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Roath, W.W., R.L. Clark, M.P. Widrlechner, and R.L. Wilson. 1990. Germplasm resources at the North Central Plant Introduction Station. p. 84-90. In: J. Janick and J.E. Simon (eds.), Advances in new crops. Timber Press, Portland, OR.

Germplasm Resources at the North Central Plant Introduction Station

W.W. Roath, R.L. Clark, M.P. Widrlechner, and R.L. Wilson

    1. History
    2. Mission
    3. Facilities
    4. Staff
    5. Financing
    1. Major Collections
    2. Other Collections
  10. Table 1
  11. Table 2
  12. Table 3



The introduction of potentially useful plant species into the United States dates back to the early 19th century when embassies were asked to collect and import these materials. A more organized effort was established when the Section of Seed and Plant Introduction was formed in 1898 within the USDA. No provisions were made, however, to store these materials adequately and much was lost (Wilson et al. 1985).

Forty-eight years later, the four Regional Plant Introduction Stations were established under the Research and Marketing Act of 1946. The North Central Regional Plant Introduction Station (NCRPIS) at Ames, Iowa, which was the first station established, began operation in 1948. The three other regional stations were established at Pullman, Washington; Geneva, New York; and Griffin, Georgia (White et al. 1989). NCRPIS was established as Regional Research Project NC-7, entitled "Introduction, Multiplication, Evaluation, Preservation, Cataloging, and Utilization of Plant Germplasm" (Wilson et al. 1985).


The NC-7 project title describes the mission of NCRPIS, which has the responsibility for the preservation, maintenance and distribution of 1080 species in its present working collection. When an accession is received, that accession is increased, stored, and made available without charge to any requesting scientist or bona fide research agency. The NCRPIS collection includes more than 23,800 accessions. Accessions are evaluated for morphological and physiological characteristics and those data are made available to the user through the National Plant Germplasm System's (NPGS) database, the Germplasm Resources Information Network (GRIN) (Perry et al. 1988). In addition, the NCRPIS Research Unit assists in evaluation of accessions, in new crop development, and in studies related to maintenance of the collection.


NCRPIS is located on land provided by Iowa State University. The Station includes farm offices, laboratory space, greenhouses, seed processing space, seed storage, machinery and equipment storage, and a machine shop, as well as land for seed increase and research plots. The professional staff, graduate students, and research technicians are provided offices, research laboratories, and greenhouses on campus.


Present staff includes both Federal (USDA-ARS) and State employees in several categories:

Administrative Staff: USDA-supported Coordinator and Secretary.

Professional Staff: USDA-supported Research Agronomist, Research Entomologist, and Horticulturist, and State-supported Plant Pathologist.

Curatorial Staff: Five State-supported Curators with responsibilities for the following crops, amaranth and miscellaneous legumes, maize, sunflower, vegetable crops, Brassica and grasses.

Support Staff: The Farm Superintendent, two technicians (maintenance and seed), and two clerks; a data processor, and a maize technician, are all State employees. There are USDA-supported Research Technicians for the Agronomist, Entomologist, and Horticulturist, as well as a bee technician. Additional part time or temporary employees (usually students) are hired as necessary. In addition a few graduate students work on germplasm related projects.


NCRPIS is financed by three agencies. Federal funds account for about 75%, and regional research funds allocated by the directors of the 12 north central states (Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin) total 17%. The Iowa Agriculture and Home Economics Experiment Station provides 8% of the support through in kind contributions.


Major Collections

Table 1 lists the genera that account for 85% of the more than 23,800 accessions at NCRPIS. This table also lists the total number of accessions in the present collection, and the number of accessions available for distribution for each genus. The number of available accessions changes from year to year with changes in amount of seed increase, in germination, and demand for seed; as well as new introductions.

Other Collections

Several major crop collections are kept at other north central locations such as soybeans at the University of Illinois, Urbana-Champaign, potatoes at Sturgeon Bay, Wisconsin, and flax at North Dakota state University, Fargo, North Dakota. Additional genera at NCRPIS are represented by only a few accessions, and include wild relatives of crops, that have shown potential as future crops, or are primarily of botanical interest (Table 2).


Species are assigned to one of the Regional Plant Introduction Stations (RPIS) after consultation by the Coordinators. Factors such as area of adaptation, current interest in a crop, and number of accessions are considered before a species is assigned to a specific RPIS. These factors have resulted in shifts in assignment over the years.

