USDA-ARS, Small Grain Insect Control Laboratory
Crop Production and Pest Control Research Unit,Department of Entomology,
West Lafayette, IN 47907, USA.
R.H. Shukle, V.W. Russell, and L. Zantoko.
Molecular basis of the Hessian fly/wheat interaction.
The objectives of research on the Hessian fly included
1) genetic mapping of genes controlling virulence, 2) molecular
characterizing regions of the genome containing virulence genes,
3) determining the mode of action of virulence genes, and 4) identifying
alien genes for resistance for insertion (transformation) into
wheat to increase resistance to the Hessian fly.
Genetic analyses indicate that virulence in the Hessian
fly operates on a gene-for-gene basis with the resistance
gene H13 in wheat, and the allele controlling virulence
to H13 (vrH13) is linked to the allele controlling
white-eye (w). The distance between w and
vrH13 was estimated at 24.3 +/-
0.02 map units. RAPD markers linked to the white allele have
been detected with OPERON primers OPE-09 and OPE-17.
The polymorphic sequence OPE-091100 was cloned
in the vector pT7Blue and has been sequenced. OPE-091100
was physically positioned through in situ hybridization
near the end of the long arm of polytene chromosome 3 (sex chromosome
X1). The physical location of marker OPE-091100
suggests the white-eye allele, and perhaps the allele controlling
virulence to H13, also are located near the end of the
long arm of sex chromosome X1.
A mariner transposable element has been identified
from the Hessian fly. An intact element was recovered and codon
usage for the mariner transposase compared with that for
a conserved protein (i.e., an actin) from Hessian fly. Insertion
sites for mariner elements within the genome of the Hessian
fly and biological activity of the intact element are being investigated.
The Bowman-Birk proteinase inhibitor (BBPI)
has been reported to be a putative resistance factor for protection
of wheat from Hessian fly (Shukle et al. 1985, Insect Biochem
15:93). In collaborative work between this laboratory
and J. Troy Weeks (USDA-ARS,
University of Nebraska-Lincoln),
the BBPI gene is being inserted into wheat for the purpose of
increasing resistance to the Hessian fly and other insect pest.
Publications.
Russell VW and Shukle RH. 1997. Molecular and cytological
analysis of a mariner transposon from Hessian fly. J Hered
87:in press.
Zantoko L and Shukle RH. 1997. Genetics of virulence
in the Hessian fly to resistance gene H13 in wheat. J
Hered 87:in press.
KANSAS AGRICULTURAL STATISTICS
U.S. Department of Agriculture, 632 SW Van Buren, Rm. 200. P.O.
Box 3534, Topeka, KS 66601-3534, USA.
T.J. Byram.
Karl number one again.
Karl and improved Karl remained the leading variety
of wheat seeded in Kansas for the 1997 crop, according to Kansas
Agricultural Statistics. Accounting for 22.1 % of the state's
wheat, Karl increased slightly from a year ago. Karl was, by
far, the most popular variety seeded in the eastern third of the
state, and the second most popular in the central third. TAM
107 moved into second position with 17.0 % of the acreage. TAM
107 was the dominant variety planted in the western third of the
state. Pioneer 2163, accounting for 15.4 % of the acreage statewide,
dropped to the third leading variety seeded in Kansas. The variety
was seeded to the most acreage in the central third of the state.
Ike ranked fourth overall again this year with 10.5 % of the
State's
wheat. Ike was the second leading variety in the western third
and ranked in the top five in the central third of the state.
Jagger, with 6.4 % of the state acreage, moved into the top 10
as the fifth most popular variety. Jagger ranked in the top five
in the eastern and central thirds of the state and the southwest
district. Moving up to sixth, AGSECO 7850 was seeded on 4.0 %
of the wheat acreage. Larned, with 3.6 % of the wheat acreage,
dropped to seventh in the state. AgriPro's
Tomahawk, with 3.1 % of the acreage, was the eighth leading variety.
Rounding out the top 10 were AgriPro Pecos with 1.6 % and AgriPro
Ogalala with 1.3 % of the seeded acres.
Publications.
Monthly Crop. Wheat cultivars,
percent of acreage devoted to each cultivar. Wheat quality, test
weight, moisture, and protein content of the current harvest.
$10.00
Crop-Weather. Issued
each Monday, 1 March through 30 November, and monthly December
through February. Provides crop and weather information for previous
week. $12.00.
County Estimates. County
data on wheat acreage seeded and harvested, yield, and production
on summer fallow, irrigated, and continuous cropped land. December.
