inheritance of dwarfing in maize 1 
By J. H. Kempton 
Assistant Plant Breeder , Office of Biophysical Investigatiom , Bureau of Plant Industry , 
United States Department of Agriculture 
INTRODUCTION 
There are two forms of dwarf plants in maize which seem to be in¬ 
herited as simple Mendelian characters recessive to normal stature. 
These two dwarf forms differ in most characters but are alike in that the 
great reduction in stature is brought about in each case through a reduc¬ 
tion in the length and not in the number of intemodes. One of these 
dwarfs is known simply as Dwarf G) 2 : the other has been designated 
Brachytic (7). 
The variation known as dwarf is one which has been confused until 
recently with a somewhat similar semidwarf variation now known as 
anther ear, both being andromonoecious, but that these two variations 
are wholly unrelated has been demonstrated by the Emersons (5). In 
view of their rather close resemblance, involving the same complex of 
characters, and the confusion of the two forms in earlier reports, it is not 
possible, in the absence of genetic comparisons, to state with certainty 
which of the two forms has been found by the different observers. One 
of these andromonoecious types of maize was described by Mont¬ 
gomery (9), who found it in a stock of StowelTs Evergreen sweet com. 
Other independent origins have been reported of variations very similar 
to the one designated dwarf, which seems to be one of the commonest 
major variations in maize, appearing in wholly unrelated stocks from 
widely separated localities. 
Two of our pedigreed cultures have given rise to andromonoecious 
plants of dwarfed stature. These cultures were not related, one being 
a hybrid of the hairy Mexican type, Esperanza (2), with Emerson’s 
liguleless strain (4), and the other a variety of maize originally grown by 
the Pawnee Indians, the seed stock of which was received from Mr. M. R. 
Gilmore. In this latter case the variations appeared in the fourth gener¬ 
ation of consecutive inbreeding. These variations were dissimilar in 
size, that from the Pawnee variety being somewhat variable in height 
but obviously larger than that from the Esperanza-liguleless hybrid. 
Comparisons were made between these two dwarf forms and the 
variations described and named by Emerson, anther ear, and dwarf, 
seed of which was kindly furnished by Professor Emerson. The strain 
derived from the Esperanza resembles Emerson’s dwarf while the dwarf 
from Pawnee more closely resembles the anther ear, but both variations 
with respect to stature occupy an intermediate position between anther 
ear and dwarf, probably due to the height characteristics of their parental 
strains. The tallest of the dwarf plants, however, are less than half the 
height of their normal sibs, and while variation exists among them they 
never approach in height plants of normal stature (PI. 1). Without 
1 Accepted for publication May 2,1923. 
1 Reference is made by number (italic) to “literature cited," p. 320-321. 
Journal of Agricultural Research, 
Washington, D. C. 
afz 
(297) 
Vol. XXV, No. 1 
Aug. 18,1923 
Key No. G-325 
