Def. Of Terms, Gen

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- Nonliving factors such as light, temperature, wind, fire, soil, water, air.

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Abiotic factors

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* Habituation of a species to a different climate or environment. The process of increasing a plant's hardiness to outdoor conditions.

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Acclimatisation

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The process of evolutionary (genetic) fitting individuals or groups to their environment. Also the changed structure or function itself

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Adaptation

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The ability of a population to respond to changed environmental conditions.

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Adaptability

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- Genes conveying effects additively. Gene actions combine to produce a value in a trait in a simple linear way. Additivity is the basis for much quantitative genetics theory and breeding efforts.

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Additive genes

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The genetic variation that depends on that different individuals have different breeding value (or general combining ability). The part of genetic variation that responds to mass selection, or pick-the-winner selection.

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Additive variance

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*Meristems developing into buds, shoots or roots in places not directly associated with apical meristems.

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Adventitious

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One of several alternative forms of a gene occupying the same locus on a particular chromosome. Alternative states of a gene.

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Allele

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*Separated. Allopatric populations do not freely exchange genes.

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Allopatric

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A statistical analysis by which F values (variance ratios) are composed in such a manner as to determine the probability that differences among populations or treatments are too large to be due to chance.

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Analysis of variance (ANOVA)

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A condition in which the chromosome number is not an exact multiple of the basic number.

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Aneuploidi

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- The most extreme point of growth if a plant

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Apex

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- the terminal bud influence.

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Apical dominance

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- A collection of trees

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Arboretum

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Mating is depending on the performance for some value of the parents (PAM means individuals with similar value mate)

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Assortative mating * (Positive Assortative Mating = PAM)

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- Crossing a hybrid back to one of the original parental types.

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Backcross

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Selection of parent trees based on results from a progeny test. (See Forward selection.)

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Backward selection

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The initial set of genotypes from which selections will be taken to establish a breeding program (e.g. the wild forest). It is sometimes referred to in the same meaning as recruitment population (in the first generation they are actually the same, and it can be referred to as one of the populations in a stratified tiered structure).

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Base population (source population, founder population)

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A statistical method which utilities matrix algebra to predict breeding values for any trait or selection index; in BLP fixed effects are assumed to be known. BLP is especially suited for analyses of messy or unbalanced data. (See unbalanced)

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Best linear prediction* (BLP)

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A statistical method, which predicts breeding values for any trait or selection index; unlike BLP, in BLUP the fixed effects are estimated. Like BLP; BLUP is well suited for analyses of messy or unbalanced data. (See unbalanced)

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Best linear unbiased prediction (BLUP)

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The variability (both in numbers and frequency) of the organisms and the genetic variability within each species. The term can be used to describe a particular site, a general habitat type, a small or large geographic region, or sometimes (less correctly), the genetic diversity of a particular species or population. The term can also be used to describe the total variability within and among species of all living organisms and their habitats.

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Biodiversity*(Biological diversity)

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Factors related to life (e.g. presence, behaviour or interaction of living beings)

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Biotic factors -

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The successive alternation of recruitment, candidate and breeding populations in one breeding generation.

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Breeding cycle

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An orchard where (usually) control-pollinations are made. Many more parents are usually maintained in a breeding-orchard than in a seed-orchard. Management usually focused on early and prolific flowering and good seed quality.

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Breeding orchard

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(breeding arboretum, if clones it may be known as clone bank)

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Breeding orchard

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Strictly it is the genotypes which transmit their genes to following generations. Could be individuals, which are mated to create the next generation in the recruitment population. Or in a wider sense it could be the trees breeders work with (breeder's populations or breeding stock perhaps could be used when this is referred to).

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Breeding population

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The genetic influence of an individual which is expected to be inherited to its progeny. The value of an individual as parent. The breeding value is double the general combining ability. May refer to individual traits or a selection index composed of many traits. Cf. general combining ability.

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Breeding value (BV, g)

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The ratio of total genetic variance to phenotypic variance. Used to estimate the degree of genetic control of a trait in a population. Useful for predicting response to clonal selection. (see heritability)-

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Broad-sense heritability

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- Unorganized tissue, often initiating at the cut end of a cutting or explant.

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Callus

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- Non-genetic causes of variation (C here stands for "common" so it may be a maternal effect)

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C-effects

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A tree that has been tentatively selected or created for possible inclusion in a breeding program. (See plus tree and elite tree.)

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Candidate tree

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- trees which are planted to serve as a base for forward selection or in some they selected from that for further studies (e.g. phenotypic selections).

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Candidate population

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- The geographic region in which the greatest variability of a crop occurs.

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Centre of diversity*

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* - In accordance with standards and guaranteed by a certificate from an official agency.

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Certified

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A distinctive but not necessarily invariable feature exhibited by all individuals of a group and capable of being described or measured; e.g. colour, size, performance. A character of a given individual will have a certain phenotype as determined by the individual's genotype and environment.

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Character (trait)

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* - Consisting of diverse genetic constitution.

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Chimera

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A microscopic, usually rod-like, body carrying the genes. Number, size and form of chromosomes are usually constant for each species.

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Chromosome

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The number of chromosomes found in a typical individual of a particular species. Typically the sex cells (the gametes) of a species have one-half the number of chromosomes found in the vegetative portion and are said to be haploid. (See polyploid.)

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Chromosome number

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* Abnormal chromosomal part resulting from the loss, duplication or rearrangement of genetic material

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Chromosomal aberration

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The number of chromosomes characteristic of a species, eg. 24 for a diploid (2n) Pinus

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Chromosome number

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* - A geographical gradient of phenotype or genotype within the species' range.

