glossary of terms

To find a particular term, click on one of the following letters:

Acclimatization

The process by which a population adjusts and modifies to adapt to the changing environment or stress conditions.

Addition polymerization

The stepwise addition of a simple repeated unit.

Additives

Materials that are added to a polymer to produce a desired change in material properties or characteristics.

Allogamy

Cross-pollination or pollination of a flower with the pollen produced on the flower of another plant.

Anemophily

A type of pollination where pollen is dispersed by the wind.

Angiosperm

Seed producing plants, characterised by having flowers with seeds formed inside an ovary that have endosperm within them. These plants produce fruit that contain seeds.

ANOVA

Meaning analysis of variance. It is a statistical procedure used to test the degree to which two or more groups vary or differ in an experiment. In most experiments, a great deal of variance (or difference) usually indicates that there was a significant finding from the research.

Anther

Part of a stamen (male reproductive organ) which has a stalk called a filament to which is attached the anther which produces and contains pollen in it.

Anthesis

The period when anthers dehisce and pollen is dispersed, and the flower is fully open and flowering.

Apomixis

A form of sexual reproduction in which sexual organs or related structures take part but seed is formed without the union of male and female gametes.

Asexual reproduction

Reproduction that does not involve union of gametes, and may be through vegetative parts or seed like structures produced through apomixes.

Artificial or synthetic seed

Somatic embryos/shoot buds encapsulated in synthetic seed coat which is capable of producing normal plant.

Autogamy

Self-fertilization where egg produced in the ovary of a plant unites with sperm produced on the same flower.

Backcross

The cross of F1 hybrid with either of the parents.

Blank Pollination

When instead of using pollen for pollination only powder resembling the pollen is introduced in the pollination bag. Often it is used as a test of the pollinating worker and also quality of bag.

Breeders

Scientists who breed new breeds of animals or varieties of plants using principles of genetics. They are thus known as animal breeders and plant breeders.

Breeder seed

The seed or any other propagating material multiplied by originating plant breeder or institute under strict purity standards and is source for producing foundation seed.

Breeding

The art and science of changing and improving inherited properties of living organisms.

Bunches

A cluster of fruit e.g. in oil palm, grapes, bananas.

Burst Strength

The pressure required to rupture a material.

Calendaring

A finishing process used on fabric; the fabric is passed between rollers at high temperatures and pressures to produce a smooth surface.

Carding

A mechanical process that disentangles, cleans and intermixes fibers to produce a continuous web.

Carpel

The female reproductive part of the flower. It produces ovules in its basal part called ovary that develop into seeds and the ovary with seeds into the fruit.

Cement sacks

Paper bags made from 2 or 3 plies of Kraft paper.

Cereal

A type of grass belonging to the monocot family, Poaceae, grown for the edible components of its grain which is a single seeded fruit called caryopsis, and is composed of the endosperm, germ, and bran.

Condensation polymerization

The combination of functional molecules, leading to the formation of a polymer with the liberation of simple by-products, usually water.

Contamination rates

The extent of outcrossed seeds produced by pollination with foreign pollen.

Copolymers

Polymers with repeating molecular units from at least two different monomers.

Cultivar

A synonym and international equivalent of variety which usually specifies a cultivated variety.

Density

Mass per unit volume of a material at 73°F (23°C).

Differential Scanning Caolorimitry

A thermo-analytical technique in which the difference in the amount of heat required to increase the temperature of a sample and reference is measured as a function of temperature.

Diploid

Having two haploid sets of homologous chromosomes.

Distributor

A person or firm engaged in general distribution or marketing of some class of products or goods. Wholesale distributors have rights to market within a given territory and supply products to retailers.

Dry Laid

A non woven fabric production method using dry fibre. Can apply to carded webs and air blown random webs.

DNA

Deoxyribonucleic acid which is the building block of genes and thus represents the hereditary material. It is long molecule made of nucleotides whose sequence determines the sequence of amino acids in the proteins. The genetic information in the gene is stored in DNA in the form of code of nucleotides.

