Requests for WGRC germ plasm and reprints.
E-mail requests for WGRC germ plasm, germ plasm releases,
and publication reprints can now be made to wgrc@ksu.edu.
Update: improved germ plasm lines with pest
resistance genes from Aegilops tauschii.
D.L. Wilson, B.S. Gill, and W.J. Raupp.
In previous research, Ae. tauschii has proven
to be an excellent source for producing pest resistant germ plasm
lines (see list of released germ plasm lines in Table 1). Current
data indicate Ae. tauschii will continue to be a valuable
source of resistance for these and new pests. Several research
groups are transferring genetic resistances from Ae. tauschii
into bread wheat. The coordination
of this research will amplify this effort by avoiding duplication
of effort in the evaluation of the collection, stimulating additional
research by providing information on the resistance spectrum of
each accession, and raising the awareness of the individual investigator
for potential variability in their segregating populations.
Table 1. Germ plasm releases from the Wheat Genetics Resource Center with pest resistance from
Aegilops tauschii.
____________________________________________________________________________________________
Germ plasm Resistance 1 Germ plasm Resistance 1
____________________________________________________________________________________________
KS85WGRC01 H22 KS92WGRC15 leaf rust
KS86WGRC02 leaf rust KS92WGRC16 Lr43
KS89WGRC03 Hessian fly KS92WGRC21 powdery mildew, WSBMV, WSSMV
KS89WGRC04 H23, WSBMV, greenbug KS92WGRC22 powdery mildew, WSBMV, WSSMV
KS89WGRC06 H24 KS93WGRC26 H26
KS89WGRC07 leaf rust KS95WGRC33 Septoria leaf blotch
KS90WGRC10 Lr41 KS96WGRC39 tan spot
KS91WGRC11 Lr42, WSBMV, WSSMV KS96WGRC40 wheat curl mite, Septoria nodorum
KS91WGRC12 leaf rust, adult
____________________________________________________________________________________________
1 WSBMV = wheat soilborne
mosaic virus; WSSMV = wheat spindle streak mosaic virus.
Sex, segregation, and recombination in Ae. tauschii.
J.D. Faris, B.A. Laddomada, E.V. Boiko, K.S. Gill, and B.S. Gill.
Beginning in 1989, we have been developing a genetic
linkage map of the D-genome diploid Ae. tauschii using
an F2 population of 56 plants from a cross of varieties
meyerii (TA1691) and typica (TA1704). We previously
noted that all five loci of the rudimentary 5D-linkage map from
our laboratory (Genome 32:724-732, 1989) deviated from
the expected 1:2:1 ratio. Major segregation-distortion loci were
detected on chromosome arms 1DL, 3DL, 4DS, and 7DS in addition
to 5DL. Segregation distortion was caused by the deficiency of
TA1704 homozygotes in all cases except 7DS, where individuals
for TA1691 homozygous alleles were deficient. We have created
reciprocal backcross populations of almost 200 individuals based
on male and female meiosis. We can now confirm that 5DL deviant
loci show normal segregation through female gametes, but TA1691
alleles are preferentially transmitted (at a 90 % or higher frequency)
through the male gametes. Similar analysis in underway for the
alleles associated with other segregation distortion loci.
Publications.
Badaeva ED, Friebe B, and Gill BS. 1996. Genome
differentiation in Aegilops. 1. Distribution of highly
repetitive DNA sequences on chromosomes of diploid species. Genome
39:293-306.
Badaeva ED, Friebe B, and Gill BS. 1996. Genome
differentiation in Aegilops. 2. Physical mapping of 5S
and 18S-26S ribosomal RNA gene families in diploid species.
Genome 39:1150-1158.
Brown-Guedira GL, Gill BS, Bockus WW, Cox TS,
Hatchett JH, Leath S, Peterson CJ, Thomas JB, and Zwer PK. 1996.
Evaluation of a collection of wild timopheevi wheat for resistance
to disease and arthropod pests. Plant Dis 80:928-933.
Brown-Guedira GL, Gill BS, Cox TS, and Leath
S. 1997. Transfer of disease resistance genes from Triticum
araraticum to common wheat. Plant Breed (In press).
