Registration of Ribstone

Indian Ricegrass Germplasm

Ribstone Indian ricegrass (Achnatherum hymenoides [Roem. & Schult.] Barkw.) germplasm (Reg no. , PI ) was released as a selected class of certified seed (genetically manipulated track). This class of prevariety germplasm is eligible for seed certification under guidelines developed by the Association of Seed Certifying Agencies (2001). Participating in the release are the USDA-ARS, the Utah Agricultural Experiment Station, and Ducks Unlimited-Canada. The intended area of use for Ribstone is on sandy soils of ecoregion #1 (dry mixed grass), characterized by brown chernozem soils (Strong and Leggatt, 1992). This ecoregion occupies an area of southeastern Alberta bordered on the north by about 52^o40' N and on the west by about 112^o25' W, extending into Saskatchewan and Montana.

Ribstone (experimental designation O-4) was selected from T-918, a population collected July 27, 1993 north of Taber, AB, across the Oldman River from Taber Provincial Park (49^o49'15" N 112^o10'06" W). The soil at the collection site is a non-saline (EC=0.2 mmhos cm^-1) alkaline (pH=7.8) sand (96% sand, 2% silt, 2% clay). At the time of collection, this accession was noted as featuring an acute glume pair angle, a trait previously associated with seed retention in the cultivar Rimrock (Whalley et al., 1990; Jones and Nielson, 1992; Jones et al., 1998). Associated plant species at the site were native grasses green needlegrass (Nassella viridula [Trin.] Barkw.), needle-and-thread (Hesperostipa comata [Trin. & Rupr.] Barkw.), blue grama (Bouteloua gracilis [Kunth] Lag. ex Griffiths), western wheatgrass (Pascopyrum smithii [Rydb.] A. Löve), thickspike wheatgrass (Elymus lanceolatus [Scribn. & J.G. Smith] Gould), and junegrass (Koeleria cristata Pers.); shrubs Rosa sp. and Symphoricarpos sp.; and forbs Opuntia sp., Cleome sp., and Dalea sp.

T-918 was established at Evans Farm (Millville, UT) in May, 1994 in an evaluation of 10 Indian ricegrass accessions collected in Alberta. T-918 had the highest seed yield in 1995 and 1996 and the third highest and sixth-highest germination following prechill in 1995 and 1996-harvested seed, respectively. Five of the 10 accessions, including T-918, were advanced to a second trial established in April, 1997 at Greenville Farm (North Logan, UT). From this planting, ten of 123 individual T-918 plants were visually selected in 1999 for acute glume pair angle. Their seed was bulked (O-4) and used to establish a G-1 seed increase at Cornish Farm (Cornish, UT) in April, 2000.

Seed of the G-1 generation will be maintained by the USDA-ARS Forage and Range Research Laboratory, Logan, UT, and seed of G-2 and G-3 generations will be made available to growers by Ducks Unlimited-Canada and the Utah Crop Improvement Association. Seed through the G-4 generation will be eligible for certification, but sale of Ribstone seed beyond generation G-4 is expressly prohibited to limit genetic shift. Small quantities of seed will be provided to researchers upon request to the corresponding author. Appropriate recognition should be made if this material contributes to the development of a new breeding line or cultivar.

T.A. JONES, D.C. NIELSON, S.A. YOUNG, and A. PHAN.

References

Association of Official Seed Certifying Agencies. 2001. Genetic and crop standards of the Association of Official Seed Certifying Agencies. p. 1-12 to 1-14, 2-69 to 2-72. AOSCA, Boise, ID.

Jones, T.A., M.E. Majerus, J.G. Scheetz, L.K. Holzworth, and D.C. Nielson. 1998. Registration of ‘Rimrock’ Indian ricegrass. Crop Sci. 38:539-540.

Jones, T.A., and D.C. Nielson. 1992. High seed retention of Indian ricegrass PI 478833. J. Range Manage. 45:72-74.

Strong, W.L., and K.R. Leggat. 1992. Ecoregions of Alberta. Alberta Forestry, Lands, and Wildlife, Land Information Division, Resource Information Branch, Edmonton, AB.

Whalley, R.D.B., T.A. Jones, D.C. Nielson, and R.J. Mueller. 1990. Seed abscission and retention in Indian ricegrass. J. Range Manage. 43:291-294.