Accessions are acquired by NCRPIS by several means. These include plant explorations, foreign or domestic, which may be conducted by NCRPIS personnel, or by arrangement with other collectors. Seed can be requested by NCRPIS from other agencies through the Germplasm Services Laboratory (GSL) at Beltsville, Maryland, or by the GSL staff. Direct contact with other researchers and through exchange with other genebanks is another means of acquisition.

All accessions in NPGS are recorded, assigned plant inventory (PI) numbers, and all of their pertinent data recorded into GRIN.


Every effort is made to maintain the genetic integrity of the original accession after it reaches NCRPIS. Seed increase is usually required before an accession is available for distribution. Additional seed increases are made only after the distribution lot becomes less than a critical quantity (usually 1000 seeds), or germination is reduced to less than 70%. All distribution seed lots are germinated after increase and every five years thereafter. Association of Official Seed Analysis (AOSA) germination rules are used whenever possible (AOSA 1976). All seeds are stored in clear containers in refrigerated storage at 4°C and 35-40% relative humidity.

Pollen control is accomplished for cross pollinated crops by caging increase plots or bagging individual plants. Pollination is accomplished by introducing honey bees, and/or house flies, into the cages of wild sunflower, umbels, cucumber, muskmelon, and many herbaceous ornamentals (Ellis et al. 1981). Other pollinator species, such as bumble bees and leafcutting bees, are used for specialized crops such as Cuphea. Crops such as maize, Cucurbita, and cultivated sunflower, are isolated by bagging flower parts and hand pollination. Pollen control techniques vary with the species. Seed increase population sizes vary with the species but, whenever possible, they are kept sufficiently large to maintain genetic integrity (Clark 1989 and NCRPIS 1988).

Self-pollinated crops are generally increased without providing isolation. They require smaller population sizes than cross pollinated crops if they are homozygous. Where the degree of outcrossing within an accession is variable or unknown, increases are isolated by cages without pollinators.

Seedlings of most small seeded crops are started in the greenhouse and transplanted to the field. Large seeded crops, such as maize and sunflower, are direct seeded with a tractor drawn planter. Harvest is accomplished by hand, and plant material is dried at 27deg. to 32°C. Fruits from vine crops are hand harvested, seed is removed from the fruit and dried under similar conditions. Dried seeds are generally threshed by hand or by hammer mill, and then cleaned with desk top clipper cleaners and/or air column separators. Hand picking is sometimes required for final cleaning. After cleaning, seed is inventoried and placed in storage. Seed of each accession is sent to the National Seed Storage Laboratory at Fort Collins, Colorado for inclusion in the base collection.

Some crops or accessions from various crops need to be increased at sites other than NCRPIS. Tropical maize, for example, which has a short day-length requirement for flowering is increased at the USDA Agriculture Research Service Tropical Research Station at Mayaguez, Puerto Rico. This station is also used as a winter nursery for sunflowers.


Seed of available accessions are distributed to requesting scientists free of charge. For most species, 100 seeds per accession are distributed. The small seed of Amaranthus, Brassica, Cuphea, and some grasses are distributed in lots of 200 or less depending upon seed availability. In special cases, such as evaluation requiring larger seed amounts, additional seed can be sent if reserves are adequate. Seed requests can be made by letter, telephone, or computer linked to GRIN. The use of GRIN requires the requester to obtain the proper GRIN access codes and procedures (NCRPIS 1988 and Perry et al. 1988).

In 1987, 19,689 seed lots were distributed worldwide. About half of the 13,473 U.S. requests were from privately supported research projects, and about half of those requests came from the North Central Region. Foreign scientists received 6216 seed lots (NCRPIS 1988). Table 3 shows the number of crop distributions.


Accessions are evaluated for various traits to increase their usefulness in crop improvement. A list of the more important traits (descriptors) is developed by the Crop Advisory Committees (CAC) responsible for each crop. When feasible, the U.S. descriptors are kept consistent with those established by the International Board of Plant Genetic Resources (IBPGR). Many of the morphological descriptors are measured by the curator at the time of seed increase.

Much of the evaluation is for pest resistance. The NCRPIS pathologist and entomologist are responsible for some of this work. Since it is not possible for NCRPIS personnel to evaluate all pests that may affect a crop, researchers at other institutions work cooperatively with NCRPIS personnel to evaluate for pests, and morphological and physiological descriptors for which they have expertise. All these data are entered into GRIN.

Special funds have been provided to NCRPIS by USDA-ARS to evaluate certain characters in sunflower and sugar beets. Evaluation for adaptation of woody ornamental species to conditions in the North Central Region is an ongoing project, with 32 active trial sites. (Wilson et al. 1985).