Brown-Guedira GL, Badaeva ED, Gill BS, and Cox
TS. 1996. Chromosome substitutions of Triticum timopheevii
in common wheat and some observations of the evolution of
polyploid wheat species. Theor Appl Genet 93:1291-1298.
Cox TS, Bockus WW, Gill BS, Sears RG, Heer WF, and
Long JH. 1996. Notice of release of KS95WGRC33 hard red winter
wheat germplasm resistant to Septoria leaf blotch. Fall Cereals
Conf, 3-4
August, 1995, Manhattan, KS. p.8.
Cox TS, Gill BS, Sears RG, Harvey TL, Hatchett JH,
Hulbert SH, Brown-Guedira, GL, Faris, JA, Friebe B, Gill
KS, Knackstedt MA, Raupp WJ, Thiry D, and Van Metteren ND. 1996.
Research summary. Ann Wheat Newslet 42: 250-261.
Endo TR and Gill BS. 1996. The deletion stocks
of common wheat. J Hered 87:295-307.
Friebe B, Badaeva ED, Hammer K, and Gill BS. 1996.
Standard karyotypes of Aegilops uniaristata, Ae.
mutica, Ae. comosa ssp. comosa and
heldreichii (Poaceae). Pl Syst Evol 202:199-210.
Friebe B and Cortez F. 1996. Sister chromatid exchange
and replication banding. In: Plant Chromosomes. Laboratory
Methods (Fukui K and Nakayama S eds). CRC Press, Boca Raton,
FL. pp. 171-186.
Friebe B, Endo TR, and Gill BS. 1996. Chromosome
banding methods. In: Plant Chromosomes. Laboratory Methods
(Fukui K and Nakayama S eds). CRC Press, Boca Raton, FL. pp.
123-153.
Friebe B and Gill BS. 1996. Chromosome banding
and genome analysis in diploid and cultivated polyploid wheats.
In: Methods of Genome Analysis in Plants (Jauhar PP ed).
CRC Press, Boca Raton, FL. pp. 39-59.
Friebe B, Gill KS, Tuleen NA, and Gill BS. 1996.
Transfer of wheat streak mosaic virus resistance from Agropyron
intermedium into wheat. Crop Sci 36:857-861.
Friebe B, Tuleen NA, Badaeva ED, and Gill BS. 1996.
Cytogenetic identification of Triticum peregrinum
chromosomes added to common wheat. Genome 39:272-276.
Friebe B, Jellen EN, and Gill BS. 1996. Verification
of the identity of the Chinese Spring ditelosomic stocks Dt7DS
and Dt7DL. Wheat Inf Serv 83:31-32.
Friebe B, Jiang J, Raupp WJ, McIntosh RA, and Gill
BS. 1996. Characterization of wheat-alien translocations
conferring resistance to diseases and pests: current status.
Euphytica 91:59-87.
Gill BS. 1996. The molecular cytogenetic analysis
of economically important traits in plants. In: Kew Chromosome
Conf IV (Brandham PE and Bennett MD eds). Royal Botanic Gardens,
Kew, United Kingdom. pp. 47-53.
Gill BS, Gill KS, Friebe B, and Endo TR. 1996.
Expanding genetic maps: reevaluation of the relationship between
chiasmata and crossovers. In: Chromosomes Today Volume
12 (Henriques-Gil N, Parker JS, and Puertas MJ eds). pp.
283-300.
Gill KS and Gill BS. 1996. A PCR-based screening
assay of Ph1, the chromosome pairing regulator gene of
wheat. Crop Sci 36:719-722.
Gill KS, Gill BS, Endo TR, and Boyko EV. 1996.
Identification and high-density mapping of gene-rich
regions in chromosome group 5 of wheat. Genetics 143:1001-1012.
Gill KS, Gill BS, Endo TR, and Taylor T. 1996.
Identification and high-density mapping of gene-rich
regions in chromosome group 1 of wheat. Genetics 144:1883-1891.