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Cline

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A field planting of several to many vegetatively propagated plants. Such tests furnish estimates of the relative performance of different genotypes, but do not necessarily provide information on breeding behaviour.

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Clonal test

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To propagate a plant asexually usually by grafting, rooting cuttings, tissue culture, or apomictic seed. Except mutations, all plants from a clone are genetically identical. (This is the usage most common in agronomy, horticulture and forestry.) (See ortet and ramet.);

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Clone

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To regenerate a whole plant from a single cell. (This usage is common in tissue culture research.);

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Clone

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To identify and isolate a gene controlling a specific trait from an organism or a gene or piece of DNA replicated (usually) in a host bacterium.. (This usage is common in molecular biology

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Clone

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A group of plants produced from cuttings, stump or root sprouts, tissue culture, or some other method that produces offspring genetically identical to the original plant. Most commonly used in forestry to establish grafted seed orchards, but is also used for commercial plantations. All uses imply genetically (nearly) identical material, and reproduction by mitotic division.

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Clone

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A quantification of relatedness, the probability that genes taken from different individuals are identical by descent. (Synonyms are coefficient of coancestry, kinship, consanguinity). The coancestry of mates becomes the inbreeding of the progeny. Coancestry of full sibs (from unrelated non inbred parents) is 0.25, of half-sibs 0.125 and of first cousins 0.0625. It is possible to talk about self-coancestry, thus an individuals relatedness with itself. That is (for non inbred individuals) 0.5.

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Coancestry

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A numerical value expressing the influence of one of the parents on its progeny. Good general combining ability (GCA) is the ability of an individual to produce progeny with high genetic quality, when crossed to many other individuals in the population

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Combining ability, general

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A numerical value expressing the deviation of a full-sib families performance compared to what would be expected from the GCA of the parents. Good specific combining ability (SCA) is when the progeny from a particular full-sib cross perform better than what would be predicted from the general combining ability of the sum of the parents.

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Combining ability, specific

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* - An immature cone (strobilus) in the conifers

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Conelet

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To purposely pollinate the female flowers of a tree with pollen from a known source, usually one specific tree. Usually the flowers are protected from undesirable pollen by covering them with a pollen-tight cloth or paper bag before they are receptive and adding known-source pollen at receptivity. Full-sib families are produced.

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Controlled pollination

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New shoots from the stump or roots. To coppice is to cut the main stem at the base or to injure the roots in order to utilise coppicing for regeneration.

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Coppice

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To collect pollen from one tree to pollinate a tree.

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Cross

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The progeny of a control pollination.

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Cross

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Exchange of segments between homologous chromosomes at meiosis.

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Crossing over

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Storing of living material (e.g. cells, tissue, seeds) at very low temperatures, usually in liquid nitrogen (-196).

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Cryopreservation

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A 'cultivated variety', given a non-Latin name and designated by 'cv'. Any clone, race, strain or product of breeding deemed worthy of a separate name.

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Cultivar

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A shoot, twig or other plant part removed from the donor plant, usually for the purpose of inducing roots.

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Cutting

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The study of the cell, i.e. its structure, function, development and reproduction.

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Cytology

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- See fitness, sometimes used as a contrast to Domestic fitness to emphasise that it is a natural process.

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Darwinian fitness

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The physical movement of clones or other genetic units from one site (usually a nursery) to another (usually plantations), often including their spatial configuration on the recipient site.

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Deployment

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A mating design and subsequent progeny test resulting from the crossing of 'n' parents in all possible n2 combinations including selfs and reciprocals. (Because of severe inbreeding depression in the selfs, these are sometimes skipped but the test still called a "full" diallel.)

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Diallel, complete (or full)

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A partial sampling - any individual family or type of family may be omitted. In either the complete or incomplete diallel, identities of both seed and pollen parents are maintained for each family.( See Pedigree)

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Diallel, incomplete or partial

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Organisms are unisexual (male or female).

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Dioecious

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- an individual with two homologous set of chromosomes.

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Diploid (2n)

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- see fitness

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Domestic fitness

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In classical Mendelian genetics, the masking of the action of one allele by another. Interaction between alleles at homologous loci. If an individual with red flowers is crossed with an individual with white flowers and all progeny have red flowers, then the allele for red pigment is fully dominant over the allele for white flowers. It is possible to talk about complete dominance; incomplete dominance(or partial dominance) where the phenotype is more similar to a homozygous of the dominant type than the homozygous of the recessive type; over dominance, where the heterozygote has a phenotype outside the range of the homozygotes; and co-dominance (where both alleles are expressed almost equally).

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Dominance

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An action or process that is detrimental to the genetic qualities of a population. Usually applied to human actions, such as high grading, which would degrade the value of the local gene pool.

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Dysgenic

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Random fluctuations in gene frequency when a small number of individuals form a (breeding) population.

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Drift, genetic drift

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A sub-population of a species that occurs in a particular well-defined environment, usually showing better adaptation to that environment than the species as a whole. (See cline.)

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Ecotype

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From some aspect a population could be characterised by the corresponding size of an ideal population with the same characteristic. The increase in inbreeding or the dispersion occurring over time in a dynamic population can be described by the size of constant random mating population, which experiences the same expected changes in inbreeding or variance of gene frequencies (effective population size in the inbreeding or variance sense). A population at a certain moment can be described by the size of an ideal population, where the average relatedness is the same (status number).

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Effective population size (effective number)

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A technique that allows separation of proteins and other large molecules based on their size, configuration and charge.

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Electrophoresis

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A tree that has been shown by progeny testing to produce superior offspring (See plus tree and candidate tree.)

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Elite tree

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Genetically advanced intensively managed population in a short term breeding program. Sometimes used in same meaning as nucleus population.

