Glossary

  • A

  • B

  • C

  • D

  • E

  • F

  • G

  • H

  • I

  • L

  • M

  • N

  • O

  • P

  • R

  • S

  • T

  • U

  • V

  • W

A

abiotic Non-living factors that influence plant growth, function and survival (for example, soil, water, amount of sunlight, nutrients, etc.).
accession A collection occurring within one plant population at one location that may be collected over several consecutive days. In botanical garden databases, an accession is given a unique number that can be tracked through time.
acclimatize Harden off a plant so that it can survive under low humidity conditions.
adaptive capable of genetic change by natural selection.
adaptive monitoring plan Long-term plan for measuring attributes such as survival, growth, and reproduction of a reintroduced population that can evolve or change when answers to initial questions (or hypotheses) are met and new questions arise across time.
admixture Interbreeding between two or more previously isolated populations, sometimes resulting in introducing foreign or unadapted genes.
adventitious shoot A shoot that arises from a point that is not the shoot tip (for example a bud at a leaf axil).
allele DNA found on one location on a chromosome that corresponds to a trait. Depending upon the plant and the number of paired chromosomes it has, one- to- many alleles may be responsible for traits related to appearance, chemistry, or growth. In genetic tests, the number of unique alleles is one measure of genetic diversity.
ambient conditions The relative humidity and temperature of the room. When processing seeds for long-term storage, it is a good idea to check the room temperature and humidity. Seeds will have best chance for long-term survival if processed at temperatures below 25oC. Humidity levels can be taken below ambient levels when using a desiccator.
apical meristem Growing tissues at the tip of a shoot.
artificial selection The process of modifying organisms by selection in breeding controlled by humans (for example, choosing a plant with numerous fruits and removing low fruit-producing plants in a breeding program will artificially select for fruit production).
asexual In plants a form of reproduction that does not involve pollen or flowers and therefore new individuals formed by this method have the same genetic makeup (unless unusual mutations occur). Types of asexual reproduction in plants include producing corms or bulbs (as in lilies) or producing roots along a stem that gets buried (as in willows).
auxins A plant hormone that causes the elongation of cells in shoots and is involved in regulating plant growth.
axillary bud A bud that grows from the axil of a leaf or node and has the potential to form stems and branches with leaves or reproductive shoots with flowers.
axillary shoot The stem that grows from an axillary bud at the axil or base of a leaf.

B

backup facility A second seed bank or nursery where a representative portion of an accession can be stored.
biodiversity, or biological diversity The variety of life. This recent concept includes different levels of biological organization. It considers the diversity of species of plants and animals that live in one place, their genetic variability, the ecosystems that these species form part of, and the landscapes or regions where the ecosystems are located. It also includes the ecological and evolutionary processes that occur at the level of genes, species, ecosystems, and landscapes.
bioinformatics An interdisciplinary field of science that combines biology, computer science, mathematics, and statistics to analyze and interpret biological data.
biome Distinct communities of animals and plants that have formed in response to a shared physical climate and occur across continents (for example, tundra, temperate forest).
biotic Living factors that influence plant growth, function and survival (for example, predators, fungi, pollinators).
black box storage The seeds in the seed bank are stored under "black box" arrangements, meaning that overseers of the seed bank will never open or test any of the seed packages.
breeding system The method by which a plant can successfully produce seeds. Plants have three basic breeding systems: outbreeding or outcrossing, where pollen from a different individual is needed to fertilize the egg of the maternal plant to produce seeds successfully; selfing or self-fertilization, where pollen from the same individual can fertilize the egg and produce seeds; or apomixis, where seeds can be set without fusion of gametes.