Wheat Quality. County
data on protein, test weight, moisture, grade, and dockage. Included
milling and baking tests, by cultivar, from a probability sample
of Kansas wheat. September.
Each of the above reports is available on the Internet
at the following address: <http://www.nass.usda.gov/ks/>.
INSERT FIGURES 1 AND 2. ORIGINALS ONLY.
INSERT TABLE 1. ORIGINAL ONLY.
INSERT TABLE 2. ORIGINAL ONLY.
Departments of Agronomy and Biochemistry
Throckmorton and Willard Halls, Manhattan, KS 66506-5501, USA.
Expression of a rice chitinase gene in transgenic wheat
plants.
Xu Gu1, S. Muthukrishnan2, and G. H. Liang1.
1Department of Agronomy
and 2Department of Biochemistry.
A rice chitinase gene and the tobacco hornworm (Manduca
sexta) chitinase cDNA under the control of the CaMV 35S promoter
have been introduced into wheat plants through microprojectile
bombardment. A total of 2,300 immature zygotic embryos from Pavon
76, Bobwhite, and Jagger were bombarded with a plasmid DNA containing
the selectable marker bar gene conferring bialaphos resistance
and a rice chitinase gene or a M. sexta-chitinase gene.
Fifty-one plants were obtained after selection initially
in a medium with 1 or 2 mg/L bialaphos followed by a rooting medium
with 1 mg/L bialaphos.
Western blot analysis of extracts of 50 bombarded
wheat calli indicated that four had the expected 35 kDa rice chitinase
band. From 111 R0 plants of Pavon 76 regenerated from
calli, the presence of a chitinase with an apparent molecular
weight of 35 kDa was detected in five plants. Out of eight R0
plants of Bobwhite, three plants contained the expected 35 kDa
band. Among plants obtained after bombardment with the M.
sexta-chitinase gene, only one out of 20 R0 plants
had an immunoreactive polypeptide with a molecular weight about
48 kDa. A higher percentage of the putative transgenic plants
tested positive in the phosphinothricin acetyl transferase assay.
Expression of rice or M. sexta-chitinase gene
also was studied in R1 plants of Pavon 76 and Bobwhite.
These results suggest segregation of the rice or insect chitinase
gene in the R1 generation. The integration of a rice
chitinase gene into the wheat genome was confirmed by Southern
blot analysis. When genomic DNA from three independent R0
transgenic plants of Pavon 76 (#6, #7, and #8), which gave a positive
reaction in the western blot analysis, was digested with HindIII
and probed with a rice CHI 11 chitinase fragment, the 1.53 kb
band diagnostic of the transgene was detected in all three R0
plants. When three R1 progeny from the R0
plant (#15) were probed with the insect chitinase fragment, the
2.23 kb band containing the M. sexta-chitinase gene was
found in the genomic DNA of two R1 plants (#15-1
and 15-2), which also gave a positive reaction in western
blot analysis.
News.
Dr. Xu Gu received his Ph.D. in 1996 from KSU. He
is now a postdoctoral fellow at the Plant Molecular Biology Division,
CSIRO, Canberra, Australia. He is working on wheat transformation
using Agrobacterium tumefaciens.
Dr. Jianwen Liu, a postdoctoral fellow from Beijing
Normal University, has joined the Plant Genetics Laboratory, Department
of Agronomy, KSU, February, 1997. He will be working on in situ
hybridization, wide crosses, and addition lines of Eremopyrum
and wheat for biotic (powdery mildew), or abiotic resistance (drought
and salt), and early maturity.
Ms. Qing-li Mi has joined the Plant Genetics Laboratory, KSU, in May, 1996, Departments of Agronomy, Biochemistry, and Entomology to work on wheat transformation using Agrobacterium tumefaciens and genes for chitinases and TLP (thaumatin-like-protein, an antifungal protein).
Department of Agronomy, Kansas State University, Throckmorton
Hall, Manhattan, KS 66502, USA.
M.B. Kirkham.
Increased growth of split-root wheat.
An explanation is given (Kirkham 1995) for results
of previous experiments by former student Paul I. Erickson and
me, in which we split the roots of KanKing, a drought-resistant
winter wheat and Ponca, a drought-sensitive winter wheat,
between soil and soil; between soil and nutrient solution; and
between nutrient solution and nutrient solution. The nutrient
solution was full strength Hoagland's. The split-root system
consisted of two 1,127 cm3 (23 x 7 x 7 cm) milk cartons,
three plants per pair of cartons. The nutrient solution was aerated.
The plants were 37 days old when the roots were split.
