MISSOURI
UNIVERSITY OF MISSOURIDepartment of Agronomy and the USDAARS, Curtis Hall, Columbia, MO 65211, USA.
http://www.ext.missouri.edu/agebb/cropperf/wheat
J.P. Gustafson, A.L. McKendry, L. Sweets, K. Ross, D.N. Tague,
R. Wright, B. Rauh, T. Chikmawati,
M. Christophers, B. Kim, X. Ma, S. Madsen, A. Mahmoud, Miftahuddin,
and M. Rodriguez.
1998 MissourI winter wheat crop.
Crop statistics. Missouri's wheat crop was harvested from
1.23 million acres, an 18 % increase over acres harvested in 1997.
Despite an increase in the acreage harvested, total Missouri production
was lower by 620,000 bushels because of above-average rainfall,
a shorter growing season, and more disease pressure in some regions
of the state than occurred in the 1997 crop year. Statewide yields
averaged 46 bu/acre, down 9 bu/acre from the record high level
of 1997. District yields ranged from 40 bu/acre in south-central
Missouri to 51 bu/acre in the north-east.
1998 Missouri Winter Wheat Performance Tests. Field conditions
during the autumn of 1997 were conducive to excellent stand development
at all locations where the performance tests were grown. A relatively
mild winter resulted in survival exceeding 90 % in the northern
and southwestern regions. Freezing temperatures at stem extension
significantly reduced the number of live tillers in the southeastern
region (bootheel). Winter survival averaged 67 % and 85 % for
the Charleston and Portageville locations, respectively.
Excessive rainfall throughout the growing season, coupled with
periods of heat during early grainfill characterized the growing
season for much of the state. Leaf rust was evident during late
grainfill in the southeast and may have contributed to reduced
yields and test weights in this region. In the southwestern region,
there was very little disease pressure. However, excessive rainfall
after physiological maturity resulted in sprouting in some entries
of the soft wheat test and all but one entry of the hard wheat
test. At Columbia, Septoria leaf blotch pressure was significant
. At Novelty the crop had very high yield potential. However,
rainfall throughout the heading period resulted in high levels
of scab in susceptible cultivars. Both yields and test weights
were significantly reduced by this disease pressure.
The statewide yield of SRWWs tested in 1998 was 52.5 bu/acre,
down 18.6 bu/acre from the record high yield (71.1 bu/acre) recorded
in 1997. Average yields across the seven test locations ranged
from 37.2 bu/acre at Portageville to 61.9 bu/acre at Mt. Vernon.
Average regional yields were 41.6 bu/acre in the southeast,53.6
bu/acre in the north, and 61.7 bu/acre in the southwest.
Pioneer variety 2568 was the highest yielding SRWW tested, averaging
61.2 bu/acre across the state. Five other private varieties including
Pioneer variety 25R26, Pioneer variety 2540, Merschman Julie IV,
Pioneer variety 25R57, and Terra Exp 216 did not differ significantly
in yield from Pioneer variety 2568. Pioneer variety 2540 was the
top-yielding variety in the previous 2 years. For the second year
in a row, the highest yielding public variety was Jackson, released
by the Virginia Agricultural Experiment Station in 1993.
The five hard wheats tested averaged 55.9 bu/acre statewide. There
were no significant differences in yield among varieties. At Columbia,
Terra Exp 217 (56.2 bu/acre) and Jagger (53.3 bu/acre) were the
top-yielding varieties. At Trenton, 2137 (75.5 bu/acre), MFA H2020
(71.6 bu/acre), and Ernie, the soft wheat check cultivar (68.7
bu/acre) were in the top yield group, whereas at Mt. Vernon, Ernie
(66.0 bu/acre) and Jagger (55.9 bu/acre) were the highest yielding
varieties.
Regional test weights varied significantly in 1998 because of
differential environmental conditions at test locations. The average
statewide test weight was 57.0 lbs/bu, down 1.8 lbs/bu from the
state-wide average (58.8 lb/bu) recorded for 1997. Location averages
ranged from a low of 54.4 lb/bu at Novelty due to heavy scab pressure
to a high of 59.7 lb/bu at Columbia. Test weights in general were
lower at most locations than those recorded in1997 due to excessive
rainfall at most locations prior to harvest and high temperatures
that resulted in a shorter grainfill period. Among SRWWs tested,
Roane, released in 1998 by the Virginia Agricultural Experiment
Station, had the heaviest test weight at 60.1 lbs/bu. Four private
varieties including: LG X433, MFA Enterprise, NK Coker 9474, and
Willcross 798 did not differ significantly from Roane. NK Coker
9474 had been the variety with the heaviest test weight in the
previous 2 years. Across the three locations of the hard wheat
test, Karl 92 had the heaviest test weight at 60.3 lbs/bu. Not
significantly different from Karl 92 were 2137 and MFA H2020.