C

clonal Type of asexual reproduction in plants that produces new individuals with the same genetic makeup as the mother plant (unless unusual mutations occur). Examples include producing corms or bulbs (as in lilies) or producing roots along a stem that gets buried (as in willows).
common garden An experimental technique wherein plants from more than one location are grown together in a single (hence common) garden. This method allows researchers to determine if differences observed in the geographically separated populations have a genetic basis.
competition An interaction between living organisms or the same or different species for a common resources, territory, or mate that occurs in a limited supply.
congeners (congenerics) Members of the same genus.
Conservation Collection An ex situ (offsite) collection of seeds, plant tissues, or whole plants that supports species’ survival and reduces the extinction risk of globally and/or regionally rare species. A conservation collection has accurate records of provenance, maternal lines differentiated, and diverse genetic representation of a species’ wild populations. To be most useful for species survival in the wild, a conservation collection should have depth, meaning that it contains seeds, tissues or whole plants of at least 50 unrelated mother plants, and breadth, meaning it consists of accessions from multiple populations across the range of the species. Conservation collections should have tests of initial germination and viability, cultivation protocols developed, and periodic testing of long-term viability. A conservation collection differs from a horticultural collection, which may have few genetically unique individuals, or is solely comprised of unusual appearing forms.
conservation introduction Defined by IUCN as the intentional movement and release of an organism outside its indigenous range.
Conservation Status A formal designation of endangered or threatened status at a state, federal, or international level.
conservation translocation A definition coined by IUCN to describe intentional movements of organisms within the species’ indigenous range (reinforcement or augmentation of existing population and reintroduction into an area once but not currently occupied by the species) and movements outside of indigenous range including conservation introductions, comprising assisted colonization and ecological replacement.
conservation value The degree to which an action might contribute to reducing a species’ extinction risk.
conspecifics Individuals of the same species.
controlled rate cooling Precise and steadily paced reduced temperatures imposed on plant tissues prior to cryopreservation in liquid nitrogen. The intention of the process is to avoid injuries to cells and increase survival after exposure to liquid nitrogen.
conventional storage Storage at freezer temperatures (–18oC + 3oC or 0oF + 5oF).
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cross-pollination The transfer of pollen from the anther of a flower of one plant to the stigma of the flower of another plant of the same species.
cryogenic storage Storage below –130°C in specialized containers holding liquid nitrogen.
cryopreservation Preserving tissues by storing in liquid nitrogen at temperatures below –130°C.
cultivars A plant variety that has been produced in cultivation by selective breeding (for example, a “Champagne” mango).
cultivated setting A place for growing plants with altered amounts of water, changed light conditions, and reduced exposure to predators than the natural conditions experienced by the wild population.
curation package A separate envelope containing one to a few seeds of each maternal line in an accession that can be used to test germination and longevity of viability after storage over time.
cytotypes A characteristic of a cell. Organisms of the same species with different cytotypes have different numbers of chromosomes.

D

Darwin Core A body of standard terms intended to facilitate the sharing of information about biological diversity by providing reference definitions, examples, and commentaries (http://rs.tdwg.org/dwc/).
desiccation The process of removing moisture for the purpose of preservation.
desiccators Sealable enclosures containing desiccants used to equilibrate the moisture of seeds prior to long-term storage. Desiccators create and maintain dry environments to ensure stable moisture content.
deterministic event A predictable or known event (for example, cold temperatures in winter north of the equator are predictable).
Differential Scanning Calorimetry (DSC) A 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. This is relevant to seed storage in that lipid composition within a seed can be measured using this technique without harming the seed.
dioecy Having male and female flowers on different individuals.
DNA banking Long-term storage of an individual’s genetic material. In plants, leaves are common tissue that can be stored.
dormant a state of slowed activity, in seeds, alive, but not actively growing
drying agent Any substance that can remove moisture from seeds. Examples include salts and silica gel.
drying temperatures The temperature at which seeds should be held while drying to the target moisture content. Safe drying temperatures to maximize seed longevity are below 25oC.

E

ecological Pertaining to the ecology of an organism, the interactions of living organisms with each other and with their environment.
ecoregion A geographically defined area with distinctive ecology that may change with changing global conditions.
ecotypes A distinct form or race of a plant occupying a particular habitat.
edaphic endemics Plants that grow only on a specific soil type.
effective population size (Ne) The number of individuals that contribute genes to succeeding generations. This number is typically less than the number of individuals in the whole population, because not all individuals may be reproductive.
ex situ Offsite, away from the wild population, usually referring to collection held in nursery or botanic garden.
Exceptional Species Non-orthodox species that cannot be conserved long-term using conventional seed banking methods. This includes species with few or no seeds available for banking, species with seeds that are intolerant of desiccation and freezing, or seeds that can tolerate drying, but not freezing, or species that may only tolerate storage at –20oC for less than 10 years. 
explant Tissue transferred to or from a tissue culture medium.
extirpation Local extinction, where a species ceases to exist in a chosen geographic area, while it still exists elsewhere.