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Elite population*

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* - A plant or animal species or subspecies native to a small region.

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Endemic

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Typically triploid tissue in the seeds of many angiosperms. Its hereditary characters may not be the same as those of the embryo. The so-called endosperm of conifers is haploid tissue which genetically can be seen as the female gamete.

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Endosperm

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* Removal of immature sexual structures to avoid selfing or unwanted crossing (in trees crosses are usually avoided by bagging instead).

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Emasculation

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- Interaction between genes at different loci.

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Epistasis

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- A non-native species (or sometimes population) introduced into a new area

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Exotic

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Conservation of a plant outside of its original or natural habitat. Maintaining the genetic variability of a population in a different environment or geographic location than where it evolved, i.e., plantations of exotic species, breeding orchards, cold storage of seed or pollen.

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Ex situ gene conservation

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The first (filial) generation after a cross. According to simple Mendelian genetics the progeny from an F1 cross will be phenotypically fairly uniform.

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F1

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The second (filial) generation after a cross, produced by intercrossing (or selfing) individuals from the F1 generation. The progeny of an F2 cross is according to simple Mendelian genetics expected to be more variable phenotypically than the F1.

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F2

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*A mating scheme in which m males are each crossed to the same n females is a mxn factorial. For example, if 2 trees designated male are crossed to each of 3 designated female, that is a 2x3 factorial with 6 total crosses.

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Factorial mating

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- A group of closely related genotypes (with at least one parent in common). (See sib, polycross, half-sib, full-sib, open pollination, wind pollination, selfing). One parent in common = half sibs; both parents in common = full sibs, selfing family = family obtained by self-pollinating a genotype

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Family

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Tested open-pollinated, polycross or full-sib families are deployed as single families to commercial plantations.

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Family forestry

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- The selection of families based on their mean performance.

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Family selection

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A test done at close spacing under near-ideal conditions, usually for the purpose of early culling.

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Farm-field test

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Union of the nucleus and other cellular constituents of a male gamete (sperm) with those of a female gamete (egg) to form a zygote. In some species, fertilisation may occur months after pollination.

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Fertilisation

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- An individuals ability to give progeny (cf. reproductive success).

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Fertility

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In classical genetics, the ability of an individual or population or allele to both survive and reproduce in a particular environment. A measure of relative reproductive success. An expression for an individuals contribution to the next generation in relation to other individuals. The only trait selected by natural selection.

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Fitness

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The ability of a population to survive, reproduce and adapt genetically to a changing environment. (See gene pool and heterozygosity.)

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Fitness, adaptive

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The ability of a population (usually a whole species or ecotype) to survive, reproduce, and adapt genetically to a changing environment. (See gene pool and heterozygosity.)

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Fitness, evolutionary

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- The adaptedness in Nature

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Fitness, Darwinian

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The ability of a genetic entry to produce utilities of Man.

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Fitness, Domestic -

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Angiosperm reproductive structure bearing pistils, stamens, or both, and usually also sepals and petals. So-called flowers of conifers are the male and female strobili before and during pollination.

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Flower

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The study of heredity in forest trees. Note that many studies concerning gene control in forest trees do not fit under this definition. To make talk about heredity meaningful there must be some polymorphism

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Forest genetics

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The application of genetic principles to the genetic improvement and management of forest trees. In a narrow sense the term refers to propagation by controlled pollination, but usually it refers to a broader concept.

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Forest tree breeding

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*The application of genetic principles to the genetic improvement and management of forest trees may refer to tree breeding in combination with cultural practices. Can often be seen as synonymous to forest tree breeding

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Forest tree improvement

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Choosing the best individuals out of a progeny test for use in seed orchards and/or subsequent generations of breeding. (See Backward selection.)

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Forward selection

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* The process by which and area of a continuous habitat is broken into smaller pieces or fragments.

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Fragmentation

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* - The first generation of a breeding population (in forest tree breeding often the initial plus trees)

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Founders

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- see family

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Full sib

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. The influence a parent has on its progeny in general. See additive genetic variation and combining ability.

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GCA General combining ability.

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(See genetic gain.)

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Gain

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- haploid germ cell

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Gamete

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The basic unit of inheritance. A gene corresponds to a DNA segment. Many genes comprises 1) coding sequences corresponding to a protein (=exon); 2) non coding sequences (intron); 3) a regularatory part (promoter); and 4) an end sequence.

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Gene

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*The selective synthesis of DNA that results in multiple copies of a gene, for example the synthesis of many copies of ribosomal-RNA genes as a means of enhancing protein synthesis.

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Gene amplification*

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A collection of germplasm (seeds, pollen, whole plants, extracted DNA) collected and maintained so as to sample as much as possible of the genetic variability in a population.

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Gene bank

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- see germplasm conservation

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Gene conservation

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- Population used to maintain original genetic variation in species.

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Gene conservation population

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It can be quantified as the probability that genes are different

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Gene diversity

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The movement of genes among different populations of a species or among related species. The exchange of genetic material between populations due to dispersal of gametes and zygotes. Cf gene migration.

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Gene flow

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The gene pool does not consider how genes are organised in zygotes.

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Gene pool

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– A “map” of an organism’s genome, identifying and locating its DNA sequences (genes).

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Gene map

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– (often t), in reality it is seldom distinct generations, but in connection with breeding strategies generations are often regarded as distinct.

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Generation

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The distribution of genetic variation in a species, usually described hierarchically as variation at the regional, local, family and individual levels, and also relating to proportions of additive and non-additive inheritance.

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Genetic architecture*

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* A measure of the genetic association between two characters. Often it can be seen as the correlation between breeding values (but not correlation between phenotypes).

