Pyrenophora seminiperda | |
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Pyrenophora seminiperda spores | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Dothideomycetes |
Order: | Pleosporales |
Family: | Pleosporaceae |
Genus: | Pyrenophora |
Species: | P. seminiperda |
Binomial name | |
Pyrenophora seminiperda (Brittleb. & D.B. Adam) Shoemaker, (1966) | |
Pyrenophora seminiperda is a minor plant pathogen that causes leaf spots on many grasses. [1] It is an important generalist grass seed pathogen [2] which causes visible cylindrical masses of black fungal hyphae (stromata) to grow from infected seeds. Hence the common name "black fingers of death" [3]
It has been hypothesized that the fungus arrived in North America with invasive grasses from Eurasia. [4] BFOD has been suggested as a method of biocontrol of the invasive cheatgrass, one of the most important invasive species in the USA. [3] [5] Various secondary metabolites of the fungus, including Cytochalasin B, Pyrenophoric Acid-B, and Spirostaphylotrichin W, appears to be responsible for the seed killing. [6] [7] [8]
Botrytis cinerea is a necrotrophic fungus that affects many plant species, although its most notable hosts may be wine grapes. In viticulture, it is commonly known as "botrytis bunch rot"; in horticulture, it is usually called "grey mould" or "gray mold".
Bromus tectorum, known as downy brome, drooping brome or cheatgrass, is a winter annual grass native to Europe, southwestern Asia, and northern Africa, but has become invasive in many other areas. It now is present in most of Europe, southern Russia, Japan, South Africa, Australia, New Zealand, Iceland, Greenland, North America and western Central Asia. In the eastern US B. tectorum is common along roadsides and as a crop weed, but usually does not dominate an ecosystem. It has become a dominant species in the Intermountain West and parts of Canada, and displays especially invasive behavior in the sagebrush steppe ecosystems where it has been listed as noxious weed. B. tectorum often enters the site in an area that has been disturbed, and then quickly expands into the surrounding area through its rapid growth and prolific seed production.
Aspergillus flavus is a saprotrophic and pathogenic fungus with a cosmopolitan distribution. It is best known for its colonization of cereal grains, legumes, and tree nuts. Postharvest rot typically develops during harvest, storage, and/or transit. Its specific name flavus derives from the Latin meaning yellow, a reference to the frequently observed colour of the spores. A. flavus infections can occur while hosts are still in the field (preharvest), but often show no symptoms (dormancy) until postharvest storage or transport. In addition to causing preharvest and postharvest infections, many strains produce significant quantities of toxic compounds known as mycotoxins, which, when consumed, are toxic to mammals. A. flavus is also an opportunistic human and animal pathogen, causing aspergillosis in immunocompromised individuals.
Bromus is a large genus of grasses, classified in its own tribe Bromeae. They are commonly known as bromes, brome grasses, cheat grasses or chess grasses. Estimates in the scientific literature of the number of species have ranged from 100 to 400, but plant taxonomists currently recognize around 160–170 species.
An endophyte is an endosymbiont, often a bacterium or fungus, that lives within a plant for at least part of its life cycle without causing apparent disease. Endophytes are ubiquitous and have been found in all species of plants studied to date; however, most of the endophyte/plant relationships are not well understood. Some endophytes may enhance host growth, nutrient acquisition and improve the plant's ability to tolerate abiotic stresses, such as drought and decrease biotic stresses by enhancing plant resistance to insects, pathogens and herbivores. Although endophytic bacteria and fungi are frequently studied, endophytic archaea are increasingly being considered for their role in plant growth promotion as part of the core microbiome of a plant.
Claviceps purpurea is an ergot fungus that grows on the ears of rye and related cereal and forage plants. Consumption of grains or seeds contaminated with the survival structure of this fungus, the ergot sclerotium, can cause ergotism in humans and other mammals. C. purpurea most commonly affects outcrossing species such as rye, as well as triticale, wheat and barley. It affects oats only rarely.
Alternaria is a genus of Deuteromycetes fungi. All species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma. They are present in the human mycobiome and readily cause opportunistic infections in immunocompromised people such as AIDS patients.
The fungus Cochliobolus sativus is the teleomorph of Bipolaris sorokiniana (anamorph) which is the causal agent of a wide variety of cereal diseases. The pathogen can infect and cause disease on roots, leaf and stem, and head tissue. C. sativus is extremely rare in nature and thus it is the asexual or anamorphic stage which causes infections. The two most common diseases caused by B. sorokiniana are spot blotch and common root rot, mainly on wheat and barley crops.
