Grain Fungal Diseases And Mycotoxin Reference

United States Department of Agriculture Grain Inspection, Packers and Stockyards Administration Federal Grain Inspection Service STOP 3630 Washington, D.C. 20250-3630 Grain Fungal Diseases and Mycotoxin Reference Forward This manuscript is a compilation of information that has been available for some time. We will try to present this information in a way that will be helpful to non-specialists in an easy to digest manner. The nature of this information tends towards the technical and sometimes keeps needed information out of the reach of those that could use it most. We will try to keep this in mind while presenting the needed information. Also, while not being technically correct, we have kept reference citations to a minimum, and have inserted numbers, i.e.: [23], to keep the interruptions to the flow ideas as few as possible. Contents Fungi and Fungal Diseases of Plants Definition and Overview Non-Mycotoxic Fungi Common Smut or Bunt. Dwarf Bunt or TCK Smut. Karnal Bunt. Black Tip / Black Point. Blue-Eye Rot. Corn Smut. What Are Mycotoxins? Background. Economic effects. Health Hazards. Lack of Regulatory and Monitoring systems. Regulatory Control. Aspergillus Toxins Penicillium Toxins Fusarium Toxins Alternaria Toxins Claviceps Toxins Contents cont’ Mycotoxins in Grain and Feed Aflatoxin Ergot Trichothecenes Deoxynivalenol (DON) Zearalenone (ZEN) Fumonisin Nivalenol (NIV) Ochratoxin T-2 Cyclopiazonic Acid (CPA) Citrinin Glossary References Fact Sheets Aspergillus Ear Rot Black Tip / Black Point Blue-Eye Mold Ergot Fusarium Ear Rot Gibberella Ear Rot Karnal Bunt Scab (Head Blight) TCK Smut (Dwarf Bunt) Fungi and Fungal Diseases of Plants Definition and Overview. Fungi are probably one of the most numerous plant families on earth. By definition they are plants that contain no chlorophyll (can grow in conditions of little or no natural light) and range from single cells to a body of branched hyphae (tubular filaments) that often produce fruiting bodies that form molds, mushrooms, smuts and yeasts. Instead of producing their own food, fungi absorb nutrients from either a living or dead host material. Symptoms and disease development come about from the growth of the fungi through the host-parasite interaction. These fungi sometimes produce metabolites (byproducts of growth) that are toxic to animals and humans. Reproduction in fungi occurs through the production of spores. These spores can then reproduce without coming into contact with a different plant (asexual reproduction). The small size of the spores aid in their dispersal. They can become airborne and move by the action of winds and travel from field to field. They also can become attached to insects and birds which then transport them from plant to plant. Transport can also occur by use of contaminated trucks and equipment. Fungal infection from spores can occur at any of the various stages of crop production. It can begin in the fields, in or on the crop itself. It can infect healthy products during transportation and storage by coming into contact with contaminated equipment or grain products. The spores can lay dormant (inactive) in the soil or accumulate on equipment or in storage facilities for months or sometimes years until the proper conditions for growth occur and infect generation after generation. There are many varied environmental conditions that need to be in place before the spores will germinate or begin to grow. Generally relative humidity over 70% and temperatures over 30C (86F) for extended periods (several days to a week) are generally needed. Stress to the plants such as periods of drought, flooding, or insect infestation are also common factors in the fungus growth cycle. High moisture content of the crops (20% or higher in corn), as at the optimal times of growth and harvest, give the sp