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Genetic correlation

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The genetic variation present in a population or species. May be given more specific meanings or be assigned quantitative values in somewhat different ways, the most obvious one is "expected heterozygosity".

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Genetic diversity

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Changes in gene frequency in small populations due to random chance. Alleles may be lost because of genetic drift. Genetic drift can cause increased inbreeding, increased coancestry, increased genetic distance between populations and faster changes from the original population.

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Genetic drift

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Inserting, suppressing, or removing genetic material in another way than conventional matings.

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Genetic engineering

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- Loss of genetic diversity over time or reduction of the genetic base

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Genetic erosion

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In a narrow sense the genetic change achieved by artificial selection in a specific trait. Gain is dependent on selection intensity, genetic variation and heritability. Gain can be seen as the average genetic value of an improved population compared to that of the initial population.

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Genetic gain

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(in seed orchards) refers to the removal of orchard genotypes based on their supposed breeding value (rouging is equivalent).

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Genetic thinning

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– Organism that result from the introduction, removal or suppression of genes using DNA manipulation technology

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Genetically modified organism (GMO)

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is the basic science dealing with causes of resemblance and differences among organisms related by descent.

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Genetics

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Maintenance of the genetic variability of a population. (The term is used in preference to "germplasm preservation” to reflect the ever-changing nature of living populations.)

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Gene conservation = Germplasm conservation*

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- migration to a recipient population from another population.

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Gene flow

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– All the genes of a living organism.

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Genome

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- The activity of determining the DNA sequences of genes, what they do, and how they affect cell and organism function.

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Genomics

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- The specific set of genes possessed by an individual, both expressed and recessive

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Genotype

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Changes in rank or level of performance among genetic entries when tested in different environments. The performance of a genetic entry in a certain environment cannot be statistically fully explained by a value for the entry added to another value for the environment, but an interaction term has to be considered.

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Genotype-environment interaction

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The phenotypic differences among native trees growing in different portions of a species' range. If the differences are largely genetic rather than environmental, the variation is usually specified as racial, ecotypic, or clinal.

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Geographic variation

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Genetic material.

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Germplasm

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A form of cloning in which a bud or twig (called a scion) of the clone is inserted into a slit on a rooted and established stock plant.

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Graft (grafting)

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* The genetic merit of a group is expressed as a function (weighted average or index) of its breeding value and gene diversity.

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Group merit*

Front 136

Maximising the group merit of selections given the candidates and group merit measure

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Group merit selection

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- see family

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Half-sibs

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- one set of genes (chromosomes, "n", e.g. in germ cells or in the "endosperm" of conifers

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Haploid

Front 139

Expected genotype frequencies as a function of gene frequencies in a population following random mating.

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Hardy-Weinberg equilibrium

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*The repeated clipping of an ortet and/or some of its ramets to produce a low hedged plant. The purposes of this procedure are to slow or halt maturation of the plant, and to control its size and shape for efficient operation.

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Hedging

Front 141

General concept: The degree to which progeny resemble their parents. Strictly, the ratio of genetic variance to phenotypic variance. Narrow-sense heritability refers to the additive part of genetic variance while broad-sense heritability takes all genetic variance into consideration. Note that heritability refers to a squared quantity.

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Heritability

Front 142

The proportion of the total phenotypic variability for which genetic differences are responsible.

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Heritability, broad sense (H2)

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The proportion of the total phenotypic variability that is due to additive genetic variability.

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Heritability, narrow sense (h2)

Front 144

Having different alleles at a locus. When used to refer to the whole genotype, the term indicates that the individual has different alleles at many relevant loci. When used to refer to a species as having low or high heterozygosity relative to other species, the term indicates that the species has a relatively high number of variable loci.

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Heterozygous

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* - Hybrid vigour

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Heterosis

Front 146

The pair of chromosomes in a diploid individual that have the same overall genetic content. One member of each homologous pair of chromosomes is inherited from each parent. They form physical pairs at meiosis.

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Homologous chromosomes

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Having two identical alleles at a locus, at most relevant loci, or in the entire species. (See heterozygous.)

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Homozygous

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Progeny from a cross among dissimilar genotypes. In forestry, the term is usually used for crosses between species.

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Hybrid

Front 149

Interspecific: a cross between species. Intraspecific: a cross between populations within a species or between individuals (often of contrasting genotype) within a population. Introgressive: the moving of genes from one species or population to another by repeated backcrosses.

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Hybridisation

Front 150

Conservation of plants in area where they developed their distinctive properties. The management of planted stands of trees to protect them and insure survival, growth and identity; the conservation or preservation of trees as seed, pollen, tissue culture, or excised plant parts. Maintaining the genetic variability of a population in approximately the same geographic and ecological conditions under which it evolved.

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In situ gene conservation

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"In glass"; in aseptic culture under laboratory conditions. See in vivo.

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In vitro

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Grown in natural conditions (in the field, greenhouse, etc). See in vitro.

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In vivo

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The ideal type or perfect specimen. A description or illustration of what the final goal of genetic improvement for a species would look like; An idealised multitrait characterisation; for example, a crown that is long, narrow and dense with high branch angles. The ideotype is developed without regard to heritabilities for the individual traits involved or economic considerations. It is not intended to be a practical field guide for selecting, but as a starting point for breeding.

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Ideotype

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Genes at the same locus are copies of the same original gene in some (rather recent) ancestor.

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Identical by descent* (IBD)

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Progeny between matings of related individuals are affected by inbreeding. In open pollinated tree species, inbreeding usually leads to reduced seed set and germination, and reduction of growth, health and survival. (See inbreeding depression and inbreeding coefficient).

