Hayes and Garber - Cucurbit Breeding

DEFINITIONS 1
Acquired Character. A modification of bodily structure, function,
or habit which is impressed on the organism in the course of individual life.
Aleurone. The outermost layer of the endosperm in cereals, when
it is rich in gluten.
Allelomorph. One of a pair of contrasted characters which are alternative
to each other in Mendelian inheritance. Often used, but with doubtful
propriety, as a synonym for gene, factor, or determiner.
Allelomorphism. A relation between two characters, such that the
determiners of both do not enter the same gamete but are separated into
sister gametes.
Alternative Inheritance. A distribution of contrasting parental or
ancestral characters among offspring or descendants, such that the individuals
exhibit one or other of the characters in question, combinations or
blends of these characters being absent or exceptional.
Anthesis. The period or act of flowering.
Awn. A bristle-shaped elongated appendage or extension, to a glume,
akene, anther, etc.
Barbed. Furnished with rigid points or short bristles, usually reflexed.
Biotype. A group of individuals all of which have the same genotype.
Bran. The coat of the caryopsis, consisting of pericarp and seed-coat
united.
Caryopsis.
A one-seeded dry fruit with the thin pericarp adherent to the
seed, as in most grasses.
Centgener. Originally used by W. M. Hays, at the Minnesota Station,
to refer to a 100-plant plot in which each seed was planted a certain distance
from each other seed.
Chaff. The floral parts of cereals, generally separated from the grain in
thrashing or winnowing.
Chimera. An association of tissues of different parental origin arid genetic
constitution in the same part of a plant.
Chromosome hypothesis. The hypothesis advanced by Morgan in which
factors are arranged in the chromosomes.
Class. In genetics a group that includes variates of similar magnitude.
Clone. A group of individuals produced from a single original individual
by some process of asexual reproduction, such as division, budding, slipping,
grafting, parthenogenesis (when unaccompanied by a reduction of the
chromosomes), etc.
Coefficient of Variability. A relative index of variation obtained by
expressing the standard deviation in percentage of the mean.
Coupling. Such a relation between the genes of two unit-characters
that they have a more or less marked tendency to be included in the same
gamete when the individual is heterozygous for both of the genes in question.
Many of the genetic definitions are taken from Shull (1915), Babcock
1
and Clausen (1918) or others. Ball and Piper's (1916) papers on terminology
have been used for agronomical terms.
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