosinte it is essential to determine the hered¬ 
itary behavior of hybrids between them. Progress in this direction was 
imported by Collins and Kempton in the analysis of a hybrid between 
Tom Thumb pop corn and Euchlaena mexicana (5). 2 In this hybrid 
there was seemingly complete blending of maize and teosinte characters; 
it became bf interest, therefore, to analyze the behavior of some of the 
more strictly Mendelian variations of maize in hybrids with teosinte. 
The present paper reports the inheritance of three striking Mendelian 
characters of maize, crinkly, ramose and brachytic, in hybrids with the 
anfifed ; teosinte, Euchlaena mexicana. The inheritance of these three 
variations in maize hybrids is now fairly well understood, all three 
behaving as simple, Mendelian characters recessive to the normal form. 
The great variability of maize has become a byword. Each year 
scesi the discovery of a new series of true breeding teratological forms, 
embracing almost every part of the plant, leading to the belief that the 
trinriber iff different Sorts is infinite. In fact, so numerous are abnormal 
foiihs' that improvement in maize has become centered largely on the 
problem of eliminating deleterious mutations from existing varieties. 
In view of thi^ abundance of variations in maize it seems rather Sur- 
prising that its nearest wild relative, Euchlaena mexicana , is unusually 
free from tntedtteeding abnormal variations. Although more self- 
fertilization probably occurs in Euchlaena than in maize, there is enough 
cross-fertilization to permit degenerative recessive variations to survive 
as heterozygotes, so that the difference in stability hardly can be ascribed 
,to the relatively greater homozygosity of Euchlaena. 
Crosses between Florida teosinte, Euchlaena mexicana, and most of 
the well-known Mendelian variations of maize are being made as op¬ 
portunity offers, as well as crosses between these variations and the 
perennial species Euchlaena perennis. The two species of Euchlaena 
seem to react differently in hybrids with maize, and the first generation 
T t ; 1 .1 ..... 1 ^ 
1 Received for publication Sept. 8,1923. 
, ^Reference is made by number (italic) to " Literature cited," p. 596. 
Journal of Agricultural Research, 
Washington, D. C. 
Vol. XXVII, No. 8 
Feb. S3,19*4 
Key No. G-363 
74027—24-2 
(537) 