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Inbreeding

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(see inbreeding) Inbreeding can be quantified by coefficient of inbreeding (F), the probability that the different genes occupying the same locus in homologous chromosomes in the same diploid are identical by descent (IBD). The inbreeding of the progeny is the coancestry of the parents (cf. coancestry, identical by descent). F can be 0 (the base population) or 1.0 (fully homozygous). A negative F indicates outcrossing and greater heterozygosity than in the base population. Note that concepts like inbreeding and coancestry needs a defined base-line (reference point) and thus can be seen as relative rather than absolute measures.

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Inbreeding coefficient

Front 157

The reduction in vigour often observed in progeny from matings between close relatives. Inbreeding depression is due to the expression of recessive deleterious alleles and is usually severe in open-pollinated outcrossing species (most forest trees) that occur in fairly high population densities

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Inbreeding depression

Front 158

1) A failure of some process leading to fertilisation. 2) Inability to form or maintain a successful union between scion and rootstock after grafting.

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Incompatibility

Front 159

The movement of genes from one population into another through hybridisation followed by backcrossing. Usually refers to movement of genes from one species to another or among sub-species that have been geographically isolated then brought back together by changes in the species ranges or planting of exotic populations. (See gene flow.)

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Introgression

Front 160

- Distinct and separable but very similar enzymes, which are coded by the same locus. (Also called isoenzymes or allozymes).

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Isozyme

Front 161

A population of trees of a non-native species that has undergone one or more generations of natural selection in a new environment, i.e., Norway spruce in New York State.

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Land race

Front 162

A dimensionless parameter expressing the area of leaf surface over unit area of ground.

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Leaf-area index

Front 163

It is usual in many organisms that normal individuals are carrier of genes, which have little effect in heterozygotes, but are recessive and detrimental or harmful in homozygous form. Thus e.g. conifers are often carriers of a genetic load, which is released by inbreeding (in particular selfing), and actually reduces the amount of selfing (inbreeding) in vital seeds compared to the frequency of selfing pollen.

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Lethal load, lethal genes*

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The association of inherited characters because the genes are in the proximity on the same chromosome. Linked genes tend to follow to the same gamete and thus be transmitted to the progeny together.

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Linkage

Front 165

The position of a gene on a chromosome.

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Locus (pl. loci)

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Native to the locality in which seedlings are to be grown, belonging to the indigenous geographic race. In practice it can be a seed source with origin within a certain distance or elevation from the planting site.

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Local seed source

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Genetically less advanced part of breeding cycle which is managed less intensively; see nucleus breeding.

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Main population*

Front 168

An approach to identify linkage between genetic markers and important genes, e. g. quantitative trait loci (QTL). When selection can be made on the markers.

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Marker assisted selection (MAS)

Front 169

The effect of the mother which can not be ascribed to the inheritance of nuclear genes (e.g. seed appearance and weight are often maternally conditioned)

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Maternal effect

Front 170

The pattern of pollinations set up between individuals for an artificial crossing program

Back 170

Mating design

Front 171

In a conifer, the haploid cells and tissues developing from the maternal gamete, with nutritive and other functions for the contained zygote.

Back 171

Megagametophyte

Front 172

A special cell division that results in a reduction of somatic-cell chromosome number (2n) to gamete chromosome number (n).

Back 172

Meiosis

Front 173

An undifferentiated plant tissue, often with rapidly dividing cells, from which new tissues or organs arise.

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Meristem

Front 174

* - The male cells produced by sexual cell division and maturing to pollen grains.

Back 174

Microspores

Front 175

- May be interpreted as a general term for vegetative in vitro propagation.

Back 175

Micropropagation

Front 176

- Normal division of a nucleus into two identical daughter nuclei.

Back 176

Mitosis

Front 177

A deployment option for clones (or, similarly for families in monofamily blocks) in which each clone (family) is established in a pure block. Diversity may be maintained by a mosaic of blocks of different genetic entries.

Back 177

Monoclonal blocks

Front 178

* - Individual organisms can produce both male and female gametes; i.e. Scots pine.

Back 178

Monoecious

Front 179

- No polymorphism (see polymorphic)

Back 179

Monomorphic

Front 180

Sublines of the general breeding population purposefully selected for different sets of traits or deployment destinations.

Back 180

Multilines

Front 181

Trees used to multiply the genetically advanced material for commercial purposes (e.g. seed orchards). Other terms used for similar purpose: propagation population, (seed) production population!

Back 181

Multiplication population*

Front 182

See multiple population.

Back 182

Multiple-population breeding -

Front 183

When there are more than two alleles, which can occupy a locus (several variants of a gene).

Back 183

Multiple alleles

Front 184

The breeding population is subdivided in several smaller subpopulations that are bred for different objectives (e.g. different areas).

Back 184

Multiple population breeding system*

Front 185

*Subpopulations of the general breeding population purposefully selected for different sets of traits or deployment destinations.

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Multiplication population*

Front 186

A sudden change in the genotype. It can be caused by a small change in the DNA sequences. The term can also used for changes in chromosome number or breakage or rearranging of individual chromosomes

Back 186

Mutation

Front 187

Alleles subject to no (or very weak) selection pressure, and thus useful as evolutionary clocks, for mating-system estimation, and similar selection-free purposes.

Back 187

Neutral alleles

Front 188

- The cell part made up chiefly of the chromosomes or Genetically best part of breeding cycle which is managed intensively; see nucleus breeding.

Back 188

Nucleus

Front 189

*Breeding scheme where populations in breeding cycle are divided into intensively managed nucleus with top-ranking genotypes and less intensively managed genetically less advanced main population.