F

F1 generation First generation.
F2 generation Second generation.
FAO Food and Agriculture Organization of the United Nations
fecundity The number of seeds or asexual propagules produced by an individual plant or population.
field genebank Plants grown in the ground for the purpose of conservating genes. In botanical gardens, display collections of trees, shrubs, herbs can be considered field genebanks.
flow cytometry A laser or impedence-based technology employed to count or sort cells. This can be used to analyze the ploidy levels or numbers of chromosome sets of individual plants in a population.
foil envelopes Protective packaging that maintains stable moisture levels within the package and is recommended for long-term seed storage.
founder effect The genetic composition of the individuals that create a new population.
founder(s) The individual(s) that starts a new population.

G

gene flow, or migration Any movement of individuals, and/or the genes from one population to another. It can be described as limited, meaning that the individuals living near one another are closely related (for example, monkshood), or extensive, meaning that it is possible to find traces of genes in an individual that lives very far away (for example, wind-pollinated plants).
genetic diversity Variation in the DNA sequence between distinct individuals of a given species (or population). The degree of genetic diversity can be compared between individuals or populations. Capturing the breadth of existing genetic diversity is the goal of a conservation collection.
genetic drift Variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes as individuals die or do not reproduce.
genetic erosion Loss of genetic diversity. For an endangered species with a limited gene pool loss of individuals equates to loss of genes and alleles represented for the species.
genetic rescue Increasing genetic diversity from infusing new genes into a population. If population is inbred, this practice may increase chances that some plants will survive.
genetic structure A measure of the differences across and within populations of a species. Populations of a species may have similar or different genetic composition. Measures of this pattern have conservation implications for providing source material for a conservation translocation.
genome A complete set of genes or genetic material present in a cell or organism.
genomic studies evaluations of the specific arrangement of DNA on the chromosome.
genotype The genetic constitution of an individual (genotyping is determining the genetic constitution of an individual).
georeferenced Points taken with GPS that can be used to locate a plant again. Herbarium specimens and seed collections when georeferenced can contribute greatly to our understanding of how plant populations may change in the future.
germination When a radical emerges from a seed. Percent germination is the percentage of seeds in a test sample that germinate in a given time. ((Seeds germinated by dayx/Total number of seeds tested) X 100 = % germination).
germplasm Living seeds or tissues from which plants can be grown.

H

hand-pollination (hand pollinated) A process where pollen is manually and deliberately transferred to the receptive portion of a flower (the stigma). This technique is often used to control the parentage and to maximize pollen transfer in hopes of achieving fertilization and good seed set.
herbarium vouchers A specimen of a pressed plant that is deposited and catalogued for future reference.
hybridization Cross species fertilization. In the context of conservation, it is often undesirable to have hybridization occur in a cultivated or wild setting, as the more common parent will likely swamp the genepool of the rare species.

I

immature seeds Seeds with underdeveloped embryos. To determine whether a seed is fully developed may require cutting it open and looking under a microscope.
immigrate To move into an area. In a context of conservation collection health, it is sometimes necessary to allow genes or seeds from a wild population to move into an ex situ population.
in situ In wild habitat.
in vitro Micropropagation; plant tissues grown on nutritional medium in a sterile humid glass or plastic container.
inbreeding Mating between closely related individuals. Over many generations, genetic disorders may arise.
inbreeding depression Reduced fitness of progeny resulting from breeding of related individuals.
intact embryos A complete, undamaged embryo.
inter situ In between ex situ (offsite and fending for itself) and in situ (in wild habitat), the inter situ conservation collection has diverse genetic representation and supplemental care. The term was first used to refer to the restoration of declining species in areas that are outside their current range but within historical ranges, inferred from paleoecological studies, but is now used to describe a semi-wild setting for ensuring species’ survival.
intermediate (seed) Share functional characteristics with recalcitrant seeds and should be stored in liquid nitrogen. When dried to 50%–75% RH, they have a longer shelf-life than storage at 15%– -35% RH levels recommended for orthodox seeds. Seeds age faster when stored at conventional freezer temperatures compared to refrigerated temperatures. Faster aging might be detected within days, months or years, making it difficult to identify which species’ seeds are intermediate. Longevity of seeds increases with drying and cooling (as with orthodox seeds), but seeds still age rapidly during conventional storage and will die within about 5 years.
internal seed moisture Water content of a seed. This can be measured using a process that will destroy the seed: weighing a seed, drying it until there is no change in its mass, and calculating water content mathematically. Obtaining individual seed moisture content is recommended. For very small seeds, this requires a very precise balance.

