Biomedical Engineering Reference
In-Depth Information
entries for overall biomass yield, averaging 22,800 kg ha
1
per year over five
cuttings, in a comparison of 21 warm-season and six cool-season grasses [
1
].
Because of its tall stature and caespitose growth habit, tall wheatgrass provides
excellent nesting and cover for upland game birds. Its seeds remain on the plant
relatively well, providing feed for birds during periods of deep snow cover. The
species has shown to have value in plantings as a barrier against wind and drifting
snow [
102
].
Genetic Resources
Tall wheatgrass is genomically related to the intermediate wheatgrass complex.
Intensive cytogenetic studies have established that it is essentially an
autodecaploid, comprising five sets of genomes, designated E
e
or E
b
[
106
]. The
E
e
genome originated from the diploid
T. elongatum
and the E
b
genome originated
from
T. bessarabicum
. Tall wheatgrass has proven to be valuable in wide hybrid-
ization programs to transfer genes conditioning resistance to salinity, drought, and
disease to wheat [
35
,
107
]. Molecular genetic markers developed from
T. intermedium
(E
e
E
e
E
b
E
b
StSt),
T. bessarabicum
(E
b
E
b
), and
T. elongatum
(E
e
E
e
) should also be useful for tall wheatgrass [
84
].
Breeding Strategies/and Traits
The gene base of tall wheatgrass included in North American breeding programs is
relatively narrow, with most cultivars tracing to one or two plant introductions.
“Largo” the first cultivar to be released was derived from PI 109452, an accession
collected by the Westover-Enlow expedition in Turkey. It was originally increased
at the USDA-SCS nursery at Albuquerque, New Mexico, and the Utah Agricultural
Experiment Station at Logan, Utah, cooperatively with USDA-ARS and released in
1937 [
91
].
Alkar, which is the widest used cultivar, was selected at the USDA-SCS Plant
Materials Center at Pullman, Washington, and released in 1951 [
91
]. Its parental
germplasm was derived from PI 98526, an accession obtained from the USSR via
the N. I. Vavilov Institute of Plant Industry in 1932. Alkar is widely used in the
Pacific Northwest and the Intermountain Region for pastures in wet, alkaline
conditions [
102
,
108
].
The cultivar “Jose” was released in 1965 and has been used for pasture and hay
in irrigated areas of New Mexico and Colorado at elevations up to 2,300 m, as well
as on range sites where alkali and salinity prohibit the use of other productive
grasses. It is reported to be more acceptable to grazing animals than cultivars such
as Alkar and Largo [
109
].
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