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Nucleus breeding*

Front 190

Pollination occurring due to wind or insects (cf. wind pollinated and sib); a mating that is not controlled. An open pollinated family is typically a mixture of selfs, full-sibs from adjacent trees, crosses from more or less distant relatives and pollen parents situated far away

Back 190

Open pollination

Front 191

Original geographic area where the genetic material originally existed as wild (see provenance, seed source)

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Origin

Front 192

The original plant from which a clone is started. The original plus tree used to start a grafted clone for inclusion in a seed orchard is the ortet. (See ramet and clone.)

Back 192

Ortet

Front 193

Matings (controlled or natural) among unrelated individuals. May also refer to a species that has specific barriers to selfing, or exhibits such inbreeding depression that inbred individuals never reach maturity. (See selfing.)

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Outcrossing

Front 194

A special case of dominance in which the heterozygote is, on average, outside the range of the averages of the two homozygotes (see dominance).

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Overdominance

Front 195

Ranking of parents based on estimates of their breeding value from tests of their progeny.

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Parental ranking

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* - random mating

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Panmixis (panmixia)*

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- Record of ancestry (parentage).

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Pedigree

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All parents, grandparents . . . of a particular genotype are known all the way back to some identified founders

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Pedigree, full*

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* Some, but not all, ancestors of a particular genotype are known, usually the female parents. Partial pedigrees are most common where open-pollinated or polycross seed is used for progeny tests.

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Pedigree, partial

Front 200

A breeding system where all the ancestors of any individual in the population are known back to the original plus trees selected in wild stands. The system depends on control pollination for all matings.

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Pedigree breeding*

Front 201

- Relations between plant development and seasonal climatic changes.

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Phenology

Front 202

The observed characteristics of an individual. The phenotype is determined by the genotype interacting with the environment in which it is grown. Phenotype = Genotype + Environment

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Phenotype

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The degree to which different phenotypes are produced by the same genotype (clone) in different environments.

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Phenotypic plasticity

Front 204

Day length. Used to describe the relationship between phenology and episodes of light. (Actually usually the night length is physiologically more significant

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Photoperiod

Front 205

A branchlike growth form of an independent plant, usually at an angle other than vertical and often bilaterally metrical. This is common for mature tree clones.

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Plagiotropic

Front 206

In a field study, a group of trees, all from the same entry (family, clone, provenance . . .) planted together (usually). (See block and randomised-block design.)

Back 206

Plot

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In a field study, a group of trees, all from the same genetic entry planted together. A five-tree row-plot is a common design for forest genetics experiments.

Back 207

Plot, contiguous

Front 208

In a field study, a group of trees, all from the same entry planted in the same block, but not planted together. The non-contiguous interlocked-plot design allows tests to be thinned systematically and still maintaining uniform spacing.

Back 208

Plot, non-contiguous

Front 209

Genetic tests are most powerful when each plant constitutes a single unit

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Plot, single-tree-plot (STP)

Front 210

A phenotypically superior tree. (See elite tree and candidate tree.)

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Plus tree

Front 211

(alien pollen, pollen migration, wild pollen, gene flow) refers often in connection with seed orchards to the phenomenon that some of the pollen fertilising orchard genotypes origins outside the seed orchard.

Back 211

Pollen contamination

Front 212

- Deposition of pollen on the receptive part of the female flower.

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Pollination

Front 213

- using a pollen cocktail as pollinator

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Polycross

Front 214

A progeny test to assess general combining ability from crosses among selected parents. Identities can be maintained only for the seed parents. A mixture of pollen is artificially applied to each female parent. (Note that agriculturists often use "topcross" to describe this situation).

Back 214

Polycross test

Front 215

* - Several embryos are formed in one ovule, common in some conifers

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Polyembrony

Front 216

The existence of different gene forms (alleles) in a population in substantial frequency.

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Polymorphism

Front 217

A cell, tissue, individual, population, or whole species having more than twice the basic number "x*n” of chromosomes of the ancestral species. Polyploidy may lead to increased growth rates (Populus) or severe dwarfing (Pinus). Three sets of chromosomes are called triploid, four sets-tetraploid, six sets-hexaploid, etc. (See chromosome number, cf. also haploid and diploid.)

Back 217

Polyploid

Front 218

A group of individual trees having some characteristics in common, either location, family ancestry, or intended use. Usually it is meant a group of individuals form a limited area with some adaptation to where they grow and in genetic contact with each other. Note that the term "population" either can refer to a defined group of individuals or to a group of individuals, which change by time (e.g. "the human population has increased the last centuries"). This distinction can cause sever misunderstanding, e.g. concerning what is meant by "effective population size".

Back 218

Population

Front 219

The focus is on the frequencies of the frequency of individual genes and genotypes and how they change.

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Population Genetics

Front 220

Trees used to produce the commodities forestry is aimed to, i.e. practical plantations (compare multiplication population).

Back 220

Production population - (PP)

Front 221

Often a test established to compare the offspring of different parents for the purpose of evaluating the breeding value of the parents. (See backward selection.). However, progeny tests can often by used for other purposes also.

Back 221

Progeny test

Front 222

Any type of plant to be used for reproduction. It might be a seedling, a rooted or unrooted cutting, a graft, or a tissue-cultured plantlet.

Back 222

Propagule

Front 223

- The more or less specified area a material is collected from or originate from. Prefer origin if referring to where the population evolved prior to human intervention.

Back 223

Provenance

Front 224

A test comparing trees grown from genetic materials collected in many parts of a species range.

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Provenance test

Front 225

Prediction or estimation of quantitative genetically related traits (e.g. heritability, breeding value and inbreeding).

