A Database for Triticeae and Avena
UNIVERSITY OF MISSOURI
Department of Agronomy and the USDA-ARS, Curtis Hall, Columbia,
MO 65211, USA.
A.L. McKendry, J.P. Gustafson, L.E. Sweets, K. Ross, D.N. Tague,
R.L. Wright, K.S. Salzman, S. Liu, E. Butler, T. Chikmawati, X.
Ma, A. Mahmoud, Miftahudin, and M. Rodriguez.
Kara Salzman joined the wheat breeding program as a research
specialist working to identify new sources of resistance to FHB
in winter wheat.
Crop statistics. The Missouri wheat crop was harvested
from 920,000 acres, a 26 % decrease over acres harvested in 1998.
Statewide yields are projected to average 52 bu/acre, up 6 bu/acre
from the 1998 yield. If realized, this would be the second highest
yield on record. Despite above-average yields, total Missouri
production is projected to be lower by 9.66 million bushels because
of the reduction in overall acres planted in the state. District
yields are projected to range from 43 bu/acre in northwest and
westcentral Missouri to 56 bu/acre in the southeast.
Winter wheat performance tests. The statewide yield
of SRWW tested in 1999 was 56.5 bu/acre, up 4 bu/acre from the
1998 test average of 52.5 bu/acre. However, statewide yields were
14.5 bu/acre less than the record high yield (71.0 bu/acre) recorded
in 1997. Average yields across the seven test locations ranged
from 38.1 bu/acre at Lamar to 66.4 bu/acre at Trenton. Average
regional yields ranged from 44.2 bu/acre in the southwestern region
to 53.9 bu/acre in the southeastern region and 65.4 bu/acre in
the northern region of the state.
Pioneer variety 2568 again was the highest yielding SRWW tested,
averaging 65.0 bu/acre across the state. Six proprietary varieties,
including Pioneer variety 25R26 (64.6 bu/acre), NK Coker 9663
(63.1 bu/acre), Lewis 400 (62.2 bu/acre), USG 3209 (62.2 bu/acre),
AgriPro Patton (61.5 bu/acre), and Terra Exp 216 (61.3 bu/acre),
did not differ significantly in yield from Pioneer variety 2568.
Roane (61.2 bu/acre), released by the Virginia Agricultural Experiment
Station, was the only released public variety that did not differ
significantly from Pioneer variety 2568. An experimental line
from Georgia, GA 89482E7 (61.6 bu/acre), rounded out the top-yielding
The eight hard wheat varieties tested (including Ernie as a
SRWW check) averaged 46.6 bu/acre statewide. Ernie was the top-yielding
variety in the test, averaging 54.3 bu/acre across the three locations.
Released public varieties not significantly different from Ernie
included Wesley (50.6 bu/acre), Karl 92 (49.6 bu/acre), and 2137
(43.9 bu/acre). The proprietary variety Terra HR 217 (46.7 bu/acre),
and the Kansas experimental line KS89180B2-1-1 (51.9 bu/acre)
also were in the top-yielding group.
Regional test weights varied significantly in 1999 because
of differential environmental conditions and diseases at test
locations. Statewide, the average test weight was 56.9 lb/bu,
not significantly different from the statewide average (57.0 lb/bu)
recorded for 1998. Location averages ranged from a low of 55.2
lb/bu at Columbia, where disease pressure from scab, bacterial
streak, and Septoria leaf blotch along with rainfall during harvest
lowered test weights, to a high of 58.6 lb/bu at Portageville.
Among SRWW varieties tested, NK Coker 9474 had the heaviest test
weight at 59.3 lb/bu. Two public varieties, Roane (59.1 lb/bu)
and Kaskaskia (59.0 lb/bu), and two proprietary varieties, MFA
Enterprise (58.9 lb/bu) and NK Coker 9704 (58.5 lb/bu), did not
differ significantly from NK Coker 9474. The latter has been the
variety with the heaviest test weight in 3 of the past 4 years.
Across the three locations of the hard wheat test, Karl 92
had the heaviest test weight at 56.7 lb/bu. Not significantly
different from Karl 92 were 2137 (55.1 lb/bu), Wesley (54.7 lb/bu),
Terra HR 217 (54.4 lb/bu), and the soft wheat check Ernie (54.6
lb/bu). The Nebraska experimental line NE 93496 (55.8 lb/bu) also
was in the top test-weight group, ranking second behind Karl 92.
Complete results of the 1999 Missouri Winter Wheat Performance
Tests are available on the World Wide Web under Crop Performance
Testing at: http://www.agebb.missouri.edu
J.P. Gustafson, K. Ross, E. Butler, T. Chikmawati, X. Ma, A.
Mahmoud, Miftahudin, and M. Rodriguez.
Genes and RFLP markers isolated from wheat, barley, oats, and
rye genomic and cDNA libraries of are being mapped physically
onto mitotic wheat ditelocentric chromosome preparations using
an in situ hybridization technique. The ends and translocation
break points located on the genetic linkage maps from homoeologous
groups 1, 3, 4, 5, 6, and 7 of hexaploid wheat have been completed.