Gill KS, Nasuda S, and Gill BS. 1996. Isolation,
cloning, and gel blot analysis of high molecular weight DNA.
BioTechniques 21:572-576.
Hohmann U, Badaeva K, Busch W, Friebe B, and Gill
BS. 1996. Molecular cytogenetic analysis of Agropyron
chromatin specifying resistance to barley yellow dwarf virus in
wheat. Genome 39:336-347.
Hussein T, Bowden RL, Gill BS, and Cox TS. 1996.
Performance of four new leaf rust resistance genes from Triticum
tauschii and T. monococcum. Phytopath 86:S24
(Abstract).
Jellen EN and Gill BS. 1996. C-banding variation
in the Moroccan oat species Avena agadiriana (2n = 4x =
28). Theor Appl Gene t 92:726-732.
Jellen EN, Gill BS, Rines HW, Fox SL, Wilson WA,
and McMullen MS. 1996. Translocations in current and ancestral
spring and winter oat accessions. Agron Abstr.
Jiang J, Nasuda S, Dong F, Scherrer CW, Wing RA,
Gill BS, and Ward DC. 1996. A conserved repetitive DNA element
located in the centromere of cereal chromosomes. Proc Natl Acad
Sci USA 93:14210-14213.
Jiang J, Hulbert SH, Gill BS, and Ward DC. 1996.
Interphase fluorescence in situ hybridization mapping:
a physical mapping strategy for plant species with large complex
genomes. Molec Gen Genet 252:497-502.
Kawahara T, Badaeva ED, Badaev NS, and Gill BS.
1996. Spontaneous translocations in Triticum araraticum
Jakubz. Wheat Inf Serv 83:7-14.
Zhang J, Friebe B, Raupp WJ, Harrison SA, and Gill
BS. 1996. Wheat embryogenesis and haploid embryo production
in wheat x maize hybrids. Euphytica 90:315-324.
Jiang J and Gill BS. 1996. Current status and potential
of fluorescence in situ hybridization in plant genome
mapping. In: Genome Mapping in Plants (Paterson AH ed).
R.G. Landes Co. pp.127-135.
Raupp WJ. 1996. Annual Wheat Newsletter, Vol. 42.
463 pp.
Raupp WJ, Wilson DL, Friebe B, and Gill BS. 1996.
Current status of the Wheat Genetics Resource Center gene bank:
Investigating the flow of germ plasm. Agron Abstr.
Sears RG, Gill BS, Cox TS, and Paulsen GM. 1996.
If Turkey Red had been Turkey White. Agron Abstr.
Wilson DL, Cox TS, Gill BS, Raupp WJ, Hatchett JH,
Harvey TL, and Thomas JB. 1996. Pest resistance and agronomic
evaluations of Aegilops tauschii. Agron Abstr.
U.S. GRAIN MARKETING AND PRODUCTION RESEARCH CENTER
U.S. Grain Marketing Research Laboratory, USDA, Agricultural Research
Service, Manhattan, KS 66502, USA.
O.K. Chung, G.L. Lookhart, J.L. Steele, S.R. Bean,
I.Y. Zayas, C.R. Martin, J.B. Ohm, D.B. Bechtel, L.M. Seitz, J.D.
Wilson, J.D. Hubbard, J.M. Downing, C.S. Chang, D.W. Hagstrum,
K.J. Kramer, D.B. Sauer, W.J. Jun, H.S. Park, S.H. Park, J.E.
Baker, P.W. Flinn, T.D. Morgan, W.H. McGaughey, B.W. Seabourn,
Y.S. Kim, M.D. Shogren, and D.E. Koeltzow.
New methods help to solve the gluten puzzle.
A wide range of methods for characterizing gluten
proteins were discussed at the Gluten Workshop this year. These
methods included: solubility of gluten proteins and their relationships
to quality; high-performance capillary zone electrophoresis
(CZE) for unique separations of gluten proteins and fractions,
HPLC separations to purify and characterize gluten proteins; the
use of antibodies to identify specific proteins; electrophoresis
for studying protein fractions at the individual protein and gene
levels; MALDI-TOF for accurate mass analysis of proteins
and sequences of peptides; biophysical studies using NMR, atomic-force
spectroscopy, and FT-IR
to study the structures and interactions of gluten proteins; and
the combined use of genetics with all of the above methods to
study not only diploids, but hexaploid bread wheats as well.
