ARS Germplasm Holdings of Grasses and Legumes

By Kevin Jensen

Location

U.S. Department of Agriculture, Agricultural Research Service, Forage and Range Research Laboratory, Utah State University, Logan, UT 84322-6300

Loans

Seed requests handled by Dr. Richard Johnson, Plant Germplasm Introduction and Testing, USDA-ARS, PWA, Johnson Hall, Room 59, Washington State University, Pullman, WA 99164-6402. Small seedlots of breeding lines and clonal material are available upon request.

Associated
libraries

Plant Germplasm Introduction and Testing Office, Pullman, WA

Number of
accessions

3,500

Types

Pseudoroegneria deweyi

Curators

Home page

Content

Triticeae collection. Tribe Triticeae is a relatively small but important group of species. It contains some of the most important cereal crops (wheat, barley, and rye) and many important forage grasses, including crested wheatgrass, tall wheatgrass, intermediate wheatgrass, bluebunch wheatgrass, Great Basin wildrye, and Russian wildrye. Depending on the taxonomic treatment used, there are approximately 325 species in the tribe, of which about 75 percent are perennials that inhabit much of the world's temperate and subarctic regions.

In addition to their value as forage and conservation grasses, the perennials in this tribe are a vast genetic reservoir for cereal improvement. The perennial habit, disease and insect resistances, and cold, drought, and salt tolerances are some characteristics of Triticeae grasses that plant breeders would like to incorporate into wheat and barley. The wheatgrasses and their perennial relatives are also valuable in basic research concerning genetics, cytogenetics, evolution, speciation, taxonomy, polyploidy, and interspecific hybridization. These grasses are valuable research tools because of their extreme morphological variation, varied ecological requirements, wide geographical distribution, diverse modes of reproduction, forms of polyploidy (they have all forms), wide range in chromosome number, large chromosomes, and unusual ability to hybridize with other species.

Since 1936, the Agricultural Research Service (ARS) has maintained a cooperative rangegrass project on breeding and cytogenetics with the Utah Agricultural Experiment Station at Logan. The project focuses on wheatgrasses and their closest relatives because of their importance on western rangeland. In 1962, Dr. Douglas Dewey began assembling perennial Triticeae germplasm from all parts of the world. The collection now contains over three-fourths of the known perennial species. The collection has been accumulated from three primary sources: (1) the USDA Regional Plant Introduction Station at Pullman, WA; (2) scientists in the United States and other countries; and (3) plant exploration by scientists of the Forage and Range Research Laboratory (FRRL) of the USDA-ARS, Utah State University. Foreign plant exploration has been a major source of germplasm (table 1). However, maintained at the FRRL is a large collection of native grass species within the tribe.

The seed portion of the collection now contains over 3,100 accessions of species representing all genera and over 500 seed lots of interspecific and intergeneric hybrids within the tribe. Within the collection, there are 400 accessions of Agropyron (4 species), 1,022 accessions of Elymus (118 species), 106 accessions of Elytrigia (4 species), 117 accessions of Hordeum (29 species), 240 accessions of Leymus (28 species), 31 accessions of Pascopyrum (1 species), 86 accessions of Psathyrostachys (4 species), 232 accessions of Pseudoroegneria (11 species), 220 accessions of Thinopyrum (15 species), and over 30 accessions representing Haynaldia, Heteranthelium, Hordelymus, Secale, Taeniatherum, and Australopyrum. The seed portion of the collection is maintained in four large refrigerators where the seed is stored at 30 °F and 16-20 percent relative humidity.

Native Grass Collection. Assembly of the native grass seed collection began in 1986 and now includes 956 accessions of 11 grasses of economic or potential economic importance. Taxa include Oryzopsis hymenoides (389 accessions), Leymus cinereus (193 accessions), Pseudoroegneria spicata (117 accessions), Elymus elymoides (68 accessions), E. lanceolatus subsp. wawawaiensis (50 accessions), E. lanceolatus subsp. lanceolatus (42 accessions), Stipa robusta (42 accessions), S. viridula (33 accessions), L. triticoides (13 accessions), E. trachycaulus (6 accessions), and S. nelsonii (3 accessions). Accessions of all taxa except O. hymenoides and L. triticoides are refrigerated. These two species are maintained at room temperature because of their characteristically high seed dormancy. Fifty-seven breeding populations, many of which represent hybrids, are also available. Table 2 lists domestic plant-collection trips from which accessions were derived.