Domestication

The process of bringing wild plants under cultivation to produce crops under human care.

Double Fertilization

The union of two male gametes (sperms) simultaneously with the cells of embryo sac. One unites with the egg cell to produce zygote and the other unites with two polar nuclei to form endosperm. The first union is called fertilization and the later union is known as double fertilization.

Doubled haploid (DH)

An individual produced by doubling its gametic chromosome number.

Durability

The relative term for the resistance of a material to loss of physical properties or appearance as a result of wear or dynamic operation. In plants durability may refer to retention of disease resistance ability for a longer period of time.

duraweb®

Our unique non woven material that is strong against abrasion and tearing, while being breathable and halting unwanted pollen.

duraweld®

Our ultra-strong welding process that creates robust pollen proof seals. The material is fused together, avoiding both the holes and risk of separation which effect inferior stitched or glued products.

duratrace®

Our quality control system. Quality assurance also comes through complete traceability and process control, extending from material manufacture to packing procedures.

Emasculation

Manual or by other means the removal of the anthers from a flower to make it ineffective for producing pollen.

Embryo

It is rudimentary plant within the seed which arises from the zygote after fertilization of male and female gametes.

Embryo sac

The female gametophyte which has eight nuclei that after fertilization and double fertilizer develop into seed.

Endosperm

A tissue within seeds of flowering plants. It is a triploid (3n) tissue that develops by triple fusion of sperm nucleus with two polar nuclei in the embryo sac. Endosperm is the storehouse of carbohydrates, oils and proteins.

Entomophily

A type of pollination where the pollen is dispersed by insects.

Fertilisation

The union of female egg and male gamete to form zygote.

Forestry

The science or practice of planting, managing and caring for forests.

Fruit

A part of a flowering plant that derives from specific tissues of the flower, one or more ovaries, and in some cases accessory tissues. Fruits are the means by which these plants disseminate seeds.

Full-sib

Members of the progeny with both parents common.

Gamete

Cell for fertilization produced through meiosis, eg ovum and pollen, specialized for sexual reproduction, gametes have half the normal number of chromosomes so when two combine the resulting embryo has a normal compliment of chromosomes in each cell.

Gene

A segment of DNA molecule that determines the sequence of amino acids in the polypeptide and thus controls the development of a character.

Gene bank

Collection and conservation of germplasm of a species either in the native ecosystem or in the form of genetic collections away from their natural habitat.

Gene pool

Sum total of genes present in an intermating population.

Genome

A set of chromosomes that represents the haploid chromosome number within the gametes of a diploid species. The complete set of genes or genetic material present in a cell or organism.

Genetic Integrity

Seeds and seed bunches that have not been contaminated by unintended pollen and are therefore transmitting the intended traits into the next generation.

Germinated seeds

Seeds that have begun to sprout and grow.

Germplasm

The hereditary material of an organism which is transmitted to next generation.

Glassine

A very thin and smooth paper that is air and water resistant, manufactured by super-calendering. It is naturally translucent.

Graft-copolymer

A branched-chain structure that has side chains composed of one type of monomer unit attached to the backbone or main chain from another monomer unit.

Green revolution

The term used to characterize phenomenal increase in yield of wheat and rice through enhancement of inherent potential and input resources especially in the developing countries. Often associated with the work of Norman Borlaug in the 1960s and 1970s.

Gusset

A usually diamond-shaped or triangular insert in a seam to provide expansion or reinforcement. Found on 3D pollination bags.

Haploid

An individual with a single set of chromosomes (n), i.e. the gametic number of chromosomes which typically includes one of each pair of homologous chromosomes.

Harvest index

The ratio of economic yield to biological yield of a crop.

Heritability

The part of variation among individuals which is controlled by genetic factors and transmitted to progeny. The proportion of genetic variation to the total is broad sense heritability whereas the ratio of additive genetic variation to the total variation is narrow-sense heritability.

Heterosis

The increase or decrease of F hybrid over parents for any trait.

Homopolymers

Polymers which are made up of one single repeated basic unit or (mono)mer.