J

K

L

loci The location of a particular gene on a chromosome.
long-term storage At least 5 years. Note that the length of time a species’ seed can stay alive in dry, cold storage will vary across species.
long-term storage packages Foil package containing CPC seed collections with maternal lines separated for a single accession (collection of seeds from a single wild population on a single date) that is intended to stay in storage for at least 5 years.

M

Material Transfer Agreement The agreement that CPC has with the Resources Preservation Unit - Seeds of the National Laboratory for Genetic Resources Preservation, Fort Collins, Colorado, to store national collection rare plant seed accessions in long-term black-box storage.
Material Transfer Research Agreement The agreement that CPC has with the Plant Germplasm Preservation Research Unit of the National Laboratory for Genetic Resources Preservation, Fort Collins, Colorado, to conduct research on and store national collection rare plant seed accessions long-term.
maternal lines The offspring (seeds or plants) from a single mother plant are distinguished with unique identifying number, stored in a separate package, and labeled if grown in a nursery. Knowing the number of maternal lines in a conservation collection is an estimate of the genetic diversity represented.
maternal plants Individual plants producing seeds. Keeping track of seeds from each maternal plant allows for estimates of genetic diversity in a collection and allows for maintaining even representation of maternal lines while growing the accession in the garden’s nursery or reintroducing to the wild.
mating system The way that plants produce seeds. Some plants can produce seeds in multiple ways, while others are restricted to a single mating system. The types of mating system include outcrossing or cross-pollination (a flower receives pollen from another plant of the same species), autogamy or self-fertilization (a flower receives pollen from the same plant) and apomixis (asexual reproduction without fertilization that is only possible with evolution of a modified flower). Mixed mating systems, in which plants use two or even all three mating systems, are not uncommon.
meristem Growing tip of plant.
metapopulation A group of spatially separated populations of the same species that interact (for example, the interaction can be pollen or seeds moving between plant populations).
metapopulation dynamics A change across time within a group of separated but interacting populations that influence the overall persistence of a species.
microcatchments Small, localized wells or depressions around a plant that serve to gather and hold water. These are recommended for plants or seeds installed in dry habitats.
microhabitat(s) Very localized abiotic (soil, light, and moisture) and biotic (associated plants, insects, and other animals). The nature of a microhabitat may greatly influence seedling and adult plant growth and survival. See also microsite(s).
micropropagation In vitro; plant tissues grown on nutritional medium in a sterile humid glass or plastic container.
microsatellite markers Genetic markers consisting of a series of short repeating base pairs of DNA that are variable within populations and can be used to identify individuals or species, or evaluate structure and gene flow between populations.
microsite(s) Very localized abiotic (soil, light, and moisture) and biotic (associated plants, insects, and other animals). The nature of a microhabitat may greatly influence seedling and adult plant growth and survival. See also microhabitat(s).
mitigation In the context of CPC protocols, mitigation is a legal term for an action that is taken to offset the adverse impacts of development on U.S. listed species. For example, a parcel land where a species occurs may be preserved as mitigation for developing a portion of the species’ habitat.
moisture content The percentage of water in seed. %Moisture content = ((Weight of fresh sample – Weight of dry sample)/ weight of fresh sample) x 100. The target moisture for storing seeds equals no more than 25% RH (lower risk of failure) and no less than 10% RH (higher risk of failure) at the intended storage temperature.
molecular (studies) Genetic studies.
monoecy Having flowers with only one sex (male or female) or flowers of both sexes carried on a single plant.
morphological Pertaining to the form or structure.
MSBP Millennium Seed Bank Partnership
multiple years testing the tooltip, can delete after
mycorrhizal inoculum A fungi that forms a symbiotic relationship with a plant’s roots and increases water and nutrient absorption.

