Source: KANSAS STATE UNIV submitted to
GENETICS AND PHYSIOLOGY OF FUSARIUM SSP
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0188691
Grant No.
(N/A)
Project No.
KS601
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2001
Project End Date
Sep 30, 2006
Grant Year
(N/A)
Project Director
Leslie, J. F.
Recipient Organization
KANSAS STATE UNIV
(N/A)
MANHATTAN,KS 66506
Performing Department
PLANT PATHOLOGY
Non Technical Summary
Fusarium spp. are amongst the most widespread of all fungal plant pathogens. In Kansas the crops most significantly impacted are wheat, maize and sorghum. Losses due to these fungi come in two forms. First there are direct losses due to disease that result in lower total yields. Of equal, or greater importance, however, are losses in quality due to contami-nation of grain with mycotoxins that are harmful both to humans and to domesticated animals.
Animal Health Component
(N/A)
Research Effort Categories
Basic
100%
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21240201102100%
Knowledge Area
212 - Pathogens and Nematodes Affecting Plants;

Subject Of Investigation
4020 - Fungi;

Field Of Science
1102 - Mycology;
Goals / Objectives
Project 1.Genetics of Fusarium verticillioides; Genetic map Increase number of markers and map phenotypically important markers. Chromosome 12 Identify polymorphic chromosomes from field populations; screen strains carrying different chromosomes for economic traits, changes in pathogenicity and or ability to produce mycotoxins. Vegetative compatibility. Mapping vic genes and other genes that alter vegetative compatibility; recovery of new mutants with altered phenotypes; identification of genes differentially regulated in mutant and wild type strains. Project 2.Genetics of Fusarium graminearum. Develop protocol to identify chromosome rearrangements in raw mapping data. Develop standard Normal Sequence genetic map to which other genome organizations in this species can be compared. Increase collection size and diversity in terms of geographic and host origin. Determine relatedness of domestic and foreign populations. Project 3. Taxonomy and Population Studies of Fusarium spp. Increase collection size and diversity in terms of geographic and host origin. Develop species specific PCR markers for major species from maize, sorghum and wheat, and standard mating type tester strains for all species for which a sexual stage can be identified in the laboratory. Describe new species and new mating populations. Project 4.Mycoviruses in Fusarium spp. Screen over 1000 isolates from F. graminearum, F. verticillioides, F. proliferatum, and F. thapsinum for the presence of dsRNA mycoviruses. Determine the means of transmission of these viruses and their subcellular locations. Determine if strains carrying mycoviruses are altered in pathogenicity towards wheat, maize or sorghum, or in their ability to produce mycotoxins, fumonisins, zearalenone, and trichothecenes. Project 5. Fusarium Laboratory Workshop. Attendance at the workshop is limited to 32 participants, due to limitations in the number of microscopes and the equipment available for the molecular biology analyses.
Project Methods
Project 1: Genetics of Fusarium verticillioides a.Description: We are making genetic maps of this organism and studying the basic process of vegetative incompatibility in it. We have constructed a genetic map with 12 linkage groups, which correspond to 12 chromosomes identified through pulsed field gel electrophoresis. Molecular markers and classical markers are included in the map, which is essential for the identification of the genes that govern the vegetative incompatibility process (vic loci). Vegetative incompatibility is a means by which fungi distinguish self from non-self. We have identified genetic components of the system and are now beginning to discern its molecular basi. Project 2: Genetics of Fusarium graminearum a.Description: Fusarium graminearum, also known as Gibberella zeae, causes wheat scab and corn ear and stalk rot. It pro-duces zearalenone and trichothecene mycotoxins and can cause economic losses due to reduction in yield or to reduction in value due to mycotoxin contamination. Studies have focused on developing classical genetic tools and maps, and in identify-ing the amount of genetic variation in field populations of the disease and between geographically separated populations. A genetic map is an essential research tool for studying an organism and commonly forms the basis for molecular and population genetic data analyses. Project 3: Taxonomy and Population Studies of Fusarium spp. a.Description: We are evaluating populations of Fusarium from various crops with a focus on maize and sorghum. Project 4: Mycoviruses in Fusarium spp. a. Description: We will screen a collection of over 500 isolates of F. graminearum and another collection of up to 500 isolates of F. verticillioides, F. proliferatum, and F. thapsinum collected from wheat, corn and sorghum grown primarily in Kansas. The double-stranded RNA molecules (dsRNAs) will be characterized as to the number of molecules they contain, and some will be sequenced to assist in determining their related ness to one another.

