Annual Reports 1994-1997

 

PROCEEDINGS OF A JOINT MEETING OF SOUTHERN REGIONAL

INFORMATION EXCHANGE GROUP-51 AND COOPERATIVE

REGIONAL PROJECT NC-129

 

Holiday Inn-Atlanta Airport North: January 20-21, 1997

 

State/Agency Reports	Return to SRIEG-51 home page	Business Meeting
		List of Attendees

 

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Annual meetings of SRIEG-51 and NC-129 were held together on January 20-21, 1997, at the Holiday Inn-Atlanta Airport North.  The meeting was called to order by NC-129 Chairman Gavin Meerdink at

10:00 AM.

 

Chairman Meerdink welcomed everyone to the meeting and thanked SRIEG-51 Chairman Barbara Kemppainen for handling the local arrangements.  He then introduced William Wagner (USDA) and asked him to make a few comments to the group.  Dr. Wagner discussed the status of Regional Projects as a whole and how they might evolve in the future to stretch across regions.  No information was available on USDA’s budget, but Dr. Wagner did provide information on the Fund for Rural America.

 

 

State/Agency Reports

ALABAMA

N.K. Gurung reported the effect of cation concentrations on production of fumonisin B1 (FB1) in liquid medium.  Several cations had a significant effect on mycelial growth and also on production of FB1.  Constant shaking of the cultures was essential for FB1 production.

Kira Bowen reported on the biological control of Aspergillus flavus on peanut.  Work at Dawson, GA, showed that selected bacterial strains could limit A. flavus invasion of peanut and also reduce aflatoxin levels. Bruce Manning reported on the effect of FB1 on the growth of channel catfish and related sphinganine:sphingosine ratios.  Results varied when Fusarium culture material was used instead of pure FB1.

ARS

Chris Maragos summarized the work conducted on mycotoxins at Peoria by sixteen ARS scientists.  Products contaminated with fumonisins after dry milling were identified.  New technologies have been developed for more efficient detection of mycotoxins in foods.  Bioassays have been developed for isolating Fusarium toxins and for further assessment of known toxins.  Indirect resistance to Fusarium was observed with a commercial corn hybrid.  Fusarium genes involved in mycotoxin synthesis have been isolated and characterized.

GEORGIA

Dave Wilson discussed progress made using a norsolorinic acid producing A. parasiticus mutant to develop a screening method for resistance to preharvest aflatoxin contamination of corn.

Neil Widstrom presented the results of a corn survey for aflatoxin in 1996.  The mean aflatoxin contamination of irrigated fields was 32 ppb and the mean for dryland corn was 67 ppb, while the overall mean was 49 ppb.  Studies in cooperation with David Wilson show that an A. parasiticus mutant may provide a cost-saving marker for identifying susceptible genotypes.

Ron Riley reported on various research projects on mycotoxins at the ARS Russell Research Lab in Athens.  Results from tests on the toxicology of fumonisins on various test animals were presented.  Research is being conducted to understand the interactions of mycotoxins using rats as a model system.

ILLINOIS

Gavin Meerdink discussed the effects of sublethal concentrations of fumonisins on animals.  Results from the diagnostic lab on mycotoxin levels over the 1990’s were presented.  From 1990-1993, higher levels of aflatoxin were reported, while lower levels were seen from 1994-1996.  Higher levels of aflatoxin were associated with late planting dates in 1991 and the floods of 1993.  Vomitoxin levels fluctuate from year to year with no real trend.  Fumonisin levels are relatively stable from year to year at the 1-5 ppm level.  Sample numbers processed by the diagnostic lab are decreasing due to the increased use of commercial test kits.

INDIANA

Charles Woloshuk presented the results of surveys on ear rots and the distribution of Fusarium spp. in corn fields.  Fusarium ear rots were the most common in 1996, followed by Gibberella and Diplodia ear rots.  Aspergillus ear rots were not observed in 1996.  Fusarium moniliforme was the most common species isolated from fields in 1996, followed by subglutinans and graminearum.  Fusarium prolferatum was not isolated from any of the fields.  Woloshuk also discussed his work on the biosynthesis of fumonisins.

