Air Layering: The procedure to develop roots on undetached aerial parts of a plant by girdling or wounding the area where roots are desired and surrounding the area with rooting medium.
Clone: A population of genetically identical individuals obtained by asexual/vegetative reproduction.
Clonal seed orchard: Seed orchard raised from selected clones propagated by grafting, cutting, air-layering or tissue culture.
Cutting: Detached portion of stem or other plant part which when rooted produces a whole plant.
Extensive seedling seed orchard: Stands established with special stock from a balanced mixture of seeds from at least 60 good parents (preferably of proven superior combining ability) and gradually culled.
Family: A group of individuals that have one or both parents in common.
Flower differentiation: The process during which vegetative tissue forms into reproductive tissue of flowers. The differentiation may occur long time before the actual appearance of the flower buds.
Grafting: Uniting parts of separate individuals by matching their tissue so that union can occur. Commonly an aerial part (scion) is joined with a rootstock.
Incompatibility (graft incompatibility): The failure of the scion and the stock in grafting to form or maintain a union that will result in the desired plant growth.
Ortet: The original plant from which a clone has been derived.
Pollen dilution zone: A zone surrounding a seed orchard or a seed stand in order to protect the orchard from contamination with outside pollen.
Progeny testing: Selection of parent trees based on the performance of their progeny.
Propagule: A plant part, such as a bud, tuber, root, or shoot, used to propagate an individual vegetatively.
Ramet: The individual member of a clone.
Reproductive age: The age at which the tree produces its first fruit crop.
Rouging: Systematic removal of individual not desired for the perpetuation of the population.
Scion: The aerial plant part, often a branchlet, that is grafted onto the root-bearing part (stock, root-stock) of another plant.
Seedling seed orchard: Seed orchard raised from seedlings produced from selected parents through natural or controlled pollination.
Seed orchard: An area where superior pheno-types or genotypes are established and managed intensively and entirely for seed production.
Seed production area: The area of the seed stand.
Seed stand: A group of trees that has been identified or set aside specifically as a seed source. The stand consists of selected trees with desirable characters.
Selection differential: For a given character the statistical difference between the mean of the whole population and the mean of the selected group.
Stock (≈Rootstock): The lower portion of the graft that develops into the root system of the grafted plant. It may be a seedling, a rooted cutting or a layered plant.
Tissue Culture: Propagation of plants from isolated plant cells or small pieces of tissue under controlled conditions in a sterile growth medium.
