ITEMS FROM THE UNITED STATES

MISSOURI

UNIVERSITY OF MISSOURI

Department of Agronomy and the USDA-ARS, Curtis Hall, Columbia, MO 65211, USA.

http://www.ext.missouri.edu/agebb/cropperf/wheat

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.

Personnel.

Kara Salzman joined the wheat breeding program as a research specialist working to identify new sources of resistance to FHB in winter wheat.

1999 Missouri winter wheat crop.

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 group.

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

Wheat genetics research.

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.

Fusarium head blight research.

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 2).

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 resistance.

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:

• 1. Disease spread in the head # 2 spikelets.
• 2. A low kernel-quality score based on the 5-point scale outlined above. Lines are retained when the majority of the kernels had a score of 1 on this scale.
• 3. High kernel retention (> 75 % compared to an uninoculated head).

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 of 2000-01.

Publications.

• Darvey NL, Gustafson JP, and Naeem H. 1999. Triticale: production and utilization. In: Handbook of Cereal Science and Technology (Kulp K and Ponte JG eds). Marcel Dekker, Inc. New York.
• Dimitrijevic D, Petrovic S, and Gustafson JP. 2000. The presence of 1BL·1RS wheat/rye translocation in wheat of Serbia. In: Proc 6th Internat Wheat Conf, Budapest, Hungary, June 2000.
• Guedes Pinto H, Casas L, Silva C, and Gustafson JP. 1999. Triticale x rye crossability. J Plant Breed (in press).
• Gustafson JP (ed). 2000. Genomes, Proc 22nd Stadler Genetics Symp 1999. Plenum Press (in press).
• Gustafson JP and Yano M. 2000. Genetic mapping of hypervariable minisatellite sequences in rice (Oryza sativa L.). 1999. Theor Appl Genet (in press).
• Gustafson JP and Yano M. 2000. DNA fingerprinting and genetic mapping of minisatellite sequences in rice. In: Mutation techniques and molecular genetics for tropical and subtropical plant improvement in Asia and the Pacific region. FAO/IAEA. Philippines (in press).
• Kim BY, Baier AC, Somers DJ, and Gustafson JP. 2000. Aluminum tolerance in triticale, wheat, and rye. In: Radiation induced mutations and other advanced technologies for the production of seed crop mutants suitable for environmentally sustainable agriculture (Maluszynski M ed). (In press).
• Kim BY, Gustafson JP, and Ross K. 2000. Aluminum tolerance. In: Cereals. MIAC Meeting, Guadalajara, Mexico. (In press).
• McKendry AL, Sweets LE, Wright RL, Tague DN, Salzman KS, and Mattas RE. 1999. 1999 Missouri Winter Wheat Performance Tests. Special Report 526, Missouri Agricultural Experiment Station, College of Agriculture, Food and Natural Resources, University of Missouri-Columbia. 32 pp.
• Scoles G, McLeod G, and Gustafson JP. 2000. Rye: genetics and breeding. In: Rye: production, chemistry, and technology (Bushuk W ed). (In press).
• Szarejko I and Gustafson JP. 2000. DNA fingerprinting in barley. In: Radiation induced mutations and other advanced technologies for the production of seed crop mutants suitable for environmentally sustainable agriculture (Maluszynski M ed). (In press).