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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Agricultural Genetic Resources Preservation Research » Docs » Plants » Pages » NLGRP FAQ


About the facility:

About the collections:

General preservation questions:


What are genetic resources? Genetic resources are living material such as crops, livestock, related species, rare and endangered varieties and breeds that include genes, genetic combinations (a.k.a. genotypes) or genetic frequencies that give diversity to future varieties or breeds.  In agriculture, genetic resources are used by breeders to increase yields and stress tolerance, improve nutrition, and add value, beauty, flavor, and adaptability.

What is germplasm? Germplasm is a set of propagules that carries the desired genetic resource (i.e. genes, genetic combinations or gene frequencies).

What is an accession? An accession is a genetically unique plant sample from a particular geographic location.  At NLGRP, an accession may be a bag of seeds, plant tissue cultures, or buds from twigs of fruit crops.  NLGRP sometimes stores more than one sample of a particular accession.  When samples are regrown or reproduced, the subsequent generation has the same accession number as the parent sample.  The new sample has an inventory number that identifies the generation number. 

What is a propagule? A propagule is a tissue, organ or plant part that can be regenerated into a whole plant (i.e. seeds, cuttings and budwood).

What is genetic diversity? Genetic diversity is variation in life that is heritable. Modern crops or livestock breeds may have a low amount of diversity because of repeated selection for desirable traits and widespread use of few individuals or varieties.  Populations become diverse through the processes of mutation and sexual reproduction.  Natural selection acts on this diversity to favor the changes that enable the best survival in a particular environment.  Populations that have a lot of genetic diversity can survive dynamic environments better than populations that have low genetic diversity.  Genetic diversity is what enables breeders to improve plant varieties and animal breeds. 

What is a clone?  A clone is a group of genetically identical cells descended from a single common ancestor; one or more organisms descended asexually from a single ancestor; one that is an exact replica of another (Webster II. The Riverside Publishing Company, 1984).

What is cryopreservation?  Cryopreservation is a process of cooling cells or various kinds of tissues to temperatures below zero to slow down effectively life processes without damage to the material. Plant tissues or plant cells are usually cryopreserved at liquid nitrogen (-196oC) or vapor of liquid nitrogen (ca. -156oC).

What are plant tissue cultures?  Plant tissue cultures are plant tissue, cells or plant organs maintained or propagated in vitro under aseptic conditions on sterile culture medium.  This method of plant propagation is referred often as micropropagation. Plants derived from one original propagule (plant, tissue or cell) are clones.

What is a recalcitrant seed? A recalcitrant seed, in contrast to most crop seeds, is a seed that cannot survive drying and so cannot survive in the freezer. Preservation of recalcitrant seeds requires a procedure that prevents damage by drying or freezing. This has been accomplished in several species by excising the growing part of the seed, optimizing the water content, and cooling very rapidly. Recalcitrant seeds are frequently produced by temperate-zone forest trees, riparian species, and plants from the tropics. Examples of recalcitrant seeds are oak seeds, wild rice, and citrus.

Why is the NLGRP located in Fort Collins, Colorado? The dry climate was a primary reason that the USDA National Seed Storage Laboratory (NSSL) was located in Fort Collins, CO. With an average relative humidity of about 30%, little effort was needed to adjust seed moisture content to the optimum level needed for long-term storage. In the 1950s a Colorado State University professor, Dr. D.W. (Scotty) Robertson, was very active in promoting germplasm preservation. A barley breeder, Dr. Robertson, argued that a base collection for genetic resources should be established and worked to have the Laboratory built on the Colorado State University campus. The Beet Sugar Development Foundation also supported these efforts.

What is the NLGRP capacity? The NLGRP has capacity to store between one and 1.5 million accessions, depending on the size of the propagule, in storage vaults cooled to -18oC (conventional storage). In addition, the NCGRP has a 220 cryotank capacity, with each cryotank holding about 3,000 seed and 70,000 semen accessions.

How safe are the collections?  The facility has protected access to all work areas in the building.  The storage areas , including the seed cold vaults and cryogenic room, are further restricted by added security with limited access of only a few individuals, additional locked doors, security cameras, and coded information on sample bags.  The vault area is fortified against tornadoes and floods and there are backup mechanical systems.

Can anyone get seeds from NLGRP? Distributions are made for research purposes from the NPGS sites located around the US.

Where does the germplasm come from and who donates it? Germplasm comes from all over the world and it is donated by collectors, breeders or experts in systematics who locate material with unusual or interesting traits that may eventually be useful in agriculture. For example, a collector may find an apple with unusual flavor or a wheat landrace that is resistant to aphids. Most of the germplasm for agricultural crops comes from the area where that crop evolved. This area, known as the Center for Diversity, is believed to have the highest genetic variability in the smallest geographic area.

Does NLGRP save endangered plant species? In collaboration with conservation groups, we store seeds of endangered species. This activity can preserve the remaining genetic diversity of an endangered species until it is reintroduced into native habitats.

How large is the NLGRP plant collection? There are more than 500,000 accessions in the collection. Each accession contains about 3,000 to 5,000 seeds, depending on the reproductive biology of the species.

How many species are in the NLGRP plant collection? About 12,000. Changing needs for US agriculture and landscapes will lead to an inevitable increase in the numbers of species collected and stored at NLGRP.

How do I request germplasm? Search and request germplasm using GRIN-Global.

What is the best way to store seeds? Allow seeds to dry for a few weeks in a place with about 20% relative humidity.  Then store seeds in vapor-proof containers such as a glass jar or sealed moisture-proof bag in a cold place like a home freezer.

How long can seeds survive in storage? Seed longevity depends on storage conditions and seed quality. We expect most undamaged seeds that are properly dried to survive about a hundred years in conventional storage (-18C) and about a thousand years under cryogenic (liquid nitrogen) conditions.

What is the oldest living seed? The most reliable studies show some seeds in soil at archeological sites surviving for 100 to 1,700 years. (e.g. Odum 1965. Germination of ancient seeds: floristical observations and experiments with archaeological dated soil samples. Dan. Bot, Arkiv 24(2):1-70; Shen-Miller, J., Mudgett, M.B., Schopf, J.W., Clarke, S., and Berger, R. 1995. Exceptional seed longevity and robust growth: Ancient sacred lotus from China. American Journal of Botany).

How long does DNA last? DNA, the genetic code, found in all life, is a very stable molecule. Fragments that are thousands of years old have been found in archeological artifacts, especially if the artifacts have been kept dry or free from microbes that cause decay.

Can I plant seeds from an apple I really enjoyed? You can plant seeds from that apple and get a tree in about 5-10 years, but the fruit from the new tree will not be the same as the apple that you enjoyed. This is because fruit quality is specific to the mother plant, and the mother tree and the offspring tree are genetically different. Most fruit crops must cross-pollinate to produce seeds. For fruit crops, the same genetic line is usually maintained by grafting budwood from the mother plant onto a rootstock or rooting stems that are cut from the mother plant.

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