Glossary

Term

Definition

Alleles Alternative forms of a gene that can occupy a particular position (locus) on a pair of chromosomes
Anther culture A technique in which haploid plants are obtained by growing anthers by tissue culture
Anthers The structures which produce pollen in a flower
Awns Slender bristle-like appendages that form on the heads of some cereal crops.
Breeding lines A group of identical pure-breeding plants used in a breeding program that have a unique and distinctive genotype.
Chromosomes Thread-like structures of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes. They occur in pairs in normal body cells.
Clones Organisms that are exact genetic copies. Every single piece of DNA is identical.
Colchicine A chemical, that when applied to plant roots, results in a doubling of the number of chromosomes in the cells of the plant
Control A treatment group in a trial that is used as the basis of comparison between all other treatments.
Cross pollination When pollen from flowers on a different plant pollinates the stigmas of a flower
Crown rot A fungal disease of cereal crops which results in significant grain yield losses.
Dicots Plants that have two cotyledons in the seed. Dicotyledons have branched veins, flower parts in multiples of four or five and a taproot system.
Diploid Containing two complete sets of chromosomes, one from each parent.
DNA Deoxyribonucleic acid. The material which the main constituent of chromosomes. It is the carrier of genetic information
Dormancy The situation where seeds do not germinate despite having favourable conditions to do so. This is most commonly due to them having hard seeds coats, chemical inhibitors in the seed coat or the need to experience particular environmental conditions prior to germination.
Double haploid A genotype formed when haploid cells undergo chromosome doubling. Artificial production of doubled haploids is important in plant breeding.
Durum A variety of wheat that has a higher protein and gluten content than other kinds of wheat and that is most often used to make pasta.
Emasculation Removal of the male reproductive structures in a flower
Embryo rescue Surgical removal of the developing embryo in a pollinated flower. It is then grown on to produce a plant using tissue culture
Endemic Growing or existing in a particular place or region
F1 hybrids The first generation of plants produced when two pure breeding lines of a plant are crossed
F2 hybrids Plants produced by crossing two distinct F1 hybrid plants
Fertilisation The joining together of a pollen cell and an ovule to form an embryo
Genes Hereditary units consisting of a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic in an organism.
Genotype The genetic composition of an organism
Genotype The inheritable genetic information carried by an organism.
Germplasm Living tissue from which new plants can be grown. It can be a seed or another plant part – a leaf, a piece of stem, pollen or even just a few cells that can be grown into a whole plant.
Gluten A protein composite found in wheat and related grains, including barley and rye. It gives elasticity to dough, helping it rise and keep its shape.
Haploid A cell that contains one complete set of chromosomes. Gametes (sex cells) are haploid cells that are produced by meiosis.
Heterozygous Having different alleles at a particular gene locus on a pair of chromosomes
Homozygous Having the same alleles at a particular gene locus on a pair of chromosomes
Hybrid plants Plants produced by crossing two different varieties, species or genera of plants
Hybridisation The process of crossing plants or animals of different species or varieties to produce a hybrid.
In-breeding The production of offspring from the breeding of individual plants or animals that are closely related genetically.
Incompatibility When the pollen from a particular plant is unable to fertilise the ovules of another.
Inoculum A source of pathogenic microbes in a crop (such as left over stubble from a previous crop).
Leaf rust A fungal disease (Puccinia triticina) of wheat, barley and rye that is characterised by the presence of orange-brown groups of spores on the stems, leaves and grains. Also known as brown rust.
Lodging When the stems of a crop plant (usually a cereal) fall over and/or break. This interferes with the processes within the plant and makes harvesting difficult.
Marker assisted selection A method of selecting desirable individuals in a breeding program based on DNA molecular marker patterns instead of growing the plants and observing their characteristics.
Mass selection A plant breeding technique which involves selecting superior plants from a population, growing a new generation from their seed, selecting the superior plants from the second generation and growing them on again. The process is simply continued for many generations.
Meristems Regions in a plant that consist of actively growing cells that can form new tissues.
Molecular markers Fragments of DNA which are associated with a particular gene. By confirming that the molecular marker is present plant breeders can be certain that the gene is present without needing to grow the plant first.
Monocots Plants having a single cotyledon (seed leaf) in the seed. Monocotyledons have leaves with parallel veins, flower parts in multiples of three, and fibrous root systems.
Mutation The changing of the structure of a gene which results in the gene being expressed differently in the next generation
Nematodes A group of unsegmented roundworms, some of which live in the soil and attack the roots of plants.
Ovules The female sex cells of a plant
Pathogen An organism that causes diseases in plants and animals.
Phenotype The appearance and productive characteristics of an organism
Physiology The study of the normal functions of living organisms and their parts.
Plant pathologist A scientist who studies diseases in plants.
Pollen The male sex cells of plants
Pollination The transfer of pollen from anthers to the stigma of a flower
Pure breeding Plants in which sexual reproduction produces offspring with inherited traits identical to those of the parents. The organisms are homozygous for the characteristics under consideration.
Pure lines Populations of plants that are pure breeding
Randomisation Selecting the treatment groups in a trial in a random manner so that there is no bias involved in their selection.
Replication Repeating experimental treatments on more than one group of plants or animals.
Resistance The ability of a pest organism (insect, microbe, weed) to survive the application of a particular chemical that would normally kill it.
Selective breeding The process by which humans breed other animals and plants for particular traits that they have chosen. Also known as artificial selection.
Self pollination When pollen from flowers on the same plant pollinates the stigmas (and fertilises the ovules) of a flower. Also known as selfing.
Spores The reproductive structures of fungi and some bacteria.
Standard deviation A statistical measurement of how much the members of a group differ from the mean value for that group.
Standardisation Ensuring that all variables in a trial are the same for each treatment group EXCEPT the one being investigated.
Stem rust A fungal disease (Puccinia graminis) of wheat and barley that is characterised by the presence of reddish-brown groups of spores on the stems and leaf sheaths. Also known as black rust.
Stigmas The female structure which receive the pollen at the time of pollination
Stomata Tiny openings in the epidermis of a plant, through which gases and water vapour pass.
Stripe rust A fungal disease (Puccinia graminis) of wheat and barley that is characterised by the presence of reddish-brown groups of spores on the stems and leaf sheaths. Also known as black rust.
Stubble What remains of a crop after it has been harvested.
Test of significance A statistical test that is applied to experimental data to indicate whether observed differences between treatment group results occurred because of sampling error or chance or whether they are due to the applied treatment.
Tillering The development of new stems from the base (crown) of many monocotyledonous plants.
Tissue culture A technique with which plant cells, tissues or organs are grown on artificial nutrient medium under sterile and controlled conditions. It is possible to grow a whole new plant from single cell, tissue or organ with the use of various tissue culture techniques.
Traits Distinguishing characteristics or features of a living thing.
Variability The degree of spread amongst a set of experimental data.
Virulence The ability of a micro-organism to infect a plant or animal.
Zero till The process of planting a crop into uncultivated land. Also known as direct drilling.

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