Progress 10/01/01 to 09/30/06

Outputs
We identified several new Fusarium-related species, including Fusarium andiyazi, Fusarium konza and Gibberella sacchari, as well as identifying what appear to be naturally occurring hybrids between two well-established species from the Konza prairie. In general strains recovered from natural areas were found to be similar to other members of the same species and to produce similar levels of mycotoxins as those found in agricultural fields. Fusarium spp. from sorghum are much more complex than those recovered from maize, with at least five different species identified and many isolates remaining unassigned to any species. These species differ in toxin production and in pathogenicity and their discrimination will be essential to advance breeding programs for resistance to sorghum stalk rot and grain mold. Genetic maps have been prepared and updated for F. verticillioides and F. graminearum. The first assessment of QTL data for mapping aggressiveness in a fungal plant pathogen also was conducted, with a single QTL that overlaps the trichothecene mycotoxin gene cluster in F. graminearum identified. Population genetic studies of F. graminearum found that these populations were very diverse and that this diversity is widely and more-or-less uniformly distributed from Montana to Virginia and New York both on the ground and in the air. The differences between local populations were small enough that they may represent the diffusion time that it takes for various alleles to move from one location to another as population differences in genetic distance and geographic distance were significantly correlated. All populations of F. graminearum were composed of lineage 7 isolates indicating that this lineage is the major, if not the only, lineage of this pathogen present in the United States.

Impacts
Fusarium spp. cause billions of dollars of losses to crops both in the United States and worldwide. Identification of these fungi is difficult, but essential, to understand the risks that they pose as mycotoxin producers or import threats and to ensure that new lines are challenged with the correct pathogen. Grasslands could be an important refugia for Fusarium species and new hybrids and species of economic importance may be developing there. The numerous Fusarium species found in sorghum are probably slowing breeding efforts for stalk rot and grain mold resistance due to the difficulty in consistently challenging new material with the same set of pathogens on a routine basis. The genetic maps developed are critical to efforts to sequence the genomes of these fungi and to identify genes in these fungi that are of critical importance for pathogenicity. The distribution of genetic variation in air and field populations of F. graminearum is such that differences in disease incidence across the Northern United States are probably due to differences in local conditions rather than to differences in pathogen population composition. The Fusarium Laboratory workshops have become a very important outreach tool. By holding them throughout the world, but with central coordination provided from K-State, these workshops draw participants from many countries and unite the community in terms of communication and strain distribution. The newly published Fusarium Laboratory Manual is the first in the area in 23 years and replaces an old standard that was becoming rather seriously dated.