N

natural selection The process whereby organisms better adapted to their environment tend to survive and produce more offspring than those that are not well adapted.
neighborhood size The local area within which most matings occur.
niche space The ecological space occupied by a species (Hutchinson definition); an ecological role (Grinnel definition); a species’ response to and effect on environment (Elton definition).
nodes Intersection along a stem holding one or more leaves, as well as buds which can grow into branches which in turn may produce leaves, cones, or flowers.
non-orthodox species See exceptional species.

O

obligate mutualists Organisms that are required to rely on one another for survival.
obligate outcrosser Pollen from a different plant (not self) is required for successful seed set.
open pollination (open pollinated) Allowing flowers to be pollinated naturally by wind, insects, or birds. In studies, open pollination is used as a comparison to hand pollinated trials to determine the highest seed set that could be expected in a flower.
orthodox seed Seed capable of being dried to internal seed moisture of less than 12% water, stored at freezing temperatures, and surviving.
outbreeding A condition where flowers of one plant receives pollen from another plant of the same species.
outbreeding depression Low fitness of progeny resulting from mating between two genetically distant (and usually physically distant) plants.
outcrossing The form of plant reproduction that requires pollen from another plant of the same species to form seeds.
outplanting Transplanting from a botanical garden nursery (ex situ setting) to a wild setting for purposes of reducing the extinction risk of a species and allowing persistence in a natural setting.

P

patch dynamics Spatial and temporal changes within and among patches of vegetated or bare spaces that make up a landscape.
perennial A plant that lives for many years.
phenological Pertaining to phenology. With changing climate, plants growing in certain locations have changes in the phenology.
phenology The timing of key life history events in a plant’s life, such as flowering or fruiting.
phenotype The measurable appearance of a trait.
plantlet Young or small plant.
ploidy The number of sets of chromosomes in a cell.
ploidy analysis Examination of the number of chromosomes in an individual plant or across plants in a population and would be performed if differences in ploidy are expected.
ploidy level A description of the number of chromosomes in an individual, population or species. For example, diploid organisms have pairs of chromosomes. In plants, multiple sets of chromosomes are possible, even within a single population, especially as a result of hybridization.
pollination mechanism The method in which pollen is transferred from anthers to the stigma of same or different flowers. Wind, insects, or birds are the most common pollinating mechanisms.
polyploidy variation Differences in the number of sets of chromosomes present in a species or population.
population A group of potentially interbreeding individuals that share a common ancestry or gene pool.
population dynamics The study of changes in size and age structures of populations over time.
population persistence A measure of effective conservation is to have a population grow and reproduce sustainably over time in a wild setting.
population reproductive output Total seeds produced in a population within one growing season.
population size The number of individual plants of all ages in the population.
primary facility The seed bank or botanical garden where the accession is stored. A duplicate of the same accession is stored at a backup facility.
provenance The place of origin.

Q

R

randomly chosen A formal process for selecting an unbiased sample.
recalcitrant seed Seed incapable of conventional storage due to desiccation intolerance and/or freezing intolerance.
reciprocal transplant An experimental method which involves introducing plants from each of two or more environments into the other(s). The method can be used to test whether differences in appearance, for example, between populations have a genetic versus environmental basis.
recovery staff Personnel of U.S. Fish and Wildlife Service working toward ending extinction of federally listed species.
recovery team Experts from U.S. Fish and Wildlife Service, academia, and conservation organizations who voluntarily review a species conservation status and make recommendations for its recovery.
reference populations The population used as a basis for comparison. In the context of reintroduction, the growth and survival of plants in the wild population can be compared to the reintroduced population as a measure of success.
reintroduction science Growing body of experimental evidence related to enhancing a rare species survival by human action to increase the number of individuals or populations in a natural setting.
reintroduction(s) intentional movement of species into habitat it previously occupied.
representative genetic diversity Best captured by making seed collections across the spatial extent of the population, from plants that are not physically close to one another, and from plants of all sizes and levels of seed output.
rescue collections When an entire population is threatened, it may need to be removed from its location and brought to an ex situ or offsite facility for care.