For 69 days after splitting we measured height and, at the end
of the experiment, we determined shoot weight, root weight, and
root length. Half way through the experiment, 40 d after roots
were split, water was withheld from one side of the roots split
between soil:soil and from the soil side of the roots split between
soil:nutrient solution. The time that water was withheld was
called the beginning of the `water
stress'
period. After water stress was imposed, the level of the nutrient
solution was maintained at a constant level by adding nutrient
solution back to the container, when roots were split between
nutrient solution:nutrient solution or between soil:nutrient solution.
The soil and solution containers were kept covered with black
plastic to minimize evaporation.
Both the drought-resistant (KanKing) and drought-sensitive
(Ponca) wheat cultivars had a faster shoot growth rate when water
was withheld from the soil side of roots split between soil:nutrient
solution than before water stress. For KanKing, the increase
was 3.2 times faster (0.23 cm/d before water was withheld versus
0.74 cm/d after water was withheld), and for Ponca, the increase
was 4.4 times faster (0.08 cm/d versus 0.35 cm/d). KanKing with
roots split between soil:nutrient solution had the highest shoot
weight (Table 1). Similarly, shoot weight was greatest for Ponca
plants with roots split between soil:nutrient solution.
KanKing and Ponca plants with roots split between
soil:soil also increased in growth rate after water was withheld
from one side of the soil. KanKing increased in growth rate from
0.11 cm/d to 0.54 cm/d, and Ponca increased from 0.11 cm/d to
0.50 cm/d. Height of plants with roots split between nutrient
solution:nutrient solution was generally constant during the experimental
period.
For both KanKing and Ponca at harvest, the soil side had more roots than the solution
side (3,071 cm versus 2,826 cm for KanKing; 1,284
cm versus 912 cm for Ponca) (Table 1).
The results are explained by using a model for movement
of water in plants with split-roots (Kirkham 1983). The
water potential at the crown determines the direction of flow
of water in the plant. When roots were split between soil:nutrient
solution, there was a potential gradient, and part of the solution
from the solution side moved to the root in the soil and part
moved to the shoot. When water stress was imposed (no water added
to the soil side), the gradient became stronger, and more water
moved from the solution side to the soil side. At the same time,
growth increased. Paradoxically, a water stress resulted in increased
growth. This was probably because more roots were produced on
the soil side of roots split between soil:nutrient solution (compared
to roots grown only in solution or only in soil), and the increased
root growth permitted increased shoot growth. If nutrients are
in the solution, then a split root, acting as a wick, draws nutrient-rich
solution from the solution side to the soil side of the root system.
Nutrients feed the roots and shoots. As long as the roots can
wick over the nutrient solution, the plants thrive.
Table 1. Shoot weight, root weight, and root length at harvest of a drought-resistant cultivar (KanKing) and a
drought-sensitive cultivar (Ponca) of winter wheat with roots split between soil:soil, soil:nutrient solution, and
nutrient solution:nutrient solution. Plants were
106 days old at harvest. Values are mean +/-
standard deviation.
__________________________________________________________________________________________
Soil:Soil Soil:Solution Solution:Solution
no water watered no water
Cultivar after day 77 side after day 77
__________________________________________________________________________________________
Shoot weight (g)
KanKing 4.27 +/- 0.86 11.33 +/- 1.47 7.23 +/- 1.14
Ponca 3.46 +/- 0.56 4.50 +/- 2.79 2.26 +/- 0.47
Root weight (g)
KanKing 0.83 +/- 0.25 0.49 +/- 0.13 5.03 +/- 0.82 4.26 +/- 1.44 1.36 +/- 0.11 1.79 +/- 0.34
Ponca 0.36 +/- 0.12 0.42 +/- 0.14 1.08 +/- 0.69 0.55 +/- 0.34 0.24 +/- 0.07 0.03 +/- 0.10
Root length (cm)
KanKing 1,247 +/- 168 928 +/- 158 3,071 +/- 366 2,826 +/- 526 1,770 +/- 78 1,966 +/- 110
Ponca 679 +/- 172 756 +/- 582 1,284 +/- 582 912 +/- 480 482 +/- 146 572 +/- 188
_________________________________________________________________________________________
The results might have application under field conditions.
A split-root system, with part of the roots in saturated
soil and part in unsaturated soil might be realized at times under
furrow (row) irrigation or in furrow-dike irrigation, where
water is applied directly from a center pivot sprinkler system
to a furrow with small dikes placed across the furrow every 30
cm (foot) or so. The furrow dikes hold the water in place until
it can soak into the soil. The soil is saturated in the pools
between the dikes in the rows, but unsaturated between the rows.