Publications

  • Leslie, J. F. 2001. Population genetic level problems in the Gibberella fujikuroi species complex. In: Fusarium: Paul E. Nelson Memorial Symposium (B. A. Summerell, J. F. Leslie, D. Backhouse, W. L. Bryden & L. W. Burgess, eds.), pp. 113-121. APS Press, St. Paul, Minnesota.
  • Leslie, J. F. & W. F. O. Marasas. 2001. Fusarium in sorghum: Life in interesting times. Proceedings of the 22nd Sorghum Improvement Conference of North America (Nashville, Tennessee), pp. 76-83.
  • Leslie, J. F., K. A. Zeller & B. A. Summerell. 2001. Icebergs and species in populations of Fusarium. Physiological and Molecular Plant Pathology 59: 107-117.
  • Marasas, W. F. O., J. P. Rheeder, S. C. Lamprecht, K. A. Zeller & J. F. Leslie. 2001. Fusarium andiyazi sp. nov., a new species from sorghum. Mycologia 93: 1203-1210.
  • Summerell, B. A., J. F. Leslie, D. Backhouse, W. L. Bryden & L. W. Burgess, eds. 2001. Fusarium: Paul E. Nelson Memorial Symposium. APS Press, St. Paul, Minnesota. 392 pp.
  • Fotso, J., J. F. Leslie & J. S. Smith. 2002. Production of beauvericin, moniliformin, fusaproliferin, and fumonisins B1, B2 and B3 by ex-type strains of fifteen Fusarium species. Applied and Environmental Microbiology 68: 5195-5197.
  • Jurgenson, J. E., R. L. Bowden, K. A. Zeller, J. F. Leslie, N. J. Alexander & R. D. Plattner. 2002. A genetic map of Gibberella zeae (Fusarium graminearum). Genetics 160: 1452-1460.
  • Jurgenson, J. E., K. A. Zeller & J. F. Leslie. 2002. An expanded genetic map of Gibberella moniliformis (Fusarium verticillioides). Applied and Environmental Microbiology 68: 1972-1979.
  • Leslie, J. F., ed. 2002. Sorghum and Millets Diseases. Iowa State Press, Ames, Iowa. 504 pp.
  • Leslie, J. F. & W. F. O. Marasas. 2002. Will the real Fusarium moniliforme please stand up! In: Sorghum and Millets Diseases (J. F. Leslie, ed.), pp. 201-209. Iowa State Press, Ames, Iowa.
  • Porter, J. K., C. W. Bacon, W. P. Norred, E. M. Wray, G. A. Kuldau, A. E. Glenn, & J. F. Leslie. 2002. Mycotoxins from fungal-infected sorghum: Claviceps vs. Fusarium and the Striga connection. In: Sorghum and Millets Pathology (J. F. Leslie, ed.), pp. 229-235. Iowa State Press, Ames, Iowa. 516 pp.
  • Seifert, K. A., T. Aoki, R. P. Baayen, D. Brayford, L. W. Burgess, S. Chulze, W. Gams, D. Geiser, J. de Gruyter, J. F. Leslie, A. Logrieco, W. F. O. Marasas, H. I. Nirenberg, K. O Donnell, J. P. Rheeder, G. J. Samuels, B. A. Summerell, U. Thrane and C. Waalwijk. 2003. The name Fusarium moniliforme should no longer be used. Mycological Research 107: 643-644.
  • Summerell, B. A., B. Salleh & J. F. Leslie. 2003. A utilitarian approach to Fusarium identification. Plant Disease 87: 117-128.
  • Wu, X., J. F. Leslie, R. A. Thakur & J. S. Smith. 2003. Preparation of a fusaproliferin standard from the culture of Fusarium subglutinans E-1583 by high performance liquid chromatography. Journal of Food and Agricultural Chemistry 51: 383-388.
  • Zeller, K. A., R. L. Bowden & J. F. Leslie. 2003. Diversity of epidemic populations of Gibberella zeae from small quadrats in Kansas and North Dakota. Phytopathology 93: 874-880.
  • Zeller, K. A., B. A. Summerell, S. Bullock & J. F. Leslie. 2003. Gibberella konza (Fusarium konzum) sp. nov., a new biological species within the Gibberella fujikuroi species complex from prairie grass. Mycologia 95: 943-954.


Progress 01/01/05 to 12/31/05

Outputs
Identification and description of Fusarium species remains important as many previously large species are being subdivided into smaller units. Species definitions also may vary depending on the species concept involved morphological, biological or phylogenetic. Traditionally morphological has dominated (and usually results in the fewest species), while phylogenetic approaches (which usually result in the most species) are becoming more common. We formally described a species from sugar cane that has been known previously under another name and showed that it also could be a significant problem on sorghum. We also characterized strains from sorghum and millet that had all been termed Fusarium moniliforme and found that these strains can be resolved into at least five different species F. verticillioides, F. thapsinum, F. nygamai, F. pseudonygamai, and F. andiyazi. These species differ in pathogenicity (F. thapsinum is most pathogenic on sorghum, and in the spectrum of toxins they produce. Based on molecular data we think that strains presently termed F. nygamai probably should be separated into at least two additional species. The confusion resulting from this confounding of different species is one reason why it has been difficult to breed for resistance to the stalk rot and grain mold diseases of sorghum with which these species are associated. We confirmed the production of fumonisin C by several strains of F. oxysporum. The pathogen is not usually associated with mycotoxin production. Its ability to produce fumonisin C is thus disconcerting as it means that these toxins may be able to enter the food/feed chain through fruits and vegetables that were previously not thought to suffer from serious mycotoxin contamination problems.