Epichloë is a genus of ascomycete fungi forming an endophytic symbiosis with grasses. Grass choke disease is a symptom in grasses induced by some Epichloë species, which form spore-bearing mats (stromata) on tillers and suppress the development of their host plant's inflorescence. For most of their life cycle however, Epichloë grow in the intercellular space of stems, leaves, inflorescences, and seeds of the grass plant without incurring symptoms of disease. In fact, they provide several benefits to their host, including the production of different herbivore-deterring alkaloids, increased stress resistance, and growth promotion.
Alternaria alternata is a fungus causing leaf spots, rots, and blights on many plant parts, and other diseases. It is an opportunistic pathogen on over 380 host species of plant.
Pyrenophora tritici-repentis (teleomorph) and Drechslera tritici-repentis (anamorph) is a necrotrophic plant pathogen of fungal origin, phylum Ascomycota. The pathogen causes a disease originally named yellow spot but now commonly called tan spot, yellow leaf spot, yellow leaf blotch or helminthosporiosis. At least eight races of the pathogen are known to occur based on their virulence on a wheat differential set.
Sclerotinia sclerotiorum is a plant pathogenic fungus and can cause a disease called white mold if conditions are conducive. S. sclerotiorum can also be known as cottony rot, watery soft rot, stem rot, drop, crown rot and blossom blight. A key characteristic of this pathogen is its ability to produce black resting structures known as sclerotia and white fuzzy growths of mycelium on the plant it infects. These sclerotia give rise to a fruiting body in the spring that produces spores in a sac which is why fungi in this class are called sac fungi (Ascomycota). This pathogen can occur on many continents and has a wide host range of plants. When S. sclerotiorum is onset in the field by favorable environmental conditions, losses can be great and control measures should be considered.
Bipolaris cactivora is a plant pathogen causing cactus stem rot and pitaya fruit rot.
Raymond J. St. Leger is an American mycologist, entomologist, molecular biologist and biotechnologist who currently holds the rank of Distinguished University Professor in the Department of Entomology at the University of Maryland, College Park.
Striga hermonthica, commonly known as purple witchweed or giant witchweed, is a hemiparasitic plant that belongs to the family Orobanchaceae. It is devastating to major crops such as sorghum and rice. In sub-Saharan Africa, apart from sorghum and rice, it also infests maize, pearl millet, and sugar cane.
Plant use of endophytic fungi in defense occurs when endophytic fungi, which live symbiotically with the majority of plants by entering their cells, are utilized as an indirect defense against herbivores. In exchange for carbohydrate energy resources, the fungus provides benefits to the plant which can include increased water or nutrient uptake and protection from phytophagous insects, birds or mammals. Once associated, the fungi alter nutrient content of the plant and enhance or begin production of secondary metabolites. The change in chemical composition acts to deter herbivory by insects, grazing by ungulates and/or oviposition by adult insects. Endophyte-mediated defense can also be effective against pathogens and non-herbivory damage.
Morchella snyderi is a species of fungus in the family Morchellaceae. Described as new to science in 2012, it occurs in the montane forests of western North America, including California, Idaho, Montana, Oregon and Washington. It produces fruit bodies up to 14 cm (5.5 in) tall with ridged and pitted conical caps, and stipes that become pitted in maturity. The color of the morel is yellow to tan when young, but the cap ridges become brown to black in maturity or when dried.
Morchella sextelata is a species of ascomycete fungus in the family Morchellaceae. Described as new to science in 2012, it is found in North America. It has also been found in China, although it is not known if this is a result of an accidental introduction or natural dispersion. The fruit bodies have a roughly conical cap up to 7.5 cm (3 in) tall and 5 cm (2 in) wide, with a surface of mostly vertically arranged pits. The cap is initially yellowish to brownish, but it darkens to become almost black in maturity. The stipe is white and hollow, measuring 2–5 cm (0.8–2.0 in) high by 1–2.2 cm (0.4–0.9 in) wide.
Epicoccum nigrum is a species of fungus in the phylum Ascomycota. A plant pathogen and endophyte, it is a widespread fungus which produces coloured pigments that can be used as antifungal agents against other pathogenic fungi. The fluorescent stain epicocconone is extracted from it.
Radicinin is a phytotoxin with the molecular formula C12H12O5. Radicinin is produced by the fungal plant pathogen Alternaria radicina and other Alternaria species.
Dr. Erin Mordecai discusses BFOD and Cheatgrass during a seminar at the Department of Ecology and Evolutionary Biology at University of Michigan, Feb. 16, 2017