Because most of those methods will be discussed in detail, this
presentation will begin with an overview of the newest CZE methods
and end with a broad discussion of the other methods that will
include some crystal-ball gazing into how each of the methods
uncovers some portion of the puzzle that illustrates gluten protein
structure on a molecular level and an understanding of end-use
quality on a practical scale. (Presented at the Gluten Workshop,
Sydney, Australia)
Ultrastructure of consecutively extracted and flocculated
gliadins and glutenins.
Gliadin and glutenin are characterized by specific
ultrastructures, which depend on variety and separation conditions.
Gliadins of the Israeli spring wheat Ariel extracted with 80
% ethanol appeared as spherical bodies within an amorphous perforated
matrix. The gliadins of a commercial sample of U.S. hard red
winter wheat were deposited in bundles of bodies of concentric
membrane-like units during water dialysis and they tended
to separate when heated at 120 C.
Acetic-acid-extracted glutenins heated at 120 C
appeared as amorphous, compact agglomerated particles beside dispersed
aggregates, fibril-like patterns, and oil-like bodies.
The extracted glutenins, which were dialyzed in water, appeared
as dispersed or aggregated particles beside oil-like bodies
embedded in and/or encapsulated by coagulated protein. Differences
were found in high-performance capillary electrophoresis
patterns of both gliadins and glutenins between the Israeli spring
wheat Ariel and the good baking-quality U.S. HRWW Karl 92. The
structural differences are results of different proteins and differences
in the physicochemical properties of the proteins.
High-performance capillary electrophoresis (HPCE)
was used to analyze grain proteins from wheat cultivars with the
T1AL-1RS
or T1BL-1RS
wheat-rye
chromosomal translocations. Chromosome specific patterns were
observed among released cultivars and experimental lines. The
method was verified by analyzing protein extracts of the heterogeneous
cultivars Nekota and Rawhide and their homogeneous, homozygous
non-1RS progeny. The purified T1AL-1RS
and T1BL-1RS
progenies were derived from Nekota and Rawhide, respectively.
HPCE provides a rapid and efficient method for detection of flour
or grain derived from T1AL-1RS
and T1BL-1RS
wheats and can differentiate the two types of translocations.
Gliadins and glutenins from four wheat cultivars
were separated by a new two-dimensional technique. Protein extracts
were separated by RP-HPLC as the first dimension with each
30-second interval collected separately. Those fractions were
separated by free-zone capillary electrophoresis (FZCE) for the
second dimension. Data were combined into two dimensional (2-D)
surface contour plots similar to traditional gel electrophoresis
2-D maps. C8 and C18 columns were used in the first dimension
to separate gliadins and glutenins, respectively. Uncoated fused
silica capillaries (`27
cm x 25 m'
i.d.) were used for the second dimension FZCE separations. Differences
in the 2-D maps of both gliadin and glutenin fractions were found
between pairs of both closely related and sister lines that varied
in quality.
HPCE is a relatively new method for separating cereal
proteins. The inherent advantages of HPCE are low mass requirements,
fast separations, automation, and quantitative determinations
via UV-detection through the capillary. HPCE utilizes fused
silica capillaries with internal diameters of 20-100
m and lengths varying from 27-100
cm. Constant voltage of up to 30 KV is applied across the ends
of the capillary, providing the pump to move the ionic materials.
Components move inside the capillaries by the net value of electrophoretic
mobility and a process called electroosmotic flow, which has to
do with the electrical double layer at the capillary surface and
movement of bulk electrolyte towards the cathode. The two most
important factors of any separation technique are resolution and
reproducibility. Our early work with free zone electrophoresis
showed that low pH (2.5) phosphate buffers (0.1 M) containing
a polymeric additive (0.05 % hydroxypropylmethyl-cellulose)
provided good resolution and reproducibility. Modifications of
this buffer with the zwitter ionic detergent, lauryl-sulfobetain
and/or acetonitrile led to improved resolution over other methods.
