NEBRASKA
UNIVERSITY OF NEBRASKA AND THE USDA-ARS
Department of Agronomy, Lincoln, NE 68583, USA.
P.S. Baenziger, R.A. Graybosch (USDA-ARS), D.R. Shelton, K.S.
Gill. T. Clemente, K. Arumuganathan, T. Weeks (USDA-ARS), R.C.
French (USDA-ARS), D.C. Stenger (USDA-ARS), and C.J. Peterson
(USDA-ARS).
1998 crop conditions.
The 1998 Nebraska wheat crop was estimated at 2,302,000 MT (84,600,000
bu), which represented a 3,160 kg/ha (47 bu/acre) state average
yield on 730,000 harvest hectares (1,800,000 harvested acres).
Winter wheat was planted on 770,000 hectares (1,900,000 acres).
This crop had a record yield per hectare and was larger than the
1997 crop (70,300,000 bu harvested from 1,900,000 acres with a
37.0 bu/acre yield average) and the 1996 crop (73,100,000 bu harvested
from 2,150,000 acres with a 34 bu/acre yield average), but smaller
than the 1995 crop of 86,100,000 bu (41 bu/acre). With these high
yields, the protein content was lower than normal (generally 11.5
to 12.0 %). Arapahoe continued to be the most popular and widely
grown variety (28.3 % of the state) in 1998. To put Arapahoe's
acceptance in perspective, it was grown on more acres in Nebraska
than varieties developed by all other states and commercial seed
companies combined. Alliance was the second most widely grown
variety followed by Centura and Niobrara.
New germ plasm.
Culver is a HRWW developed coöperatively by the Nebraska
Agricultural Experiment Station and the USDAARS. Culver was selected
from the cross 'NE82419 / Arapahoe', which was made in 1987. The
pedigree of NE82419 is 'Trapper // CMN / OT /3/ CIMMYT / Scout
/4/ Buckskin sib / Homestead'. Culver is an F3-derived line that
was selected in the F4 generation. Culver was released primarily
for its superior adaptation to and good disease resistance in
dryland agriculture production systems in southcentral and southwestern
Nebraska. Culver is moderately resistant to stem rust (contains
Sr6 and Sr24, and other unnamed resistance genes)
and leaf rust (similar to Arapahoe and most likely contains Lr16)
and susceptible to WSBMV, Hessian fly, BYDV, and WSMV. Culver
has a moderately low grain-volume weight, better than that of
Alliance, but less than those of Arapahoe, Pronghorn, and Rawhide.
The overall end-use quality characteristics for Culver should
be acceptable to the milling and baking industries. Culver is
recommended for growing in southern and westcentral Nebraska.
In these areas, Culver is a good replacement for Alliance, because
it has a longer coleoptile, better leaf rust resistance, grain-protein
content, and grain-volume weight. The cultivar is genetically
complementary to 2137, Alliance, Jagger, Niobrara, Pronghorn,
and Windstar. Culver is not complementary to Arapahoe, Niobrara,
and Vista. Like Arapahoe, Culver also seems to have a growth pattern
where early spring drought can lower its performance.
Wesley is a HRWW developed by the USDA-ARS (Dr. C. J. Peterson's
leadership) and the Nebraska Agricultural Experiment Station.
The cultivar will be coreleased with South Dakota Agricultural
Experiment Station. Wesley is a high-yielding, semidwarf wheat
with adaptation characteristics similar to 2137 and is particularly
well suited for production in southeast Nebraska and under irrigation.
Wesley has superior straw strength, a short coleoptile, and a
heading date similar to that of Scout 66. The winter hardiness
of Wesley is superior to that of Scout 66 and TAM-107. Wesley
is postulated to carry Sr6 and Sr17 and also has
resistance to WSBMV, WSSMV, and is tolerant of acid soils. The
name was chosen to honor the late Dr. John Wesley Schmidt, former
wheat breeder at the University of Nebraska.
Four experimental lines (Nuplains, NE93496, NE93613, and NE 94479)
are under large-scale increase for possible release in 1999. In
addition, NE93405 has been held over for a third year of testing
before possible release in 1999. NE93405 and NE93496
(NE85707/Thunderbird) are sister lines and are Thunderbird
derivatives with along coleoptile, good winter hardiness, good
test weight, large kernels, and very strong straw strength (NE93496
having the better standability). NE93613 is a sister line to Culver
with a medium-length coleoptile, good winter hardiness, average
test weight, medium kernels, and moderately strong straw strength.
NE94479 was derived from the cross 'Arapahoe / Abilene // NE86488'.
The pedigree of NE86488 is 'Colt /3/ WRR 5* / Agent // Kavkaz'.
NE94479 has good winter hardiness, average test weight, medium
kernels, and moderately strong straw strength. As opposed to Arapahoe
and Culver, it seems to perform well despite spring droughts.
Nuplains is a HWWW developed by the USDAARS (Dr. C. J. Peterson's
leadership) and the Nebraska Agricultural Experiment Station.
The line is derived from the cross 'Abilene / KS831872', where
the pedigree of KS831872 is 'Plainsman V // Newton / Arthur 71',
a high protein selection. Nuplains is a dual-purpose wheat, suitable
for both bread and noodle making.
Wheat transformation and tissue culture studies.