In addition, the ends of several linkage groups in barley and
all of the 1993 linkage groups in rice have been mapped physically
to sites on chromosomes. The data from all three species suggest
that all genomes so far analyzed still have regions that do not
contain any polymorphic markers. The data also suggests that significant
differences do exist in recombination frequencies within a genome
or even within individual chromosomes.
Genome-specific DNA sequences and minisatellites from hexaploid
wheat are continuing to be characterized. The rice DNA-fingerprinting
sequences have been mapped to locations onto the existing Japanese
Rice Genome Project RIL mapping population. At the present time,
over 50 % of segregating bands can be placed on linkage maps.
Matrix attachment regions (MARs) have been isolated and characterized
from hexaploid wheat. AFLP markers are being mapped to the regions
of the wheat and rye genomes where the genes for tolerance to
aluminum are located.
A.L. McKendry, L.E. Sweets, D. N. Tague, R. L. Wright, K.S.
Salzman, and S. Liu.
Germ plasm evaluation. The University of Missouri has
been identified as the U.S. site for identifying new sources of
resistance to FHB in winter wheat. This research is a component
of the aggressive worldwide search for resistance to scab initiated
in 1998 with support from the National Wheat and Barley Scab Initiative.
Currently, winter wheat germ plasm from the National Small Grains
Collection at Aberdeen is being evaluated for resistance to initial
infection, spread, and kernel quality under scab inoculations
in both the greenhouse and field. Accessions from geographical
areas where resistance has been identified or where environmental
conditions are conducive to scab development have been targeted
in the initial screens and include accessions from China Table
1) and Korea, Japan, Brazil, Italy, and eastern Europe (Table
Disease resistance screening. In 1999, 937 accessions
representing winter wheat landraces, breeding lines, cultivars,
and cultivated genotypes from China, Korea, Japan, Brazil, and
Italy were screened under greenhouse conditions. At first anthesis,
plants were inoculated with 10 µl of a macroconidial suspension
of F. graminearum concentrated to 50,000 macroconidia/ml.
Inoculum was placed in a single central floret using an Oxford
8100® repeat dispensing syringe. For all inoculations, a single
isolate was used that had been determined previously to be the
most aggressive Missouri isolate on our most resistant cultivar,
Ernie. Previous research also had determined that this Missouri
isolate was more aggressive in causing disease than similar isolates
acquired from Indiana, Michigan, Ohio, and Virginia. Plants were
incubated in a mist chamber (100 % relative humidity) for 72 h
postinoculation to promote disease development and then returned
to the glasshouse bench. Ratings for type II resistance (disease
spread in the spike) were made at 14 and 21 days after inoculation.
At maturity, heads were harvested and kernels were counted and
evaluated for the degree of shriveling and the presence of tombstone
kernels. Seeds were counted and each was given a value on a 5-point
scale as follows: 1 (sound), 2 (slightly shriveled), 3 (moderately
shriveled), 4 (very shriveled), and 5 (tombstone). Lines meeting
the following criteria for resistance were progeny tested to verify
Definition of resistance. For the purposes of greenhouse
screening, type II resistance was compared to the resistant checks
Sumai 3, Ning 7840, and Ernie. The susceptible check was MO 94-317.
Lines are retained for verification that met the following criteria:
Lines were eliminated, regardless of spread, if inoculated
heads had low kernel numbers and/or a high kernel-quality score.
Distribution. Seed of each of these accessions currently
is being increased from progeny of resistant-plant selections.
Limited quantities of seed will be available in July, 2000, from
Dr. Anne L. McKendry to collaborating scientists in the National
Wheat and Barley Fusarium Head Blight Initiative. Once seed stocks
are increased sufficiently, purified sources of resistance will
be available worldwide through the National Small Grains Collection
in Aberdeen (autumn 2001).
Genetics of resistance to Fusarium head blight. Studies
investigating the inheritance of scab resistance in Ernie are
currently underway utilizing the Missouri breeding line MO 94-317,
a widely adapted and highly inbred (F12) line, as the susceptible
parent. MO 94-317 has high yield and excellent milling and baking
quality but is highly susceptible to scab with an FHBI of 0.9
and has poor kernel quality under disease pressure.
A set of populations (F1, reciprocal F1, F2, BC1, and BC2)
from the cross 'Ernie/MO 94-317' currently is under development
for conventional genetic analysis of the scab resistance in Ernie.
Population development will be completed in 1999-2000, and genetic
analyses will be conducted in the autumn of 2000.
Monosomic plants from each of the 21 Chinese Spring monosomics
developed at the University of Missouri by Dr. E.R. Sears have
been crossed with Ernie in an effort to identify critical chromosomes
influencing scab resistance in Ernie. In addition, the results
of this study will help focus molecular work aimed at identifying
markers associated with genes for scab resistance in this cultivar.
A set of F3-derived F9 RILs are being developed from the cross
'Ernie/MO 94317', which will be used to map resistance genes in
Ernie. Results from screening F6 RILs suggest that resistance
in Ernie is heritable and relatively simply inherited. Of 1,330
lines screened in the spring of 1999, 308 plants were classified
as resistant (FHBI < 0.2), 192 as moderately resistant (0.3
< FHBI < 0.5), 295 as susceptible (0.6 < FHBI < 0.8),
and 535 as very susceptible ( FHBI > 0.81). Lines are currently
in the F8. Molecular mapping is expected to begin in the autumn/winter