If a plant could be planted so that part of its root system would
grow in the pond of a furrow and part in the adjacent unsaturated
soil, then the part of the root in the pond would be transferring
water to the part of the root in unsaturated soil. The root system
might be larger in the unsaturated part of the soil possibly resulting
in a larger plant, along with, perhaps, increased yields. This
should be tested in the field.
References.
Kirkham MB. 1983. Physical model of water in a
split-root system. Plant Soil 75:153-168.
Kirkham MB. 1995. The impact of W.R. Gardner on
soil-plant water relations: split roots and hydraulic resistance.
Agron Abstr 87:191.
News.
Yan Song has joined the Evapotranspiration Laboratory working on her M.S. degree. She is using a dual-probe heat-pulse (DPHP) technique, being developed at Kansas State University by Jay M. Ham and Gerard J. Kluitenberg, which allows rapid measurement of soil volumetric heat capacity that can be converted directly to soil volumetric water content. Our purpose is to determine if this method can be used to monitor changes in water content in soil with roots. The instrument is unique, because it allows measurement of water in a miniature volume of soil. She has done experiments with grass roots (tall fescue; Festuca arundinacea Schreb cv. Kentucky 31), and she is finding excellent agreement between measurements made with the DPHP technique and gravimetric measurements.
Publications.
Manunta P and Kirkham MB. 1996. Respiration and
growth of sorghum and sunflower under predicted increased night
temperatures. J Agron Crop Sci 176:267-274.
Zhang JX and Kirkham MB. 1996. Antioxidant responses
to drought in sunflower and sorghum seedlings. New Phytol 132:361-373.
Zhang JX and Kirkham MB. 1996. Lipid peroxidation
in sorghum and sunflower seedlings as affected by ascorbic acid,
benzoic acid, and propyl gallate. J Plant Physiol 149:489-493.
Zhang JX and Kirkham MB. 1996. Water relations
and ethylene production of water-stressed, split-root
sorghum and sunflower plants. In: Proc Fourth Congr
Eur Soc Agron (van Ittersum MK, Venner GEGT, van de Geijn SC,
and Jetten TH eds). Research Institute for Agrobiology and Soil
Fertility, Wageningen, The Netherlands. pp. 126-127.
The Wheat Genetics Resource Center
Departments of Plant Pathology and Agronomy and the USDA-ARS,
Throckmorton Hall, Manhattan, KS 66506-5502, USA.
New germ plasm releases from the Wheat Genetics Resource
Center.
T.S. Cox, B.S. Gill, and G.L. Brown-Guedira.
Seven new germ plasm releases were announced at the
Fall Cereals Conference, 1-2
August, 1996, in Manhattan, KS. These lines have resistance to
leaf rust, powdery mildew, tan spot, S. nodorum, and the
wheat curl mite infestation. A short description follows. Small
samples of seed of any of these lines may be requested from the
WGRC by mail or via E-mail at wgrc@ksu.edu.
KS96WGRC34, leaf rust-resistant hard red winter wheat germ plasm. Pedigree: TAM 107/TA749 (T. monococcum ssp. aegilopoides//Wrangler.
KS96WGRC35, leaf rust-resistant hard red winter wheat germ plasm. Pedigree: Wrangler*3/TA28 (T. timopheevii ssp. armeniacum).
KS96WGRC36, leaf rust-resistant hard red winter wheat germ plasm. Pedigree: Wrangler*3/TA145 (T. timopheevii ssp. armeniacum).
KS96WGRC37, powdery mildew-resistant hard red winter wheat germ plasm. Pedigree: Arlin*3/TA895 (T. timopheevii ssp. armeniacum).
KS96WGRC38, tan spot-resistant hard red winter wheat germ plasm. Pedigree: KS90WGRC10*3/TA895 (T. timopheevii ssp. armeniacum).
KS96WGRC39, tan spot-resistant hard red winter wheat germ plasm. Pedigree: TAM 107*3/TA2460 (Ae. tauschii).
KS96WGRC40, S. nodorum
and wheat curl mite infestation-resistant hard red winter wheat
germ plasm. Pedigree: KS95WGRC33 reselection.
New URL for the WGRC homepage on the WWW.
The address for the Wheat Genetics Resource Center
homepage on the World Wide Web has been changed to
<http://www.ksu.edu/wgrc/>.
We continue to update our site. Now included are listings of
all publications from WGRC scientists from 1980 to present. We
also are continuing to add information on the genetics stocks
and species collections. A recent addition is the `Electronic
Lab Manual',
which currently contains protocols for chromosome banding and
in situ hybridization.
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