Impacts
Fusarium spp. causes billions of dollars of losses to crops both in the United States and worldwide. Identification of these fungi is difficult, but essential, to understand the risks that they pose as mycotoxin producers or import threats and to ensure that new lines are challenged with the correct pathogen. We described a new species known best from sugarcane that also can attack sorghum. We also evaluated a series of five species from sorghum and millet and showed that what was once called a single entity is at least five different species. These species differ in their plant pathogenicity and the mycotoxins they produce. The resolution of these species should enable targeted breeding for resistance to grain mold and stalk rot in sorghum. The identification of strains that produce high levels of moniliformin as common contaminants of pearl millet means that the use of this grain as poultry feed needs to be monitored since most poultry are quite sensitive to moniliformin. Fusarium oxysporum is one of the most widespread of the Fusarium species, being found in most soils and as a causal agent for diseases of horticultural and vegetable crops. In general this fungus is not viewed as a mycotoxin-producing threat. Our finding that strains of F. oxysporum can synthesize fumonisin C suggests that fumonisins, which are associated with esophageal cancer and neural tube defects in humans and are toxic to many domesticated animals, could be entering the food/feed chain through a source other than the cereal grains, especially maize, with which they are traditionally associated.

Publications

  • Leslie, J. F., B. A. Summerell, S. Bullock & F. J. Doe. 2005. Description of Gibberella sacchari and neotypification of its anamorph Fusarium sacchari. Mycologia 97: 718-724.
  • Leslie, J. F., K. A. Zeller, S. C. Lamprecht, J. P. Rheeder & W. F. O. Marasas. 2005. Toxicity, pathogenicity and genetic differentiation of five species of Fusarium from sorghum and millet. Phytopathology 95: 275-283.
  • Sewram, V., N. Mshicileli, G. S. Shephard, H. F. Vismer, J. P. Rheeder, Y.-W. Lee, J. F. Leslie & W. F. O. Marasas. 2005. Production of fumonisin B and C analogs by several Fusarium species. Journal of Agricultural and Food Chemistry 53:4861-4866.


Progress 01/01/04 to 12/31/04

Outputs
Identification and description of Fusarium species remains important as many previously large species are being subdivided into smaller units. Species definitions also may vary depending on the species concept involved morphological, biological or phylogenetic. Traditionally morphological has dominated (and usually results in the fewest species), while phylogenetic approaches (which usually result in the most species) are becoming more common. We have isolated and characterized strains that appear to be inter-specific hybrids from the Konza prairie biological station, a result that suggest that rare, but evolutionarily significant changes in agriculturally important pathogens could be occurring in native grasslands. Population genetic studies with Gibberella zeae (Fusarium graminearum) showed that populations from Montana to Virginia represent a single panmictic population. There was a correlation between genetic distance and geographic distance that probably is indicative of the diffusion time between the various populations. Fungal populations across this region all contain > 90% of the variation contained in the continental meta-population, so differences in resistance to this pathogen are likely to be due to local environmental conditions rather than to differences in the genetic composition of the fungal population. We also evaluated aggressiveness of G. zeae against wheat in a QTL analysis of the mapping population on which our genetic map of G. zeae is based. This is the first QTL analysis in a filamentous fungus. We found that there was only a single QTL in this cross, and that this QTL was associated with the trichothecene gene cluster; trichothecene production has previously been reported to be a pathogenicity determinant in the wheat/G. zeae interaction. Zearalenone is an estrogenic metabolite often regulated in international trade. This compound is not produced by fungi in the Liseola section of the genus, which often is associated with sorghum. Often these tests are made with thin layer chromatography. We found strains from this section that appeared to be positive for zearalenone production were producing another compound, 8-bostrycoidin, instead of zearalenone. These compounds migrate at similar positions on TLC but can be easily separated if more sophisticated chemical analysis techniques are used.