Jones (1983) defined enhancement as transferring useful genes from exotic or wild germplasm into agronomically acceptable backgrounds. Enhancement is being applied at NCRPIS in transferring fruit rot resistance into cucumbers and the domestication of Cuphea.

Several problems pertaining to maintenance of germplasm at NCRPIS are being addressed by the Research Unit. Examples of past and current research include: studies of insect pollination in cages of sunflower (Collison and Wilson 1985) and Cuphea, studies to determine rearing techniques for insect pests needed for evaluation (Wilson and McClurg 1986), storing and longevity of Cuphea seed, storing sunflower pollen (Roath et al. 1988), and adapting wild mint family species to use as bee pasture (Widrlechner 1987).


The Germplasm Resources Information Network (GRIN) is the information data bank common to the NPGS (Perry et al. 1988). This data bank provides uniform capability for storing and retrieving, passport, inventory, germination, order processing, and descriptor data on all material in the NPGS. These data can be accessed by the user community directly if the user has a computer and a modem along with the proper access codes. In this way, the user can search for the germplasm material of interest and order that material electronically. However, the traditional means of phone and mail requests are still the major means of sending requests for information or securing germplasm. Information on securing access to GRIN can be obtained by writing:

Mr. J.D. Mowder
GRIN Database Manager
Bldg. 001, Rm. 130, BARC West
Beltsville, MD 20705


Table 1. NCRPIS crop genera, accessions, and available accessions.

Genus Total Accessions Available Accessions
Zea 6617 5003
Cucumis 3525 2399
Brassica 3496 1565
Helianthus 3016 897
Amaranthus 2630 721
Beta 1021 462
Panicum 964 775
Setaria 938 867
Cucurbita 816 511
Daucus 625 397
Melilotus 575 485
Cuphea 360 81
Woody ornamentals (511 spp.) 1090 296
Herbaceous ornamentals (154 spp.) 285 102

Table 2. Genera at NCRPIS with less than 300 accessions/genus.