Hops

The female flower of the Hop plant, Humulus lupulus used as a flavouring and stabilising agent in beer.

Hybrid

The first generation offspring of a cross between genetically different plants.

Hydrophily

A type of pollination where the pollen is distributed by water.

Inbred line

The homozygous or pure breeding line produced by continuous self-fertilization or inbreeding in normally cross-pollinated crops.

Inbreeding

A system where genetically related individuals are mated with each other. Self-pollination is an extreme form of inbreeding.

Inbreeding depression

The reduction in vigour and performance for other characters of the progeny produced through inbreeding.

Introgression

Transfer of a gene or few genes from a wild relative to cultivated species.

Inflorescence

A is the mode of development and arrangement of cluster or group of flowers on an axis that is composed of a main branch or a complicated arrangement of branches.

Jatropha

A genus of flowering plants in the spurge family, Euphorbiaceae. Jatropha curcas of this genus is sometimes thought of as one of the best candidates for future biodiesel production.

Kraft paper

Produced by the chemical treatment of wood chips with a mixture of sodium hydroxide and sodium sulfide; this breaks the bonds that link lignin to the cellulose. Kraft paper is stronger and more porous, with higher elasticity and tear strength compared to normal paper. It is darker than most papers due to a lower level of processing.

Kernel

A single seeded fruit or grain, especially of corn or wheat.

Laminate

A product made of multiple layers, which are strongly bonded together often by glue and high pressure.

Light transmission

The amount of light that penetrates the material.

Male sterility

The condition where pollen is not produced or is non-functional for pollination.

Micron

A micrometre or micron (symbol µm) is one millionth of a metre, or equivalently one thousandth of a millimetre. It can be written in scientific notation as 1×10−6 m, meaning 1/1 000 000 m.

Micro-climate

A local atmospheric zone where the climate differs from the surrounding area.

Monoeocy

Having male and female flowers born separately on the same plant, e.g. maize.

Monomers

The singular molecular unit from which polymers are prepared.

Mutation

A sudden heritable change in an organism. It may involve change in a single gene or part of chromosome.

Non-woven fabric

A fabric-like material made from long fibers, bonded together by chemical, mechanical, heat or solvent treatment.

Null hypothesis

A statistical hypothesis of no differences between observed and expected, which is used to perform test of significance.

Outcrossing

When pollen falling on stigma of a flower comes from flowers born on different plants. It can occur naturally or artificially by pollinating with unrelated pollen that introduces unrelated genetic material into a breeding line to increase genetic diversity.

Ovule

Ovule means small egg. In plants it is a structure that gives rise to and contains the female reproductive cells. After fertilization, the ovule develops into a seed. Thus ovule is precursor of seed.

Palm Oil

An edible vegetable oil derived from the mesocarp (reddish pulp) of the fruit of the oil palms, primarily the African oil palm Elaeis guineensis, and to a lesser extent from the American oil palm Elaeis oleifera.

Paper

A thin material produced by pressing together moist fibres of cellulose derived from wood pulp and then drying them into flexible sheets.

Pedigree

A record of ancestry of an individual, family or strain.

Perfect flower

Flower possessing both essential floral parts, stamens and pistils.

Phenotype

External appearance of an organism as contrasted with its genetic make-up or genotype for a particular character.

Phloem

One of two types of transport tissue in vascular plants, xylem being the other. The basic function of phloem is to transport organic nutrients in particular sucrose.

Plant breeder

A plant scientist who uses genetic principles to breed new varieties with improved levels of desired characteristics.

Plant breeders’ rights

The statutory provisions that empower a breeder or an originating institute of a variety to regulate the multiplication and marketing of seed of protected variety. Intellectual property protection for plant breeders.

Poaceae

Also known as true grasses. A large and nearly ubiquitous family of monocotyledonous flowering plants, with more than 10,000 domesticated and wild species.

Pollen collection

The act of collecting pollen from plants for a specific purpose.

Pollen grain

A fine to coarse powder produced by male parts of plants which produces male gametes (sperm cells) for fertilization leading to seed production.