Rinsing the capillaries with phosphoric acid yielded better reproducibility
than previous methods. Excellent separation of glutenins, gliadins,
and gliadin fractions by free zone electrophoresis has been achieved
on `27
cm x 20 m'
i.d. capillaries in less than 20 min. The relative standard deviation
of gliadins ranged from 0.1 to 0.2 %. Size based separations
by HPCE are possible with the use of polyacrylamide sieving solutions.
Werner et al. (Cereal Chem 71:397 1994) reported the use
of `Prosort'
by Applied Biosystems, a commercial sieving solution, for gluten
proteins, stating that HMW-GS could be separated, but not
identified, using this method without improvements in reproducibility
and resolution. Other electrophoretic techniques have been adapted
for HPCE including IEF and 2-D analyses.
Area quantification of proteins by high performance capillary
electrophoresis.
Wheat proteins are known as the major determinate
in bread making quality. Therefore, a wide variety of analytical
techniques have been used to separate them; the most prevalent
being PAGE and HPLC. HPCE was introduced for separating wheat
proteins by researchers at Beckman Instruments Inc in 1992. Many
research groups have used HPCE for wheat protein studies. A major
focus of several of these studies involves quantifying the area
of separated proteins in attempts to relate relative areas of
specific proteins to quality parameters. Because proteins migrate
through capillaries under the influence of an electric field in
HPCE, movement is dependent on the charge on the proteins. Thus,
proteins with different charges move at different velocities and,
therefore, spend different amounts of time in the detector path
of capillaries. This directly influences the width of peaks and
thereby the area under the peak. Therefore, raw peak areas cannot
be used in HPCE for area quantification. To correct for this,
peak areas must be divided by migration time. This corrects for
peaks with different velocities and allows for comparisons of
peak areas from proteins with different migration times. Caution
must be used in interpreting data and conclusions from studies
based on area quantification of proteins via HPCE that do not
explicitly state the use of corrected migration areas. (Abstract
of review paper)
Ultrastructure of developing hard and soft red winter wheats
after air- and freeze-drying.
Field-grown HRWW Karl and SRWW Clark were harvested
at 15, 18, 21, 23, 25, 28, and 35 days after flowering. Wheat
was dried by either air-drying in the spike at 28 C
or freeze-dried following freezing in liquid nitrogen. The
dried wheat was prepared for microscopy. Fresh samples of Karl
and Clark also were harvested on the above days and prepared immediately
for light and transmission electron microscopy. The method of
drying greatly affected cellular ultrastructure. The most pronounced
change upon air-drying of developing samples was disappearance
of individual protein bodies and conversion of the cytoplasm into
a matrix-like material similar to storage protein matrix
in mature wheat endosperm. Freeze-dried wheats maintained
near-natural ultrastructure, but exhibited various amounts of
freeze damage. Conversion of protein bodies to matrix protein
was not observed in freeze-dried samples. The results suggest
that hardness develops as a result of endosperm senescence rather
than accumulation of particular grain components. Senescence
may cause changes in the starch granule surface such that surrounding
components bind tightly in hard wheats, whereas the binding is
weaker in soft wheats. Therefore, the surface of starch granules
might be more important than components to which the starch granules
bind in determining hardness.
Determining size distributions of wheat starch encompasses
the measurement of particles that range in size from less than
one [micro]m
to over 35 [micro]m
in diameter. Quantitative image analysis is a method that yields
large amounts of data on individual starch granules. High magnifications
are required in order to measure the small starch granules. The
high magnifications used reduce the probability large granules
will be counted, however. This study was undertaken to estimate
the amount of error associated with counting the large type A
starch granules in comparison to small granules at two different
magnifications. Two analytical-grade sizes of latex spheres
(5 and 25 [micro]m)
were mixed in a 1:1 concentration as determined by use of a hemacytometer.