Back 225

Quantitative genetics

Front 226

A trait typically measured on a continuous scale, such as height or weight, which results from the combined action of multiple genes in conjunction with environmental factors. Thus one could see quantitative traits as continuous traits different from the distinct discontinuous trait

Back 226

Quantitative trait

Front 227

A sub-population, usually fairly large, of a species exhibiting some degree of phenotypic (and presumably genotypic) uniformity among individuals within the population and distinct from the species as a whole. It is usually an interbreeding unit.

Back 227

Race

Front 228

A vegetatively reproduced copy of a plant. Each ramet will have (almost) precisely the same genotype as the original parent tree, known as the ortet. (See clone and ortet.)

Back 228

Ramet

Front 229

A large high-angled branch, often resulting from one member of a fork being partly suppressed by the more dominant member.

Back 229

Ramicorn

Front 230

- In the ideal case, each individual in the population has the same probability of mating with every other individual. In practice, no selection influences the matings that occur.

Back 230

Random mating

Front 231

The most common experimental design used in progeny, provenance and clonal field tests. Each entry in the test is replicated once in each block. All the entries are arranged randomly within a block and a new randomisation pattern is used for each block. (See replication, block, and plot.)

Back 231

Randomised complete-block design

Front 232

- is used to describe the trait value change of a genotype studied along an environmental gradient.

Back 232

Reaction norm

Front 233

- Condition of the female flower that permits effective pollination

Back 233

Receptivity

Front 234

- see dominance

Back 234

Recessive

Front 235

- New combinations of genes are formed

Back 235

Recombination

Front 236

The repetition of a cross where the sexual function of the parents is reversed, i.e., female B x male A is the reciprocal of female A x male B.

Back 236

Reciprocal cross

Front 237

*A complicated breeding scheme in which selection within each of two independent lines is based on progeny tests based on crosses between the lines. It is meant to select for both additive and non-additive genetic variation.

Back 237

Reciprocal recurrent selection*

Front 238

* Individuals having new combinations of the genes (alleles) of the parent(s), the term often used when the genes are linked.

Back 238

Recombinants

Front 239

* The population in the breeding cycle from which selections for candidate population are made (or the whole recruitment population could be considered as candidates); progeny of previous generation breeding pop,

Back 239

Recruitment population*

Front 240

Selection of individuals or families and inter-mating them or allowing them to inter-pollinate to produce the next generation. Usually the process is repeated several times (for long-lived perennials such as trees) or many times (for annuals.) The technique is used to improve the overall performance of the population rather than to select outstanding varieties for immediate use.

Back 240

Recurrent selection

Front 241

In a genetics test a replication contains one plot of each entry in the test. (See randomised block design , block, and plot.)

Back 241

Replication

Front 242

- Number of successful gametes, thus number of offspring, of a parent.

Back 242

Reproductive success

Front 243

* The ability of a population to persist in a given environment despite disturbance or reduced population size. The resilience of a population is based upon the ability of individuals within the population to survive (fitness) and reproduce (fecundity) in a changed environment and the genetic variability of the population which allows the production of new genotypes.

Back 243

Resilience

Front 244

Relative ability to endure pest or other damaging influences. Could comprise vertical or horisontal, escape. Could vary between immunity to susceptibility.

Back 244

Resistance

Front 245

Variation in the lengths of DNA fragments resulting from predictable cutting by restriction enzymes, which cleave the DNA double helix at specific nucleotide sequences

Back 245

Restriction fragment length polymorphism (RFLP)*

Front 246

* The small organelle that is the site of protein synthesis.

Back 246

Ribosome

Front 247

To remove trees that have an undesirable phenotype, or that have been shown through progeny tests to have a less desirable genotype from a seed orchard, seed production area, or nursery bed.

Back 247

Rogue

Front 248

- A rooted plant, usually a seedling, on which a scion is grafted.

Back 248

Rootstock

Front 249

. Can refer to the degree to which the average performance of a specific (usually full-sib) family departs from the average of its parental breeding values; sometimes used in a similar sense to note the departure of an individual clone from the performance of its sibs; sometimes used to note the degree of non-additive genetic variation in a population.

Back 249

SCASpecific combining ability

Front 250

A twig, branchlet, bud, or other vegetative cutting (aerial part) to be grafted onto the root-system of another plant.

Back 250

Scion

Front 251

* Selecting for a particular trait, often used when referring to the application of a specific treatment such as white pine blister rust spores or a herbicide, and then looking for resistant individuals. Usually implies checking large number of individuals at one time

Back 251

Screening

Front 252

- Seeds, usually of known origin, having uniformity of species, source, quality and year of collection.

Back 252

Seedlot

Front 253

A stand or plantation designated for collection of seeds for reforestation purposes. It may be rogued of inferior trees and treated in such a manner as to produce large quantities of seed. The wood harvest is usually also an important consideration and the establishment and management is similar to commercial stands, usually seed production was not an initial consideration at establishment.

Back 253

Seed production area (stand)

Front 254

A plantation established for the production of tree seed. Typically it is clones or seedlings from selected trees, isolated to reduce pollination from outside sources and managed for early and abundant seed production.

Back 254

Seed orchard

Front 255

- The location where a seedlot was collected.

Back 255

Seed source

Front 256

A set of rules for collecting seed and planting seedlings so that genotypes are not moved to microclimates or soils within which they will be mis-adapted. Usually seed transfer guides describe the maximum movement from the point of collection in miles east and west, north and south as well as feet in elevation. (See seed zones.)

Back 256

Seed transfer guide

Front 257

A designation of a group of seeds with some factor in common, i.e., year of collection, stand or seed orchard, individual "+" trees, point of origin in a provenance test, a half- or full-sib family.

