Words and Definitions.

Agar

Solidifying substances (pollysaccharides) extracted from redalgae (Rhodophyceae). The dominating pollysaccharides are agarose and agaropectine. The gel solidifies (usually) at about 40°C. Is commonly used as gelling-substance in confectionery, solid media for cell culture (and for cooking). May be found in health food stores.

Asymbiotic

Without a symbiont. (se seed sowing)

Autotroph

An organism cell that harvest energy from inorganic compounds. (Two main types: chemoautotrophs, oxidising inorganic chemicals for energy, and photoautotrophs that depend on light.)

Axenic

From the greek axenos (= inhospitable). Free from the presence of other organisms.

Callus

Lat. Lump; An aggregate of undifferentiated (parenchyma-) cells. Produced naturally as a response to damages in plant tissue. ( Can however be induced with hormones or by the bacteriae Agrobacterium sp.)

Cryptogam

Spore-plant

Cutikula

A layer of cutine, covering the epidermis ('skin') of plant leaves and stem. Is water repelling to keep the plant from loosing water.

Dicotyledons

Dicots. Flowering plants that produce two leaves after germination. The xylem and phloem (the vascular tissue) are arranged in a distinct pattern.

Embryogenesis

Metamorphosis to embryo cell.

Endemic

Existing in a particular geographic area.

Endosymbiont

An organsim (often a fungi) living inside a host. (Cytoplasmatic = in the cell).

Endosperm

The stored nutrients of a seed.

Epiphyte

Organism living on (that's upon) another plant, a host, or some object. The organism doesn't take nutrients from the host.

Explant

A plant part for inoculation onto cell culture medium. (see cloning)

Fanerogam

Seed plant. Flowering.

Habitat

Home, natural growing place.

HEPA

High Efficiency Particulate Air. Bacteria- and spore-safe filter (pore-size ca. 0,3µm). Can filter relatively large amounts of air in a short period of time. (see methods)

Heterotroph

An organism cell living from organic substances. Humans are heterotrophs. Greenplants are generally autotrophs under natural conditions.

Inoculation

To introduce living cells to a nutrient substrate.

In situ

Lat. On spot; In its natural habitat.

In vivo

Lat. In life; on and in living organism

In vitro

Lat. In glass; in a laboratory 'in culture'.

Contaminant

A substance making something impure. We use it analogous to microbe. (May however also be non-living and poisonous or affect e.g. a culture or a plant in a negative (or positive) way.)

Laminar Air Flow Bench/Unit (LAF)

Sterile-bench with walls (like a box with opening in the front) and a constantly blowing stream of filtered-sterilised (bacteria- and spore-free) air, blowing towards the worker(s)..(see methods)

Macronutrients

The nutrients plants need larger amounts of to grow. E.g. nitrogen (N) from nitrates and ammonium-salts, potassium (K), phosphorous (P) which is taken up as phosphate and magnesium (Mg).

MES

2-(N-morfolin)-etansulfonsyra; a pH-controling buffert for cell cultures.

Microbe

Another word for microorganism. (Bacteria, algae (unicellular), microscopic fungi (e.g. jeast) and protozoa. Tens of a millimetre in size (micrometre scale).

Micronutrients

The nutrients a plant only needs small amounts of. E.g. iron (Fe), boron (Br), copper (Cu), zink (Zn), manganese (Mn) etc.

Moncotyledons

Monocots. The group of flowering plants where the seed form one single leaf when germinating. The leaves often have parallell nerves). The phloem and xylem (vacular tissues) are scattered in the stem.

Monphyletic

Greek: Mono = single, phyl = stem. An organsim-group of species that all have the same ancestor is monophyletic.

Monopodial

Greek: Mono = single, podos = foot. Growing-pattern of which the orchid grows from a point with new-production of leaves like in a rosette. e.g. Phalaenopsis, Vanda

Mykorrhiza

Greek: Fungi-root; Mycelium (the fungi) and root (the plant) 'lives in 'co-existance'; exchanging nutrients and various primary- and secondary metabolites. Endotrophic- = mycelia grows into the plant cell, ektotrophic- = mycelia grows around the roots.

Pathogen

A microorganism that is capable to cause disease.

pH

The potential of hydrogen. A measure for the alkalinity or acidity of a substance/solution. The scale is logarithmic and starts at 1 (acid) increasing to 14 (alkaline) where pH=7 is neutral. (The definition is: pH=-lg[H⁺] (or pH=-lg[H₃O⁺]).)

Protocorm

The first tuber-like struktures produced when orchid seeds germinate. Mostly composed of undifferentiated cells. The outer cells contain chloroplasts with chlorophyll. Protocorm grow to form seed plants (seedlings).

Protocorm-like bodies (PLB)

Small swollen tuber, mostly undifferentiated cells. May evolve from orchid cells in tissue-culture. Can be made to produce shoots in vitro with cytokinins and finally become small clone plants.

Spore

Particles produced by certain organisms (fungi and bacteria) and which may develop to new living organisms.

Stigma

Spot at the pistil in fanerogams. Often sticky for the pollen or pollinia to get stuck.

Symbiotic

Living in coexistence with another organism; a symbiont. (see seed sowing )

Sympodial

Greek: sym = with; podos = foot. Growing-pattern where the orchid grows with a rhizome further away from the plant-base; producing new organs (e.g. pseudobulbs) by the side of the plant.

Totipotent cell

A cell that is unifferentiated (non-specific) and which can develop to any specialized tissue-cell. E.g. an embryo; an embryonic cell.

Tryptone

Mostly hydrolysed casein; peptides. Used as a nitrogen source in media for cell culture.

Tuber

Latin, meaning: bulb, knob. Common in anatomical terminology.