REGISTRATION OF 'CD-II' CRESTED WHEATGRASS
Crop Sci. 37:1023
K. H. Asay,
N. J. Chatterton, K. B. Jensen, R. R-C. Wang, D. A. Johnson, W. H. Horton, A.
J. Palazzo, and S. A. Young
'CD-II' (Reg. no. CV-24, PI 594024 crested
wheatgrass is a 10-clone synthetic derived from the cultivar Hycrest (1), which
is a hybrid between induced tetraploid Agropyron cristatum (L.) Gaertner and
natural tetraploid Agropyron desertorum (Fisch. ex Link) Schultes. CD-II was
developed by a research team at the USDA-ARS Forage and Range Research
Laboratory, Utah State University, Logan, UT, and released 25 January 1996 in
cooperation with the Utah Agricultural Experiment Station and the USDA Natural
Resources Conservation Service. CD-II was evaluated as Hycrest-II.
A breeding program was initiated in 1985 to
improve the Hycrest breeding population. The base population was derived from
100 clonal lines, which were selected from a Hycrest foundation seed-increase
block consisting of 40,000 spaced plants. Selection was based primarily on
vegetative vigor and absence of purple leaves during the early spring,
tolerance to diseases and insects, and leafiness.
The 100 clonal lines were evaluated a second
time in a 10-replicate crossing block for the same vegetative characters as
well as for individual seed weight and emergence of polycross seedlots from
deep seedings. Polycross progenies from 30 selected clonal lines were bulked in
equal quantities to form a breeding population, which was advanced through two
additional breeding cycles of selection for leafiness, vegetative vigor, and
seedling vigor. Polycross seed from 10 clonal lines selected from the final
breeding cycle was bulked to form breeder seed.
CD-II has been distinguised from Hycrest on
the basis of Random Amplified Polymorphic DNA (RAPD) fingerprinting profiles.
It was selected for improved leafiness and produces significantly more forage
under cold temperatures in the growth chamber than Hycrest. Seedling vigor of CD-II
on a field site near Logan, UT was significantly greater than Hycrest. Under
more xeric conditions, ease of stand establishment, forage yield, and
persistence were comparable to Hycrest and were significantly greater than the
cultivars Nordan and Fairway, particularly during, and immediately following,
establishment. The cultivar produces from 670 to 900 kg seed ha-1 on
sites receiving 400 to 450 mm of annual precipitation with no supplemental
irrigation. CD-II produces abundant forage during the spring and early summer,
and it is recommended for semiarid range sites in the Intermountain Region and
Great Plains receiving 200 to 450 mm annual precipitation at altitudes up to
2200 m. When drilled under dryland range conditions, a seeding rate of 7 to 9 kg
ha-1 is recommended.
Breeder, foundation, and certified seed
classes of CD-II will be recognized. Breeder seed will be maintained by the
USDA-ARS Forage and Range Research Laboratory at Logan, UT. Rights for
production and sales of foundation and or certified seed will be awarded.
Protection has been applied for (Application No. 9600240) under the Plant
Variety Protection Act of 1994 with the requirement that seed of CD-II can be
marketed only as a class of certified seed. Genetic material of this release
will be deposited in the National Plant Germplasm System where it will be
available for research purposes, including development and commercialization of
new cultivars.
References
Asay, K. H., D. R. Dewey, F. B. Gomm, D. A.
Johnson, and J. R. Carlson. 1985. Registration of 'Hycrest' crested wheatgrass.
Crop Sci. 25: 368-369.
K. H. Asay, N. J. Chatterton, K. B. Jensen,
R. R-C. Wang, D. A. Johnson, and W. H. Horton, USDA-ARS Forage and Range
Research Laboratory, Utah State Univ., Logan, UT 84322-6300; and S. A. Young,
Plants, Soils, and Biometerorology Dep., Utah State Univ., Logan, UT
84322-4820. Cooperative investigations of USDA-Agricultural Research Service
and the Utah Agricultural Experiment Station, Logan, UT 84322-4820. Approved as
Journal Paper No. 4902. Registration by CSSA