Propagation & Plant Material

This page covers terms used for propagating and breeding plants — cloning and rooting methods, plant genetics vocabulary, and terms describing a plant's reproductive traits.

air layering

A propagation method where roots are induced to form on a stem while it is still attached to the parent plant, by wounding the stem and wrapping the wound in moist medium, before cutting the newly-rooted section away to grow as an independent plant.

autoflower

A plant that shifts from vegetative growth to flowering based on its age or maturity rather than in response to a change in photoperiod, so light-schedule changes don't trigger or delay its flowering the way they would in a photoperiod-sensitive plant.

backcross (BX)

Crossing a hybrid plant back with one of its original parent lines, done repeatedly across generations to shift the hybrid's genetics closer to that parent while retaining a specific trait from the other parent that the breeder wants to keep.

clone / cutting

A piece of stem cut from a mother plant and rooted separately to grow into a new, genetically identical plant. Because it's not grown from seed, its genetics match the parent exactly, unlike a plant grown from that parent's seeds.

cultivar

A plant variety that has been selected or bred for particular traits and is maintained through controlled propagation (cuttings, grafting or controlled seed production) so those traits are reproduced reliably from one generation of plants to the next, rather than drifting over time.

dioecious

A species in which male and female reproductive structures occur on separate individual plants, rather than both being present on the same plant, meaning a male and a female individual are both needed together for seed to form at all.

F1 hybrid

The first-generation offspring produced by crossing two distinct, genetically stable parent lines. Genes from each parent combine in ways that often make F1 plants more uniform in growth than plants bred from later generations, an effect known as heterosis; that uniformity is generally not preserved if F1 plants are bred again.

grafting

Joining tissue from two different plants — a rootstock and a scion — so they fuse and grow as one plant, combining the root system of one with the top growth of the other, often to gain traits neither plant has alone.

hermaphrodite

An individual plant that produces both male and female reproductive structures, either naturally in a normally dioecious species or as a stress response, rather than being exclusively one sex the way the species usually presents itself under stable, unstressed growing conditions.

hybrid vigor / heterosis

The tendency of first-generation hybrid offspring to differ from either parent line in growth rate, size or other traits, a genetic effect arising from combining two distinct parent lines. The effect is most pronounced in the first generation and diminishes in later generations bred from the hybrid.

inbred line (IBL)

A genetically stable line produced by repeatedly breeding closely related plants (often self-pollinating) across several generations, until offspring reliably show the same, consistent traits generation after generation with very little visible variation between any two individual plants in the line.

Indole-3-butyric acid (IBA)

A synthetic auxin commonly used in rooting hormone products because it promotes root initiation at the base of cuttings, making it one of the most widely used compounds in commercial rooting hormone formulations sold to growers around the world today.

landrace

A plant population that has developed its traits through many generations of natural adaptation to a specific local environment and traditional cultivation practices, rather than through deliberate, documented breeding programs aimed at a particular outcome or a single specific trait.

mother plant

A plant kept specifically to provide cuttings for cloning, maintained in vegetative growth rather than allowed to flower, so it continues producing new growth to take cuttings from over an extended period rather than being used for a single one-time harvest.

mutation

A change in a plant's genetic material that alters a trait from what would normally be inherited, which can occur naturally or be induced, and may or may not be passed on to offspring depending on where in the plant it occurs.

Naphthaleneacetic acid (NAA)

A synthetic auxin, similar in function to IBA, used in some rooting hormone formulations to encourage root development in cuttings, and it is sometimes combined with IBA in the same commercial product to broaden its effect across different plant species.

phenotype / genotype

Genotype is the genetic makeup a plant inherits; phenotype is how that genetic makeup is actually expressed in the growing plant's observable traits, which is shaped by both genotype and the growing conditions the plant is exposed to during its life.

rooting hormone

A preparation containing plant hormones, typically auxins, applied to the cut end of a cutting to encourage it to form new roots faster or more reliably than it would unassisted, improving the odds that an individual cutting survives to root.

selective breeding

Choosing which individual plants to breed from, generation after generation, based on which of them show the more desired traits, gradually shifting an entire population's characteristics in that direction over successive generations of controlled crosses between deliberately chosen parent plants.

tissue culture / micropropagation

Propagating plants from very small pieces of plant tissue grown in a sterile nutrient medium in a lab setting, allowing large numbers of genetically identical plants to be produced from a single source plant in a fully controlled, disease-free environment.

variegation

Irregular patches or streaks of a different color, often white or yellow, appearing on leaves due to areas where normal pigment production is reduced or absent, from genetic, viral or environmental causes rather than from a nutrient deficiency in the growing medium.