HERITABLE CHARACTERS OF MAIZE 
V. ADHERENCE 
J. H. KEMPTON 
Bureau of Plant Industry, U. S. Department of Agriculture 
DHERENCE is a variation in 
which the leaves, bracts and in- 
florescences coalesce. Any or 
all of these organs may adhere to one 
another to a varying extent. In ex- 
treme cases the upper leaves and ter- 
minal inflorescences are so firmly com- 
pacted into a hardened mass that the 
parts can not be separated. In less ex- 
treme cases the adhering organs sepa- 
rate naturally with the pressure of the 
growing parts. Frequently the leaves 
and even husks adhere so firmly to 
other organs that they are ruptured by 
the force of the elongating plant or 
shoot and such plants have a charac- 
teristic ragged appearance. 
In some cases the variation is exhib- 
ited in seedlings but unless the leaves 
of the young plants adhere so firmly as 
to prevent further growth, the plants 
recover and apparently grow normally 
until the ear bearing node is reached, 
at which stage their adherent nature 
is manifested again. (See Fig. 16.) 
The firm union of the upper leaves 
prevents proper elongation, causing 
startling contortions of the confined 
culms. (See Fig. 18.) When the ear 
is included in the adhering mass the 
enclosing husks also are united and 
unless they are opened artificially the 
silks cannot be exserted. 
In many cases the growing ear, held 
firmly at the upper end, is forced into 
contortions similar to those of the culm. 
(See Fig. 19.) This purely mechanical 
inhibition of elongation reduces the 
length of the affected internodes as well 
as the ear and where the variation is 
pronounced, seed rarely is obtained. 
The tassels of such plants are greatly 
altered, being compressed into a solid 
structure, never expanding into the fa- 
miliar branched panicle. Insuch an ad- 
herent inflorescence pollen is shed only 
from the spikelets of the lower or outer 
branches and not even from these un- 
less the inflorescence has been artifi- 
cially liberated from the confining mass 
of sheaths and blades. In less extreme 
cases the tip of the central spike will be 
exserted naturally, producing a small 
quantity of pollen and it is from such 
plants as these that the variation is 
propagated most readily. 
The glumes of the staminate spike- 
lets often are reduced greatly in length 
and altered in appearance resembling 
the hardened glumes of the ear. Not 
infrequently they have been so reduced 
in length that the anthers protrude 
from the unopened spikelets. The 
firmly compacted male inflorescence 
with the altered glumes strongly sug- 
gests the cob of ear, but when such an 
inflorescence is sectioned there is no 
evidence of fasciation and the interior 
branches and central spike are found 
to have developed spikelets. 
BREEDING MUST ELIMINATE ADHERENT 
PLANTS 
The undesirability and entire worth- 
lessness of adherent plants needs no 
emphasis and the variation takes its 
place with the ever increasing list of 
detrimental recessive abnormalities 
which breeding must eliminate. 
The adherent variation was found 
in the second generation of a hybrid 
between the Boone County white 
variety and brachytic.! Two plants of 
a brachytic progeny were crossed with 
two plants of an inbred strain of Boone. 
In each cross brachytic plants were 
used as the female parents. The plants 
of the first generations were all normal 
and of greatly increased vigor. 
Several self-pollinated ears were ob- 
tained from both hybrids but only three 
‘Kempton, J. H. A Brachytic Variation in Maize. U.S. Dept. of Agr. Bull. 925. Feb. 1921. 
Shefe 