The spheres were then counted using an image analyzer at two
magnifications (10X and 25X objectives). Analysis indicated that
use of the 10X objective underestimated the number of 25 [micro]m
spheres by 8 %. Use of the 25X objective resulted in undercounting
the large latex spheres being by 26 %. This information will
be utilized in developing an automated image analysis protocol
for determining starch size distributions.
Field-grown hard (Pioneer 2163, Arkan, Karl,
Newton, Tam 107, and Tam 200) and soft (Caldwell and Clark) red
winter wheats were harvested at 15, 18, 21, 23, 25, 28, and 35
days after flowering. Wheat was dried by a variety of methods:
air-dried in the head at 28 C;
oven-dried in the head at 40 C;
freeze-dried following freezing and threshing in liquid nitrogen;
field-dried mature wheat; and freeze-thawed/air-dried
where samples were first frozen in liquid nitrogen, thawed at
room temperature, and then air-dried at 28 C.
The U.S. Grain Marketing Single Kernel Wheat Characterization
System was used to measure various grain parameters including
the hardness of individual grains. Air-dried and oven-dried
samples generally had similar hardness values when compared to
mature samples. Soft wheats also were softer than hard samples
when dried by these two methods. Freeze-dried grains all
had similar, very low values of hardness for samples harvested
between 15 and 28 days after flowering, but mature grains 35 days
after flowering had normal hardness values. Freeze-thawed
samples had hardness values slightly higher than either air-
or oven-dried wheats.
Changes in cereal testing and product quality evaluation
methodologies at the turn of the century.
Many issues directly affecting cereal science and
technology and also processing of cereal products have been arising
on a global scale. These issues include food safety, nutritional
labeling, integrated pest management, environmental protection,
and occupational safety and health. A rapid advance in computer
technology will be one of the most important vehicles to adapt
the necessary changes in testing methodologies at the turn of
the century. Main key words in changing methods are speed, accuracy,
safety, environmental friendliness, and objectivity. Some examples
of changing methodologies include the Leco N2 Analyzer
for protein contents; capillary zone electrophoresis (described
above) for protein characterization; supercritical fluid extraction
for fats, nutrients, and pesticide residues; solid phase extraction
for lipid fractionation on a small scale; digitized imaging for
bread loaf sizes and crumb grains, and grains and milled products;
NIR for biochemical estimation and quality prediction; and machine-sensing
for grain odors.
Environmental concerns, the disposal cost of hazardous
waste, and the time required for extraction encouraged us to look
for a method to extract lipids from wheat flour that would be
faster, less costly, and more environmentally responsible. Free
lipids (FL) were extracted from eight wheat samples (1 durum semolina
and 7 flours) using a Soxhlet, a Supercritical Fluid Extraction
(SFE) system with CO2, and an SFE system with CO2
plus 12.3 mole % ethanol as modifier at 7,500 psi pressure at
80 C chamber
temperature with a flow rate of 3 mL/min for 20 min. FL extractability
by SFE with CO2 averaged only about 78 % of that by
Soxhlet extraction, whereas that by SFE with a modifier averaged
110 %. The extracted FL were fractionated by Solid Phase Extraction
(SPE) system and open column silica chromatography (OCSC) with
a chloroform-acetone
(4:1) mixture, acetone, and methanol as eluting solvents for nonpolar
lipids (NL), glycolipids (GL), and phospholipids (PL). The lipid
composition expressed as % FL was similar for both SPE and OCSC
fractionation methods irrespective of extraction methods. For
the FL extracted by SFE with a modifier, NL ranged from 62.3 to
78.4 % by SPE and 63.2 to 81.5 % by OCSC; GL from 11.2 to 32.5
% by SPE and 12.0 to 30.1 % by OCSC and PL from 5.2 to 11.0 %
by SPE and 5.4 to 7.6 % by OCSC. Lipid extraction was replicated
4 times and each fractionation by SPE and OCSC was duplicated,
giving very high reproducibility. We used a 1-gram cartridge
(bonded phase silica) and a total 56 ml of solvents for SPE and
5-gram silica and 165 ml of solvents for OCSC methods. Fractionation
could be done for 12 samples/hr by SPE and six samples/5 hr by
OCSC.
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