Genus No. of Accessions Genus No. of Accessions Genus No. of Accessions
Grasses and Field Crops
Agrostis 193 Glyceria 6 Tetrachne 1
Apera 6 Helictotrichon 9 Tricholaena 14
Briza 4 Nardus 2 Tridens 4
Calamovilfa 3 Phleum 2 Tripsacum 5
Echinochloa 67 Schedonnardus 1 Urochloa 1
Amphicarpa 1 Dalea 13 Petalostemon 3
Coronilla 91 Galega 13 Tetragonolobus 20
Fruits and Vegetables
Asparagus 144 Pastinaca 34 Sium 1
Cichorium 193 Petroselinum 139 Spinacia 264
Ferula 2
Oil and Special Crops
Agastache 21 Echinops 2 Nepeta 1
Alliaria 1 Elsholtzia 1 Ocimum 87
Alyssum 1 Enarthocarpus 1 Oenothera 1
Ammi 2 Eruca 149 Onosma 1
Anethum 73 Eryngium 7 Origanum 8
Arctium 1 Eupatorium 2 Orlaya 2
Berteroa 3 Euphorbia 18 Osteospermum 1
Bifora 18 Foeniculum 12 Oxalis 2
Biscutella 1 Glaucium 2 Perilla 19
Bupleurum 2 Goldbachia 1 Perovskia 2
Calamintha 1 Guizotia 1 Picris 4
Camelina 9 Helenium 1 Pimpinella 17
Cardamine 1 Hyoscyamus 1 Pycnanthemum 17
Carum 4 Hyssopus 1 Rhaponticum 4
Caucalis 1 Iberis 2 Rionosciadum 1
Celosia 6 Isatis 2 Salvia 6
Centranthes 1 Lallemantia 1 Schlectendalia 2
Chamaepeuce 1 Lappula 2 Sideritis 2
Chenopodium 59 Lapsana 4 Sigesbeckia 1
Christolea 1 Leonotis 1 Sinapis 20
Cnicus 2 Lepidium 69 Stachys 1
Coriandrum 46 Levisticum 1 Stenachaenium 3
Crambe 158 Limnosciadium 1 Symphytum 4
Cynoglossum 1 Linum 9 Tephrosia 14
Ducrosia 1 Lobularia 1 Thalictrum 21
Echinacea 1 Lunaria 1 Thlaspi 3
Madia 1 Trachyspermum 1
Monarda 20 Vaccaria 8
Mosla 1 Vernonia 15
Abies 1 Fendlera 1 Phellodendron 6
Acer 64 Fittonia 1 Phlox 1
Adonis 4 Fontanesia 1 Photinia 3
Ailanthus 3 Forestiera 2 Physocarpus 5
Alcea 9 Forsythia 3 Picea 4
Alchemilla 3 Fraxinus 32 Picris 1
Alnus 16 Geranium 2 Pinus 28
Althaea 2 Ginkgo 1 Platanus 2
Amelanchier 8 Gleditsia 2 Polygonum 1
Amorpha 12 Gymnocladus 2 Populus 5
Ampelopsis 4 Gypsophila 7 Potentilla 13
Anemone 2 Hamamelis 1 Prinsepia 1
Antirrhinum 1 Helianthella 1 Prunus 13
Aronia 4 Helichrysum 1 Pterocarya 2
Artemisia 1 Hemerocallis 1 Pteroceltis 1
Asimina 2 Hesperis 1 Pterostyrax 1
Asphodeline 2 Heteropappus 1 Purshia 1
Asphodelus 1 Hippophae 3 Pyrus 3
Baileya 1 Holodiscus 4 Quercus 13
Baptisia 2 Hovenia 2 Rhamnus 11
Begonia 2 Hydrangea 8 Rhododendron 12
Berberis 1 Hypericum 3 Rhodotypos 4
Betula 32 Ilex 2 Rhus 22
Bryonia 1 Iliamna 2 Ribes 11
Buckleya 1 Impatiens 2 Robinia 4
Buxus 1 Iris 1 Rochelia 1
Calendula 14 Jamesia 2 Rosa 43
Callicarpa 8 Juglans 2 Rubus 1
Caltha 1 Juniperus 40 Ruscus 1
Campanula 5 Kalmia 1 Salix 45
Campsis 2 Kalopanax 1 Sambucus 3
Caragana 7 Kitaibelia 1 Sanvitalia 12
Carpinus 15 Knautia 1 Sapium 1
Catalpa 1 Kohleria 2 Scilla 1
Catananche 1 Kolkwitzia 1 Securinega 1
Ceanothus 7 Laburnum 4 Shepherdia 3
Celastrus 1 Lapeirousia 1 Sibiraea 1
Celtis 12 Larix 5 Simsia 1
Cephalotaxus 2 Lavatera 8 Smilax 1
Cercis 22 Ledum 1 Sorbus 29
Cercocarpus 5 Ligustrum 26 Spergula 1
Chaenomeles 1 Lilium 3 Sphaeralcea 2
Chamaebatiaria 1 Lonicera 13 Spiraea 6
Chamaecyparis 1 Lythrum 1 Staphylea 17
Cheiranthus 2 Maackia 1 Styrax 1
Chilopsis 1 Maclura 4 Symphoricarpos 1
Chrysanthemum 85 Mahonia 1 Symplocos 1
Cistus 1 Malope 1 Syringa 6
Clematis 4 Malus 8 Tetradymia 1
Coleus 10 Malva 9 Thuja 7
Consolida 4 Malvastrum 1 Tilia 7
Cornus 39 Menispermum 1 Tithonia 4
Corylopsis 1 Metasequoia 1 Tripterygium 2
Cotoneaster 20 Mimulus 3 Tulipa 3
Crataegus 19 Morus 1 Ulmus 14
Cupressus 7 Myrica 1 Undetermined 4
Cytisus 2 Mytilaria 1 Verbena 1
Daphne 1 Nyssa 3 Viburnum 27
Delphinium 10 Onoseris 1 Viola 2
Dianthus 25 Ostrya 13 Weigela 14
Dipteronia 1 Oxydendrum 1 Wisteria 1
Duchesnea 3 Paeonia 1 x Sorbocotoneaster 1
Elaeagnus 5 Parthenocissus 1 Xanthoceras 2
Eucommia 2 Passiflora 1 Yucca 8
Euonymus 33 Paxistima 1 Zelkova 2
Evodia 3 Peganum 1 Zinnia 32
Exochorda 2 Penstemon 41 Ziziphus 1
Fallugia 1 Peperomia 1
Petteria 2

Table 3. Number of packets or plants distributed from NCRPIS, July 1987 to July 1988.

Distribution (no.)
Genus Seed packets Plants
Zea 1806
Cucumis 5258
Brassica 2440
Helianthus 1239
Amaranthus 199
Beta 72
Panicum 96
Setaria 71
Cucurbita 137
Daucus 303
Melilotus 58
Cuphea 70
Woody ornamentals 21 1217
Herbaceous ornamentals 60 1
Other 6944

Last update February 12, 1997 by aw