Breeding for Grain Quality Traits: The challenges of measuring phenotypes and identifying genotypes. Glossary

alleles

One of the different forms of a gene that can exist at a single locus. A single allele for each locus is inherited separately from each parent.

calibration

The process of determining the crop nutrient requirement at different soil test values.

cross-pollination

The transfer of pollen from an anther of the flower of one plant to a stigma of the flower of another plant.

crossing

The deliberate mating of two parental types of organisms in genetic analysis.

DNA

(deoxyribonucleic acid) The molecule that encodes genetic information. DNA is a double-stranded molecule held together by weak bonds between base pairs of nucleotides. It is the fundamental substance of which genes are composed.

dominant

The allele that is expressed in a heterozygous organism.

electrophoresis

A technique which uses electricity to separate molecule fragments according to size so they can be studied.

environment

The combinations of all the conditions external to the genome that potentially affect gene expression.

enzyme

A protein that catalyzes, or speeds up, a specific biochemical reaction without changing the nature of the reaction.

fertilization

The act or process of initiating biological reproduction by pollination.

gene

The fundamental unit of heredity that carries genetic information from one generation to the next. A gene is an ordered sequence of nucleotides located on a particular position on a particular chromosome that encodes a specific functional protein.

genes

The fundamental unit of heredity that carries genetic information from one generation to the next. A gene is an ordered sequence of nucleotides located on a particular position on a particular chromosome that encodes a specific functional protein.

genetics

The branch of biology that deals with heredity, especially the mechanisms of hereditary transmission and the variation of inherited characteristics among similar or related organisms.

genotype

The allelic composition of a cell or organism.

genotypes

The allelic composition of cells or organisms.

heterozygous

An organism that has two different alleles at one or more locations on a chromosome.

homozygous

An organism that has two identical alleles at one or more locations on a chromosome. Inbred lines are homozygous at many of their gene loci.

hybrid

An individual produced by crossing two parents of different genotypes.

hybrids

Individuals produced by crossing two parents of different genotypes.

line

Plants within a species that have the same genetic composition and are genetically pure, (i.e., inbred line). Lines are typically not agronomically competitive and are used only in plant breeding.

lines

Plants within a species that have the same genetic composition and are genetically pure, (i.e., inbred line). Lines are typically not agronomically competitive and are used only in plant breeding.

pathway

A sequence of interconnecting enzyme reactions.

PCR

(polymerase chain reaction) A method for replicating a particular sequence of DNA in vitro. Used to generate greater amounts of DNA for analysis or to determine if a particular sequence exists.

perfect

A flower that has both functioning pistils and stamens.

phenotypes

The observable physical characteristics of an organism that are determined by a combination of the genetic composition (genotype) and the environment of the individual.

phosphorus

An essential chemical element for biological life.

pollen

Dust-like material produced by the anther (male reproductive structure) that is composed of pollen grains (microgametophytes) which carry the male gametes of seed plants; important in fertilization.

progeny

The offspring of an organism.

protein

A large molecule composed of one or more chains of amino acids in a specific order. Proteins are necessary for the structure, function, and regulation of an organism's cells, tissues, and organs. Each protein has a unique function determined by its shape.

proteins

Large molecules composed of one or more chains of amino acids in a specific order. Proteins are necessary for the structure, function, and regulation of the organism's cells, tissues, and organs. Each protein has a unique function determined by its shape.

recessive

A trait that will not be expressed unless there are two copies of the gene allele present in an organism.

recessive allele

An allele whose phenotype is not expressed in a heterozygote.

seed

Ripened fertilized ovule of a flowering plant that contains an embryo and normally capable of germination.

selection

A natural or artificial process that favors or induces survival and perpetuation of one kind of organism over others that die or fail to produce offspring.

solution

A liquid matrix where a solute has been dissolved in a solvent.

species

A fundamental category of taxonomic classification, ranking below a genus or subgenus and consisting of related organisms capable of interbreeding.

starch

Plant storage form of carbohydrate.

trait

The characteristic that results from an expressing gene(s). Ex. Upright leaves, drought tolerance, Bt resistance. A trait can be influenced by the environment.

variety

Crop plants within a species that have the same genetic composition. Because plants in a variety are usually heterozygous, their offspring will not remain genetically pure (i.e., corn hybrid varieties).