Pollen vector

Pollinator, the biotic agent (vector) that moves pollen from the male anthers of a flower to the female stigma of a flower to accomplish pollination and fertilization. Usually insects, but also reptiles, birds, mammals and sundry others that routinely transport pollen and play a role in pollination.

Pollen viability

Pollen is a living biological entity. It can only pollinate a stigma if it is viable or functional, meaning actively alive. If the pollen gets too hot, cold or old then its viability may be reduced influencing its ability to fertilise and produce seed.

Pollination

Transfer of pollen from anthers to stigma.

Pollination bag

Bags made from a variety of materials, PBS uses duraweb®, designed to control plant pollination. The bag acts as a barrier to unwanted pollen directly or indirectly by agents such as insects.

Pollination control

The act of exercising control over pollination in plants with certain artificial means.

Polycross

Open pollination of a group of genotypes grown in such a fashion so as to ensure random mating. It is used in forage crops.

Polymorphism

Simultaneous occurrence of two or more distinct forms in a population. For instance within a species flowers may be in two distinct colours such as yellow or purple.

Protandy

When the stamens mature first and shed pollen, before the stigma of the same flower matures. It prevents self-pollination.

Polyploidy

An individual with more than two sets of chromosomes. This could be triploid (3 sets), hexaploid (6 sets) etc.

Polyester

A synthetic resin in which the polymer units are linked by ester groups, used chiefly to make synthetic textile fibres.

Polyethylene

The simplest and most commonly used polymer, containing simple carbon and hydrogen atoms. Its main use is for packaging and plastic carrier bags.

Polypropylene

A synthetic resin of which is a polymer of propylene. Used mainly for films, fibres, packing and reusable plastic containers. It is rugged and unusually resistant to many chemical solvents, bases and acids.

Polyester

A category of polymers, which contain an ester functional group in their main chain. There are many polyesters but the term “polyester” as a specific material most commonly refers to polyethylene terephthalate (PET). Polyesters include naturally occurring chemicals, such as in the cutin of plant cuticles, as well as synthetics through step-growth polymerization. Natural polyesters and a few synthetic ones (often made from starch) are biodegradable, but most synthetic polyesters are not. Depending on the chemical structure, polyester can be a thermoplastic or thermoset.

Polymer

The product of a reaction called polymerization, the process of connecting many (poly) single units (mers or mono-mers) to form long chain molecules of higher molecular weight.

Polymer chain

A polymer in which the monomers are bound to each other in a straight chain without any branches.

Polymerization

The process of converting a monomer or a mixture of monomers into a polymer.

Polymer Structure

A general term referring to the relative positions, arrangement in space, and freedom of motion of atoms in a polymer molecule.

Porosity

Porosity is the quality of being porous, or full of tiny holes. Porosity or void fraction is a measure of the void (i.e., “empty”) spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0 and 100%.

Protogyny

When the female part (stigma) of a flower becomes receptive first, before the shedding of pollen by anthers. It prevents self-pollination.

Pureline

The progeny of a single homozygous individual produced through self-fertilization.

Qualitative characters

Characters controlled by one or few genes with effect large enough to produce distinct classes for each genotype.

Quantitative characters

Characters which show discontinuous variation ranging from one extreme to the other, and are controlled by many genes (polygenes) with small and similar effect without forming distinct classes.

QTL

Quantitative trait locus. A segment of chromosome marked with molecular markers which has significant effect on the performance of a quantitative character.

Recombinant

An individual produced by combining genes from both of its parents and thus represents a new combination of genes.

Recycled plastic

Any plastic compound or resin that has been previously subjected to processing and use then reprocessed for a second or third time. Only thermoplastics can be recycled.

Regression

The dependence of one variable upon another and is measured by regression coefficient which gives an estimate of the number units by which dependent variable changes by one unit change of independent variable.

Regression analysis

A method of statistical analysis for estimating the relationships among variables. It includes many techniques for modeling and analyzing several variables, when the focus is on the relationship between a dependent variable and one or more independent variables.