S

safety duplication A half of a collection that may be stored in a second location as a precaution against losing the accession due to natural catastrophe.
sample A portion of the population that is collected at one time. CPC recommends collecting a sample of no more than 10% of the seeds produced within a population in a growing season.
sampling Strategy to use to collect the representative genetic diversity in a population.
self-compatibility A condition where a flower of an individual can receive pollen from itself and set good seeds.
self-fertilizing Pollen from one plant fertilizes a flower of the same plant such that good, viable seed results. This technique is often used experimentally to determine whether this is possible for a species.
self-incompatibility A condition in flowering plants that prevents self-fertilization and thus encourages seeds to be set when pollen from a different unrelated individual fertilizes the eggs of the mother plant. One of the mechanisms that causes this is a special allele (SI) that prevents pollen from germination on the receptive surface of the flower called the stigma.
selfing Pollen from one flower fertilizes the same flower and successfully sets seed.
sensitive animal species Those with protected legal status by state or federal agency.
Sentinel Plant Network A collaboration between the National Plant Diagnostic Network and the American Public Gardens Association to improve the ability to detect and respond quickly to serious plant pests and diseases.
sequencing Refers to genetic procedure to determine the composition and order of genes of an individual as in genotyping.
silica gel A granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate that can be used to dry seeds.
specialist pollinators Organism adapted in structure and behavior to gather and transfer pollen to flowers of one or a few related species of plant.
stochastic event Unpredictable or chance event.
symbiont An organism living in close association with another.

T

target storage RH The relative humidity sought to maximize seed longevity while seeds are held in storage at a particular temperature.
taxon A taxonomic group of any rank, such as a species, family, or class. Sometimes this term is used rather than species, because it will encompass varieties and subspecies.
taxonomic ambiguity Unknown or undetermined genus and species designation of an organism.
Thumb Rules or Hundred Rule Developed by J. F. Harrington (1916–2002) at UC Davis in the 1950s to guide storage conditions for maintaining seed viability, state: “Seed lifespans double for every 1% decrease in water content or 10oF decrease in temperature.” According to Harrington’s “Hundred Rule,” seed viability can be maintained [for 5 to 10 years] if the sum of the relative humidity and temperature (in oF) is less than 100.]
tissue culture Growing cells in an artificial medium. In plant conservation, the cells may be whole seeds, spores, or meristems and the medium is usually some derivation of agar.
transects A line of known length used as a way to monitor vegetation.

U

USFWS U.S. Fish and Wildlife Service.

V

viability Ability to live and survive successfully.
Viability Testing Systematically checking and counting the number of live seeds in a sample.
vital rates Measure of change that influence population growth (for example, birth rate, survival of an age class from one year to the next, death rate).
vitrification To make liquids solid without forming crystals, a “glassy state.” Forming ice crystals inside plant cells can be deadly. When a solid state can be achieved without ice, vitrification is the term used to describe ice free cryopreservation.
voucher specimen A pressed plant sample deposited in an herbarium for future reference.

W

water vapor transmission rate The amount of water lost or gained across a storage container membrane in a given period of time.
Weed Risk Assessments A science-based evaluation of the potential of a plant species to establish, spread, and cause harm in a region. Several weed risk assessments exist for different regions of the U.S. (for example, Hawai’I; https://sites.google.com/site/weedriskassessment/home, California: http://www.cal-ipc.org/solutions/research/riskassessment/, and Florida: http://edis.ifas.ufl.edu/ag376).
wild population The plant population that exists in a natural setting. Note that the wild or natural setting may not be pristine.
wild species A species that is usually found growing in the wild without human intervention (i.e., in situ). We might also say they are from ‘natural populations.’ Usually we distinguish wild and domesticated species, the latter has been changed by humans usually for the purposes of cultivation. Arboreta and botanical gardens often grow or store individuals collected in the wild. We would call this “ex situ.”

X

Y

Z