IOWA

Patricia Murphy reported on work with derivatives of fumonisins that normally occur in foods.

Mike Stahr discussed the new mycotoxin, fusaproliferin, produced by the Fusarium proliferatum.  The problem of variation in quantification of mycotoxins among diagnostic labs was discussed.

LOUISIANA

Robert Brown discussed the results from research projects at the Southern Regional Research Lab at New Orleans.  A lab assay for identifying corn genotypes with resistance to Aspergillus flavus has been developed.  Findings from the lab assay generally agree with results in field screenings.  A transformed isolate of A. flavus has been used to determine fungal infection.  Waxes covering kernels have been quantified in an effort to discover resistance mechanisms.  Proteins specific for resistant corn have been isolated.  Cooperative research with ARS scientists at Miss. State, MS, is planned for 1997.

MICHIGAN

Pat Hart reported progress made on developing new techniques for quantification of fumonisins and zearalenone.  Head blight was a severe problem in Michigan wheat in 1996.  DON was detected in wheat samples throughout the state with levels of 2-10 ppm being common.  Two cereal companies refused to accept any Michigan wheat due to the head blight problem.  The results of a sampling study for DON in wheat was discussed.

MINNESOTA

Chester Mirocha submitted a report on research being conducted on fumonisins, AAL, and DON at the University of Minnesota.  A survey of wheat and barley in the Red River Valley indicated that Fusarium head blight was not a serious problem in 1996.  The 7-deoxynivalenol isomer of DON has been found in some wheat samples.  A method has been developed for the identification of DON derivatives by mass spectrometry.  Barley inoculated with F. graminearum tested positive for DON at 48 hours following inoculation.  Amounts of DON steadily increased from two to ten days post inoculation.

MISSOURI

George Rottinghaus discussed the use of mixed solid phase cleanup columns in removing pigments from samples.  This technique uses a minimal amount of water.  A rapid TLC screen and a HPLC analysis of monilifomin were discussed.  Preliminary results from a 1996 survey of corn for monilifomin and fumonisin B1 were reported.  Monilifomin was found at the 1-2 ppm level in 21% of the samples and 16% of the samples had moniliformin at > 2 ppm.  Fumonisins were found in only 16% of the samples.

David Ledoux reported on the toxicity of fumonisin B1 to broiler chicks, turkey poults, and ducklings.  FB1 was not lethal to any of these avian specias at the 50 mg/kg level.  These results indicate that FB1 may not be of practical concern to the poultry industry.  Studies are being conducted to determine the effects of chronic exposure of avian spp. to FB1.  Fungal culture material continues to be more potent than pure FB1.

Marty Dickman discussed his research on host-parasite interactions which focus primarily on mechanisms of pathogenesis.  The effect of fumonisins on apoptosis was reported.

NORTH CAROLINA

Gary Payne discussed the characterization of compounds inhibitory to aflatoxin formation.  An assay in microtiter dishes is being used and correlates well with field results.  Two proteins have been identified that block fungal growth and inhibit aflatoxin synthesis.

NORTH DAKOTA

Howard Casper reported that DON continues to be a problem in North Dakota.  A major epidemic occurred in 1993 and DON has been a problem for growers for the last four years.  Diagnostic services at NDSU have handled 5500 samples in the last five years with 2000 of those samples testing positive for mycotoxins.

WISCONSIN

Weidong Wu reported on studies correlating duckling toxicity and mycotoxin concentration in culture material.  Fusarium moniliforme  isolates produced monilifomin or fumonisin B1, but not both.  However, two F. proliferatum  isolates produced both mycotoxins.

F.S. Chu discussed the use of antibodies for controlling aflatoxin formation.  Data from the immunochemical analysis of AFLR in fungal culture have shown that immunochemical methods may become effective tools in identifying various factors and agents that could control aflatoxin formation.

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ATTENDEES

 

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