Relative humidity

The ratio of the partial pressure of water vapour in an air-water mixture to the saturated vapour pressure of water at a prescribed temperature.

Seed

A mature fertilized plant ovule, consisting of an embryo and its food store surrounded by a protective seed coat (testa).

Seed producer

An individual, or company, that grows plants to produce seeds for commercial purposes.

Seed set

The number of ovules that successfully develop into seeds after pollination.

Segregation

The separation of homologous chromosomes, and thus alleles or different forms of a gene, during formation of gametes.

Selection

A procedure that allows some of the individual in the population to breed differentially so that the frequency of those successfully breeding increases in succeeding generations.

Selection differential

The difference between the mean of selected group of plants and the original unselected population.

Selection index

A single value obtained from linear combination of different component traits combined in such a way that selection based on selection index value maximizes the overall genetic worth of the progeny.

Selection intensity

The percentage of population which is retained through selection.

Self-incompatibility

Failure of pollen to fertilize on self-pollination but produce normal seeds on flowers of genetically different plants.

Self-pollination

The transfer of pollen from anthers to stigma of the same flower or another flower borne on the same plant. Such flowers are often bisexual or hermaphrodites having both male and female sexual parts in the same flowers. But self-pollination can also occur in plants with unisexual flowers such as maize where pollen from the tassel falls on the silk of the same plant.

Selfing Bag

Another name for a Pollination bag, a bag designed to control plant pollination.

Sexual reproduction

Reproduction involving male and female sexes to produce the seed.

Sib

The offsprings in a progeny related by parental descent. Abbreviation of sibling.

Single Nucleotide Polymorphism

A DNA sequence variation occurring commonly within a population (e.g. 1%) in which a single nucleotide — A, T, C or G — in the genome (or other shared sequence) differs between members of a biological species or paired chromosomes.

Spadix

Is a form of spike inflorescence in which the florets are densely crowded along a fleshy axis, and enclosed by one or more large, often brightly–coloured bracts called spathes.

Spathes

A sheathing bract or pair of bracts partly enclosing an inflorescence and especially a spadix on the same axis.

Specific gravity

The mass of a given volume of material at 73°F (23°C) divided by an equal volume of water at the same temperature.

Spinning

A manufacturing process for creating polymer fibers. It is a specialized form of extrusion that uses a spinneret to form multiple continuous filaments. There are many types of spinning: wet, dry, dry jet-wet, melt, gel, and electrospinning.

Spun Laid

A nonwoven fabric production method in which a polymeric melt is extruded through spinnerets to form filaments which are laid down on a moving screen.

Stamen

The male reproductive organ in a flower having a stalk called filament to which are attached pollen producing anthers.

Strobili

A structure present on many land plant, eg pine trees, species consisting of sporangia-bearing structures densely aggregated along a stem.

Stigma

The apical part of the female reproductive organ in a flower which when receptive receives the pollen during pollination process.

Style

A hollow tubular part of female reproductive organ in a flower through which pollen tube grows to reach the ovary for fertilisation.

Synthetic variety

A population produced by intermating of good combining inbred lines with subsequent maintenance by open pollination. The components of the synthetic are inbreds or clones and thus synthetic can be periodically reconstituted or syntheisized.

S.TT

A specialist tent tube product from PBS International. A cylinder provided open ended or sealed at one end. For covering a whole plant or groups of plants. 160cm x 75cm. Comes with 1 window at 30cm x 25cm.

S.PC

A specialist pollen collector product from PBS International. Designed for collecting pollen without having to open the bag, minimising the risk of contamination. The pollen can be shaken down into a plastic collection bag. Supplied flat for self assembly. 100cm (including spout) x 51cm. Comes with one window 15cm x 15cm.

S.MS

PBS International’s smallest bags, made with windowless 2D construction suitable for small individual pannicles or small plants. 12 cm x 6cm.

S.ML

PBS International’s smallest bags, made with windowless 2D construction suitable for small individual pannicles or small plants. 15cm x 7.5cm.