Impacts
Fusarium spp. cause billions of dollars of losses to crops in the United States and throughout the world. Identification of these fungi is difficult, but essential, to understand the risks that they pose as mycotoxin producers or import threats and to ensure that new lines are challenged with the correct pathogen. For example, if G. zeae is present as a continent-wide panmictic population, it means that most of the wheat and barley hosts in field trials are exposed to a similar pathogen population and that differences between locations probably are not due to differences in the pathogen population. Fusarium spp. from native grasses may be of particular importance in understanding how these pathogens have evolved and are just now beginning to be studied. The numerous secondary metabolites made by these fungi often have been evaluated only in crude extracts due to inadequate practical chemical protocols for their purification.

Publications

  • Cumagun, C. J. R., Bowden, R. L., Jurgenson, J. E., Leslie, J.F., and Miedaner, T. 2004. Genetic mapping of pathogenicity and aggressiveness of Gibberella zeae (Fusarium graminearum) towards wheat. Phytopathology 94: 520-526.


Progress 01/01/03 to 12/31/03

Outputs
Identification and description of Fusarium species remains important as many previously large species are being subdivided into smaller units. Species definitions also may vary depending on the species concept involved, morphological, biological or phylogenetic. Traditionally morphological has dominated (and usually results in the fewest species), while phylogenetic approaches (which usually result in the most species) are becoming more common. We have developed measures and guidelines for implementing these species concepts when different approaches appear to give different answers. The name for one of the formerly monolithic species groups, Fusarium moniliforme, has now been officially retired. A new species, known so far only from the native grasses found on the Konza prairie biological station, has now been described, with the AFLP criterion of > 65-70% similarity within a species and < 40% similarity between species used as an important criterion. Population genetic studies with Gibberella zeae (Fusarium graminearum) showed that populations from Kansas and North Dakota were very simple, suggesting that this species might be represented by a single panmictic population in North America. Fusaproliferin is a secondary metabolite whose importance as a toxin has not been adequately tested. The newly developed purification protocol will allow larger quantities of this compound that are free of many contaminants to be available for tests in model and economically important systems.

Impacts
Fusarium spp. causes billions of dollars of losses to crops in the United States and throughout the world. Identification of these fungi is difficult, but essential, to understand the risks that they pose as mycotoxin producers or import threats and to ensure that new lines are challenged with the correct pathogen.

Publications

  • Zeller, K. A., B. A. Summerell, S. Bullock, and J. F. Leslie. 2003. Gibberella konza (Fusarium konzum) sp. nov., a new biological species within the Gibberella fujikuroi species complex from prairie grass. Mycologia 95: 943-954.
  • Seifert, K. A., T. Aoki, R. P. Baayen, D. Brayford, L. W. Burgess, S. Chulze, W. Gams, D. Geiser, J. de Gruyter, J. F. Leslie, A. Logrieco, W. F. O. Marasas, H. I. Nirenberg, K. O Donnell, J. P. Rheeder, G. J. Samuels, B. A. Summerell, U. Thrane, and C. Waalwijk. 2003. The name Fusarium moniliforme should no longer be used. Mycological Research 107: 643-644.
  • Summerell, B. A., B. Salleh, and J. F. Leslie. 2003. A utilitarian approach to Fusarium identification. Plant Disease 87: 117-128.
  • Wu, X., J. F. Leslie, R. A. Thakur, and J. S. Smith. 2003. Preparation of a fusaproliferin standard from the culture of Fusarium subglutinans E-1583 by high performance liquid chromatography. Journal of Food and Agricultural Chemistry 51: 383-388.
  • Zeller, K. A., R. L. Bowden, and J. F. Leslie. 2003. Diversity of epidemic populations of Gibberella zeae from small quadrats in Kansas and North Dakota. Phytopathology 93: 874-880.