A. Mitra, T. Clemente, S. Sato, P. S. Baenziger, R. French, and
T. Weeks.
Numerous transgenic plants were created using the particle bombardment
technique, and progress was made developing an Agrobacterium-facilitated
method. One of the main disease-resistance efforts currently being
studied is the 2-5A system, a key research area of Dr. Mitra,
which may provide broad-spectrum resistance to RNA virus (such
as WSMV). Mr. Todd Campbell, a graduate student, is genetically
characterizing 2-5A transgenic plants. One of his more interesting
findings is that that although co-transformation is common (in
this research, genes on three plasmids were inserted), co-insertion
is less common (i.e., the three plasmid did not always insert
at the same site). The importance of this finding is that it may
be possible to have genes of interest (there are two main genes
in the 2-5A system) co-insert, but have selectable marker genes
(often antibiotic resistance genes) insert at different genome
locations that can later be bred out of the populations. Some
consumers are concerned with antibiotic resistance genes in food.
The wheat transformation team at the Plant Transformation Core
Research Facility at the University of NebraskaLincoln employs
both microprojectile bombardment and Agrobacterium-mediated
transformation protocols for the genetic engineering of wheat.
Transformation efficiencies range from 26 % and 0.10.7 % on an
explant/plant basis for the microprojectile and Agrobacterium-mediated
protocols, respectively. Our future plans include further genetic
characterization of transgenic plants, developing optimized transgenes
for expression in wheat, and adding possible fungicidal genes
as part of the scab initiative research.
Wheat quality research.
R.A. Graybosch, D.R. Shelton, and Gang Guo.
Functional properties of waxy wheat samples were analyzed. Wheat
a -amylase activities, kernel weights and hardness values, flour
Rapid Visco Analyser parameters, and falling number values were
determined. These results were compared with those of the control
wheats with nonwaxy starch that were planted at the same location.
The comparisons showed Rapid Visco Analyser parameters, such as
peak time (temperature), holding strength (trough), breakdown,
setback, and final viscosity, varied significantly between the
waxy and control samples (p-value = 0.0001). Waxy wheat had much
lower pasting (gelatinizing) temperature, lower peak time (temperature),
lower holding strength, lower setback, and final viscosity than
the controls but had much higher breakdown. The falling number
values of waxy wheat were much lower (about 70 seconds) than those
of the controls (about 500 seconds). However, the a -amylase activities
indicated that the variations in pasting properties were mainly
due to the fact that the waxy starch activities of waxy wheats
and control samples were approximately equal.
The T1AL·1RS wheat-rye chromosomal translocation originally
found in Amigo wheat has resistance genes for stem rust, powdery
mildew, and greenbug biotypes B and C, but also has a negative
effect on wheat processing quality. Recently, a second T1AL·1RS
translocation with Gb6, a gene conferring resistance to
greenbug biotypes B, C, E, G, and I, was identified in the wheat
germ plasm line GRS1201. A secalin of Mr 70 kD was found in the
Amigo T1AL·1RS but did not occur in the GRS1201 T1AL·1RS.
Polymorphisms detected by PCR primers derivedfrom a family of
moderately repetitive rye DNA sequences also differentiated the
two translocations. No differences in grain yield or grain and
flour quality characteristics were observed when lines carrying
1RS from Amigo were compared to lines with 1RS from GRS1201. Hence,
differences in secalin composition did not result in differential
quality effects. When compared to sister lines with T1AL·1RS
derived from the wheat cultivar Redland, lines with the GRS1201
had equal grain yield, but produced flours with significantly
shorter mix times, weaker doughs, and lower SDS sedimentation
volumes.
Personnel.
Dr. C. J. Peterson resigned from the USDA-ARS to accept a position
as wheat breeder at Oregon State University. Dr. R. Graybosch
will assume the role of coördinator for the USDA-ARS Hard
Winter Wheat Regional Program. Mr. Delton Dovel retired after
30 years of dedicated service to the wheat improvement efforts.
Mr. Pat Tenopir accepted a position with the Foundation Seed Division.
Mr. Mitchell Montgomery joined the wheat improvement project in
May, and Mr. Chris Hoagland joined the wheat improvement project
in August as their successors. Dr. Mohammed Maroof Shah successfully
completely his Ph.D. and accepted a postdoctoral position at Iowa
State University.
Publications.
Baenziger PS, Moreno-Sevilla B, Peterson CJ, Shelton DR, Baltensperger
DD, Haley SD, Nelson LA, McVey DV, Watkins JE, Hatchett JH, and
Schmidt JW. 1998. Registration of 'Windstar' Wheat. Crop Sci 38:
894-895.
Delwiche SR, Graybosch RA, and Peterson CJ. 1999. Identification
of wheat lines possessing the 1AL·1RS or 1BL·1RS
wheat-rye translocation by near-infrared reflectance spectroscopy.
Cereal Chem (In press).
Graybosch RA, Peterson CJ, Hareland GA, Shelton DR, Olewnik MC,
He H, and Stearns MM. 1999. Relationships between small-scale
wheat quality assays and commercial test bakes. Cereal Chem 76:(In
press).
Graybosch RA, Lee J-H, Peterson CJ, Porter DR, and Chung OK. 1999.
Genetic, agronomic and quality comparisons of two 1AL·1RS.
wheat-rye chromosomal translocations. Plant Breed 118:(In
press).
Graybosch RA, Peterson CJ, and Chung OK. 1999. Quality effects
of rye (Secale cereale L.) Chromosome arm 1RL transferred
to wheat (Triticum aestivum L.). J Cereal Sci (In press).
Wesenberg DM, Baenziger PS, Rasmusson DC, Burrup DE, and Jones
BL. 1998. Registration of 88Ab536-B barley germplasm. Crop Sci
38:559.
Watkins JE, Rutledge SS, Baenziger PS, and Youngquist W. 1998.
Physiologic specialization of Puccinia recondita f. sp.
tritici in Nebraska during 1995 and 1996. Plant Dis 82:679-682.