Table 2. Domestic plant-collection expeditions (1986-1995) conducted
by the Forage and Range Research Laboratory for perennial
grasses and other species

Legume Collection. The legume living collection consists of 258 accessions of alfalfa (Medicago spp.), 70 accessions of birdsfoot trefoil (Lotus spp.), and a breeding population of kura clover (Trifolium ambiguum). Approximately 250 additional seed lots of Medicago spp. are maintained in M.D. Rumbaugh's original seed inventory. The following germplasm is maintained in the seed inventory: U 2951 and U 2954 Foxtail clover (T. rubens), U 2936 Scarlet Globemallow (Sphaeralcea coccinea), U 2982 Munroe Globemallow (S. munroana), U 2956 Chiment sweetvetch (Hedysarum semenowi), U 2953 Mongolian sweetvetch (H. mongolicum), U 2923 Austrian flax (Linum austriacum), U 2955 Spanish sweetvetch (H. humile), U 2921 Flatpea (Perennial Sweetpea) (Lathyrus latifolius), U 2922 Crown vetch (Coronilla varia), and U 2962 Siberian Sainfoin (Onobrychis sibirica)

Small quantities of seed from breeding lines and clonal materials are available at the FRRL. However, requests for large quantities of seed for raw germplasm should be made through the Plant Germplasm Introduction and Testing Office, Pullman, WA. Taxonomic identifications are made for grasses within the Triticeae tribe.

The collections housed at FRRL are used to define genomic and phylogenetic relationships among component species. Many of these species, particularly grasses, are used in crosses to make interspecific and intergeneric hybrids. For the past 30 years, phylogenetic relationships within these collections have been derived using geographic distribution, morphological variation, chromosome pairing, hybrid fertility, and recently molecular techniques. Perhaps the most important use of these collections is in the development of new and improved plant materials for land revegetation and restoration, soil stabilization, pastures, and low-maintenance turf.

Recent plant releases include the following:

• Hycrest--an improved cultivar of crested wheatgrass that was developed from a hybrid between an induced tetraploid of 'Fairway' (Agropyron cristatum) and the natural tetraploid Standard (A. desertorum)

• Bozoisky-select--an improved cultivar of Russian wildrye released in 1985. The parental germplasm for this cultivar was derived from an introduction (PI 406468) from the former Union of Soviet Socialist Republics (USSR).

• NewHy-RS Hybrid wheatgrass--a cross between quackgrass (Elytrigia repens) and bluebunch wheatgrass; released as a cultivar in December 1989. This new hybrid combined the vigor, productivity, salinity tolerance, and persistence of quackgrass with the drought resistance, caespitose growth habit, seed quality, and forage quality of bluebunch wheatgrass.

• Vavilov--a Siberian wheatgrass released in 1994. The parental germplasm for the cultivar Vavilov was derived from accessions originally received from the N.I. Vavilov Research Institute of Plant Industry, Stavropol Botanical Garden of the former USSR, Eskisehir Plant Breeding Station, Turkey, and from selections of the cultivar P-27.

• Douglas--the first hexaploid (2n=42) cultivar of crested wheatgrass to be released in North America. It was released in 1994. The breeding population was derived from hybrids between an accession from the former USSR (PI 406442) and three accessions from Iran (PI's 401076, 401080, and 401085) and one accession from Turkey (PI 173622).

Germplasm releases include the following:

• SL-Germplasm--derived from an amphiploid hybrid (2n=42) between the diploid (2n=14) form of bluebunch wheatgrass (PI 232132, originally collected in Utah) and thickspike wheatgrass (PI 236663, an accession from Nevada).

• ARS-2892 Munroe Globemallow--a native, xerophytic, perennial herb widely distributed in communities in which shadscale, juniper, desert shrub, and mountain brush grow. ARS-2892 is a selected ecotype originating from seed collected from naturally occurring plants growing on the Hyrum Lake Dam, Cache County, UT.

• ARS-2936 Scarlet Globemallow germplasm--a native, perennial, herbaceous species widely distributed in the Rocky Mountains and Great Plains rangelands of the western United States. Seeds of ARS-2936 were harvested from a native stand in northern Idaho in 1987.

• ARS-2678 Kura Clover germplasm--originated from 51 seed accessions obtained by D.R. Dewey and A.P. Plummer from the Stavropol Botanical Garden and originated from the Caucasus Mountain area of the former USSR.