Tassel

The male inflorescence born on top of a maize plant.

Tassel bag

A pollination bag design to cover the tassel and collect pollen.

Tensile strength

A measure of the amount of force required to elongate the plastic by a defined amount.

Thermoplastic

A polymeric material that becomes soft and formable when heated and rigid when cooled. This process may be repeated a number of times without chemically altering the material.

Thermoset

A polymeric material that undergoes an irreversible chemical changes when cured through heat, catalysts or ultraviolet light: cross-linking prevents movement of molecular chains after curing. Once cured, the structure cannot be changed.

Top cross

The cross of inbreds, clones or other populations with a common broad based pollen parent (tester parent).

Transgenic plants

The plants modified by adding a gene from unrelated plants or organisms through special techniques of transformation, i.e. by bypassing sexual hybridization.

Transgressive segregation

The appearance of individuals in F2 of a cross which fall outside the parental range for quantitative characters.

UV absorbers

Additives which protects materials by absorbing UV radiation.

UV stable

Resistant to ultra-violet radiation in sunlight. UV light can cause non-resistant fibres or materials to fade, or become brittle. This can cause a fabric to “fall apart”.

UV stabilisers

Additive which stabilises organic materials against UV radiation.

Variation

The occurrence of differences among individuals due to genetic causes or environmental differences.

Variety

A group of similar plants within a species which are distinctly different for some structural features and performance from other varieties of the same species.

Virgin material

Any plastic compound or resin that has not been subjected to use or processing other than that required for its original manufacture.

Virulence

Capacity of a pathogen to incite disease.

Weevils

A small herbivorous beetle from the Curulionoidea superfamily. Weevils may carry pollen and  thus in controlled breeding may cause contamination.

Wet Laid

A non-woven fabric production method using modified paper making techniques, involving creating a random web of fibres by dispersion in liquid.

Woven fabric

A textile formed by weaving. It is produced on a loom, and made of many threads woven on a warp and a weft.

Xenia

The impact of the genotyope of pollen on the phenotype of the endosperm of the seed which develops after pollination. In maize, a white grained plant receiving pollen from yellow grained plant will show yellow grains on the ear-head due to xenia.

Xylem

Is one of the two types of transport tissue in vascular plants, phloem being the other. The basic function of xylem is to transport water, but it also transports some nutrients.

Yield

The quantity of produce of desired output in return for cultivation. Seed yield refers to number of seeds or weight of seeds or both. In plants it may be oil yield, fodder yield, fruit yield, fibre yield etc.

Zoophily

A type of pollination where pollen is transferred by vertebrates, particularly birds and bats.

Zygote

The cell obtained after union of male and female gametes which develops into embryo.

2D.1

Standard slim profile bag produced by PBS International. 51cm x 25.5cm with 1 window at 12cm x 12cm.

2D.2

Standard slim profile bag produced by PBS International. 63.5cm x 45cm with 1 or 2 windows at 12cm x 12cm.

2D.3

Standard slim profile bag produced by PBS International. 75cm x 51cm with 1 or 2 windows at 15cm x 15cm.

2D.4

Standard slim profile bag produced by PBS International. 91.5cm x 63.5cm with 1 or 2 windows at 30cm x 15cm on the front and 15cm x 15cm on the back.

2D.5

Standard slim profile bag produced by PBS International. 100cm x 75cm with 2 windows at 30cm x 15cm on the front and 15cm x 15cm on the back.

3D.55

Standard bag with additional gusset to provide extra capacity produced by PBS International. 55cm x 15.8 cm x 15.8cm. Comes with 1 window at 25cm x 10cm with an optional flap.

3D.65

Standard bag with additional gusset to provide extra capacity produced by PBS International. 65cm x 15.8 cm x 15.8cm. Comes with 1 window at 25cm x 10cm with an optional flap.

3D.75

Standard bag with additional gusset to provide extra capacity produced by PBS International. 75cm x 15.8 cm x 15.8cm. Comes with 1 window at 25cm x 10cm with an optional flap.