Back 257

Seedlot

Front 258

Choosing individual trees or populations, usually the selected ones have desirable characters to obtain genetic improvement. Usually meant artificial selection as contrasted to natural selection. There are different types of selection: Phenotypic selection (individual selection, mass-selection); family selection; index selection; indirect selection; early selection; combined (index) selection; trait-index selection; tandem selection; recurrent selection, reciprocal recurrent selection; truncation selection; within-family selection; balanced selection; unbalanced selection.

Back 258

Selection

Front 259

The difference between selected trees, families, or clones and the average of the population from which it was taken.

Back 259

Selection differential (S)

Front 260

A standardised selection differential between the average of the selected population and the average of the population selected from (with average 0 variance 1). Often predictions of selection intensity are based on the normal distribution. Sometimes it is used referring to the percentage selected, prefer when to use selected proportion.

Back 260

Selection intensity (i)

Front 261

- Choosing (the best) clones from a clonal test.

Back 261

Selection, clonal

Front 262

* - based on weighted information from the individual and its relatives

Back 262

Selection, combined

Front 263

Choosing genotypes on the basis of a weighted score, which can combine economic value and heritability of several desirable traits and which can include information from relatives

Back 263

Selection, index

Front 264

Choosing trees on the basis of their phenotypes (appearance) only.

Back 264

Selection, mass (phenotypic selection)

Front 265

Choosing individuals out of families, mate them, then select individuals out from these matings repeated several to many times. Most tree improvement programs are based on recurrent selection.

Back 265

Selection, recurrent*

Front 266

Selecting for two or more traits sequentially rather than simultaneously. The technique is useful when one trait can be evaluated early and a second trait only after a number of years, or when one trait is much more expensive to measure.

Back 266

Selection, tandem*

Front 267

The natural or artificial pollination of a female flower with pollen from the same genotype. (See inbreeding, outcrossing, and homozygosity.) The filial generations following selfing are often symbolised by S1, S2.

Back 267

Self pollination (selfing)

Front 268

Genes which are on the sex chromosomes (conifers do not have such chromosomes).

Back 268

Sex-linked genes

Front 269

A term meaning brother or sister. Half sibs have one parent in common. Full sibs have both parents in common

Back 269

Sib-(sibling)

Front 270

A process by which somatic cells are differentiated into somatic embryos.

Back 270

Somatic embryogenesis(SE)

Front 271

The geographic source of cones, seeds and vegetative material (e.g. a seed orchard, cf. origin)

Back 271

Source

Front 272

* Half the inverse of group coancestry. The number of "ideal" trees which have the same gene diversity as the considered population

Back 272

Status number

Front 273

The male (catkin) or female (cone) inflorescence of a conifer, composed of a central axis, scales (sporophylls), bracts, and seeds or anthers. Before and during pollination time they are often called flowers and, for a period thereafter, conelets.

Back 273

Strobilus* (pl. strobili)

Front 274

Subunits of the general breeding population (and other populations in breeding cycle) which are kept unrelated and are genetically at about the same level (differ mainly due to random drift).

Back 274

Sublines

Front 275

Dividing a breeding population into smaller populations. All controlled crosses for forward selection are made within a subline, leading to inbreeding within sublines. Production seed orchards are planted with clones or seedlings from several to many sublines to minimize inbreeding in the production stock.

Back 275

Sublining

Front 276

A technique for cultivation cells, tissues, or organs of plants in a sterile, synthetic medium; includes the tissues excised from a plant and the culture of pollen or seeds.

Back 276

Tissue culture

Front 277

Grafting of scions into the tops of trees (or grafts), usually in the hope of inducing flowering in the scions.

Back 277

Topworking

Front 278

A plant containing DNA that was introduced by gene transfer technique (GE), usually by a transformation event in culture followed by regeneration of a plant. See GMO.

Back 278

Transgenic plant (... tree)

Front 279

- see polyploid

Back 279

Triploid

Front 280

All members of a candidate population equal to or greater than some value in a trait or index are selected, and no members below that value are included in the selected set.

Back 280

Truncation selection

Front 281

In experimental design, refers to an experiment or set of data in which all treatments or treatment combinations are not equally represented. The most common cause of unbalanced experiments is unequal mortality among entries in a test. (See randomised-block design and replication.) Unbalanced selection may refer to that founders or parents are not equally represented among the selections.

Back 281

Unbalanced

Front 282

Differing from the average value. Absence of uniformity, usually referring to lack of genetic uniformity in a population. (See heterozygosity and resilience.)

Back 282

Variability

Front 283

- A statistical measure of variability.

Back 283

Variance

Front 284

* Important genetic variance components are additive variance, dominance variance, epistatic variance

Back 284

Variance components*

Front 285

* A distinctive seedling population or clone, usually one that possesses enough desirable characteristics to be commonly cultivated. In agriculture and horticulture all the plants within a variety would usually be quite uniform genetically. In forestry the term is more loosely used and the variability within a seedling variety is usually much greater. Cf. cultivar, race.

Back 285

Variety

Front 286

Propagation of a plant by asexual means, as in budding, dividing, grafting, rooting, and air layering. (See clone)

Back 286

Vegetative propagation

Front 287

* A populations ability to live, grow and develop. It is affected by physical habitat factors (climate, geology, topography, and aquatic features) and by biotic habitat factors (plant and animal populations and communities).

Back 287

Viability

Front 288

- Pollination by wind-borne pollen. See open pollination.

Back 288

Wind-pollination

Front 289

The product of the fusion of a female and a male gamete in sexual reproduction; a fertilised egg; sometimes also the individual developing from it.

Back 289

Zygote