Complete data are available on the world wide web at: http://www.ext.missouri.edu/agebb/cropperf/wheat.
Wheat genetics research.
Genes, RFLP, SSR, and AFLP markers isolated from wheat
and rye are being mapped onto the ITMI rye mapping population
and a second rye RIL mapping population. The IMTI rye population
currently contains 185 markers on seven linkage groups. The ends
of the genetic linkage maps from homoeologous groups 1, 3, 4,
5, 6, and 7 of hexaploid wheat are have been physically mapped.
Physically mapping of the ends of all the 1993 linkage groups
in rice was completed. The data suggested that regions are still
present in the wheat, barley, and rice genomes that do not contain
any polymorphic markers, and that significant differences do exist
in recombination frequencies within a genome and even within individual
chromosomes. Currently, we have no explanation as to what exists
in the regions or gaps where there are currently no polymorphic
markers or apparent recombination.
Existing rice DNA fingerprinting sequence loci are being mapped
onto the existing Japanese RIL population linkage map. At present,
over 50 % of all segregating minisatellite loci have been placed
on the rice linkage map and are scattered throughout all linkage
groups. No clustering of minisatellite loci at the telomeres as
has been observed in humans is apparent.
Wheat breeding research.
Septoria tritici blotch resistance. Genetic studies
of Septoria resistance identified in the Ae. tauschii
accessions TA2470 and TA2479, acquired from the repository
of lines held at the WGRC at Kansas State University, was completed.
Resistance in TA 2470 was conditioned by a single dominant gene.
Resistance in TA 2479 was quantitatively inherited and adequately
explained by an additive gene model. Estimation of genetic effects
suggested the presence of four genes conferring resistance.
Fusarium head blight resistance. The identification of
new sources of resistance to scab was intensified with funding
from the National Fusarium Head Blight Initiative. Missouri has
been identified as the Germplasm Introduction and Evaluation Center
for resistance to scab in winter wheat. As such, an aggressive
search for resistance in winter wheat germ plasm was initiated
in the autumn of 1998. Currently, 1,000 accessions from China,
Japan, Korea, Brazil, and Italy, acquired from the USDA collection
at Aberdeen, ID, are being evaluated for Type II resistance under
single floret inoculation. A number of accessions with resistance
apparently equal to or better than Sumai 3 have been identified
through a preliminary screen. Once verified, data will be submitted
to GRIN and shared with breeders in the winter wheat region. Accessions
will be evaluated in the field for Type I resistance and kernel
quality during the 1999 crop season. In addition, agronomic data
will be collected for disease resistances and traits related to
midwest adaptation.
Studies on the stability of resistances in different wheat genetic
backgrounds are proceeding using a diverse array of five isolates
from the eastern United States. Isolates from Missouri, Indiana,
Ohio, Michigan, and Virginia are being tested against 28 entries
in the 1999 Winter Wheat Fusarium Head Blight Nursery. Resistance
will be analyzed for stability across isolates. In addition, genotype
by isolate interactions will be evaluated.
Conventional and molecular genetic studies of the scab resistance
identified in the SRWW Ernie are ongoing. A set of recombinant
inbred lines has been developed from the cross 'Ernie (resistant)
/ MO 94- 317(susceptible)' and will be used as a mapping population
to tag resistance genes in Ernie. Crosses with theChinese Spring
monosomic series are underway to determine chromosome locations
of resistance genes.
Visiting scientists.
Z. Wang, and M. Xie, from P.R. China, and B. Kim, Korea.
Publications.
Chen J and Gustafson JP. 1997. Study on chromosomal rearrangement
of wheat (T. aestivum) chromosome 4A by in situ hybridization.
Acta Genet Sin 24:141-148.
Chen J and Gustafson JP. 1997. Chromosomal rearrangement of wheat
(T. aestivum) chromosome 4A by in situ hybridization. Chinese
J Genet 24:39-47.
Houchins K, O'Dell M, Flavell RB, and Gustafson JP. 1997. Cytosine
methylation and nucleolar dominance in cereal hybrids. Mol Gen
Genet 25:294-301.
McKendry AL, Sweets LE, Wright RL, Tague DN, and Mattas RE. 1998.
1998 Missouri Winter Wheat Performance Tests. Special Report 512.
Missouri Agricultural Experiment Station. College of Agriculture,
Food and Natural Resources. University of Missouri-Columbia.
Moore G and Gustafson JP. 1996 Comparative analysis of cereal
genomes. In: DNA markers: Protocols, Applications and Overviews
(Caetano-Anoll's and Gresshoff eds). J Wiley & Sons, Inc.
Wanous MK, Snape JW, and Gustafson JP. 1996. Factors influencing
efficiency of genetic mapping projects. Maize Genet Newslet 71:28-29.