Progress 01/01/02 to 12/31/02

Outputs
Identification and description of Fusarium species remains of importance as many previously monolithic blocks are being found to be composed of a number of genetically discrete units. We evaluated 15 ex-type strains from newly described species for the ability to produce fumonisins, moniliformin, beauvericin and fusaproliferin when cultured on corn grits. Fumonisins were produced by five species, fusaproliferin by three species, beauvericin by five species, and moniliformin by eight species. None of the species examined produced fumonisin B3. F. bulbicola was the only one of the 15 species examined that produced none of these toxins. Genetic maps are well-developed for only a handful of filamentous fungi. We developed the first map for Gibberella zeae (Fusarium graminearum) and extended the existing map of Gibberella moniliformis (Fusarium verticillioides). The G. zeae map carries more that 1000 markers on nine chromosomes defined by over 500 loci. Two putative chromosome rearrange-ments also were identified, and the trichothecene biosynthetic gene cluster was localized as well as the gene controlling the production of either nivalenol or deoxynivalenol. The G. monili-formis map is not as heavily saturated, but all previously identified fragments that were associ-ated with a chromosome based on CHEF gel hybridization are now connected to the same link-age group. A modified bulk-segregant analysis protocol was developed to identify AFLP mark-ers associated with the fumonisin biosynthetic gene cluster.

Impacts
Fusarium spp. cause billions of dollars of losses to crops in the United States and throughout the world. Identification of these fungi is difficult, but essential, to understand the risks that they pose as mycotoxin producers, import threats and to ensure new lines are challenged with the correct pathogen. Fusarium spp. from sorghum and millets have been particularly recalcitrant. The genetic maps are essential for forward genetics, and can be used to study QTLs for virulence and mycotoxin production, and to localize naturally occurring genetic variants for analysis through genomic studies that are already in progress.

Publications

  • Fotso, J., J. F. Leslie & J. S. Smith. 2002. Production of beauvericin, moniliformin, fusapro-liferin, and fumonisins B1, B2 and B3 by ex-type strains of fifteen Fusarium species. Applied and Environmental Microbiology 68: 5195-5197.
  • Jurgenson, J. E., R. L. Bowden, K. A. Zeller, J. F. Leslie, N. J. Alexander & R. D. Plattner. 2002. A genetic map of Gibberella zeae (Fusarium graminearum). Genetics 160: 1452-1460.
  • Jurgenson, J. E., K. A. Zeller & J. F. Leslie. 2002. An expanded genetic map of Gibberella moniliformis (Fusarium verticillioides). Applied and Environmental Microbiology 68: 1972-1979.
  • Leslie, J. F., ed. 2002. Sorghum and Millets Diseases. Iowa State Press, Ames, Iowa. 516 pp.
  • Leslie, J. F. & W. F. O. Marasas. 2002. Will the real Fusarium moniliforme please stand up! In: Sorghum and Millets Diseases (J. F. Leslie, ed.), pp. 201-209. Iowa State Press, Ames, Iowa. 516 pp.


Progress 01/01/01 to 12/31/01

Outputs
We are assessing genetic diversity in populations of several Fusarium species including F. verticillioides, F. proliferatum, and F. graminearum. In all cases the populations appear to have relatively little linkage disequilibrium, suggesting that these populations have been established for an extended period of time. A number of species have been described recently in the Gibberella fujikuroi species complex. We have been examining these species for production of fumonisins, beauvericin, fusaproliferin, moniliformin, and fusaric acid. Most of the fifteen species we examined make at least one of these toxins. Fungal hypoviruses can limit the virulence of strains that they infect. We are surveying F. proliferatum and F. graminearum for double-stranded RNA (dsRNA) molecules, which are the form taken by these viruses. We have found some apparently multi-partite viruses in both species. None of these viruses have obvious effects on colony morphology when cultured in the laboratory. Some of the viruses appear to be located in the mitochondria and cannot be passed to progeny if the male parent carries the virus. All cured strains are not fertile as female parents, so it has not been possible to determine if the viruses repress female fertility, as has been reported in other fungi.

Impacts
Genetic diversity is an important parameter in fungal populations. A stable population with little linkage disequilibrium is unlikely to change rapidly in response to changes in its environment or available host. It also is likely to have already sorted out most of the possible genotypes that are possible and selection for a particular genotype could occur relatively rapidly. Mycotoxins are a major threat to grains and other foodstuffs contaminated with Fusarium spp. As new species are identified it is important to evaluate their ability to synthesize various mycotoxins to determine the risk posed by these strains to both humans and domesticated animals. Fungal hypoviruses have been studied in only a few systems and are potential sustainable biological controls of Fusarium diseases.

Publications

  • No publications reported this period