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Rhytisma Acerinum
''Rhytisma acerinum'' is a plant pathogen that commonly affects sycamores and maples in late summer and autumn, causing tar spot. Tar spot does not usually have an adverse effect on the trees' long-term health. ''R. acerinum'' is an Ascomycete fungus that locally infects the leaves of trees and is a biotrophic parasite.Roland W.S. Weber and John Webster (2002). Teaching techniques for mycology: 18. ''Rhytisma acerinum'', cause of tar-spot disease of sycamore leaves. Mycologist, 16, pp 120-123 The disease is cosmetic and is therefore usually controlled only with sanitation methods.Hudelson, Brian. Wisconsin Horticulture UW-Extension Cooperative Extension. UW-Madison Plant Pathology, April 25, 2004. Web. Oct. 22, 2011. Symptoms and signs In late spring, chlorotic spots appear on tree leaves. These develop into brown-black lesions, retaining the yellow border. The lesions continue to grow, and by the end of summer form leaf spots that look like tar. The spot can grow up to in diame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acer Platanoides
''Acer platanoides'', commonly known as the Norway maple, is a species of maple native to eastern and central Europe and western Asia, from Spain east to Russia, north to southern Scandinavia and southeast to northern Iran. It was introduced to North America in the mid-1700s as a shade tree. It is a member of the family Sapindaceae. Description ''Acer platanoides'' is a deciduous tree, growing to tall with a trunk up to in diameter, and a broad, rounded crown. The bark is grey-brown and shallowly grooved. Unlike many other maples, mature trees do not tend to develop a shaggy bark. The shoots are green at first, soon becoming pale brown. The winter buds are shiny red-brown. The leaves are opposite, palmately lobed with five lobes, long and across; the lobes each bear one to three side teeth, and an otherwise smooth margin. The leaf petiole is long, and secretes a milky juice when broken. The autumn colour is usually yellow, occasionally orange-red. The flowers are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorosis
In botany, chlorosis is a condition in which leaves produce insufficient chlorophyll. As chlorophyll is responsible for the green color of leaves, chlorotic leaves are pale, yellow, or yellow-white. The affected plant has little or no ability to manufacture carbohydrates through photosynthesis and may die unless the cause of its chlorophyll insufficiency is treated and this may lead to a plant disease called rusts, although some chlorotic plants, such as the albino ''Arabidopsis thaliana'' mutant ''ppi2'', are viable if supplied with exogenous sucrose. The word ''chlorosis'' is derived from the Greek ''khloros'' meaning "greenish-yellow", "pale green", "pale", "pallid", or "fresh". In viticulture, the most common symptom of poor nutrition in grapevines is the yellowing of grape leaves caused by chlorosis and the subsequent loss of chlorophyll. This is often seen in vineyard soils that are high in limestone such as the Italian wine region of Barolo in the Piedmont (wine), Piedmont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leotiomycetes
The Leotiomycetes are a class of ascomycete fungi. Many of them cause serious plant diseases. Systematics The class Leotiomycetes contains numerous species with an anamorph placed within the '' fungi imperfecti'' (deuteromycota), that have only recently found their place in the phylogenetic system. The older classifications placed Leotiomycetes into the Discomycetes clade ( inoperculate Discomycetes). Molecular studies have recently shed some new light to the still obscure systematics. Most scholars consider Leotiomycetes a sister taxon to Sordariomycetes in the phylogenetic tree of Pezizomycotina. Its division into subclasses have received strong support by the molecular data, but the overall monophyly of Leotiomycetes is dubious. The order Lichinodiales and family '' Lichinodiaceae'', newly circumscribed in 2019 to contain the genus cyanolichen genus '' Lichinodium'', is the first known group of lichen-forming fungi in the Leotiomycetes. Family ''Lichinodiaceae'' was then ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungal Tree Pathogens And Diseases
A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as one of the traditional eukaryotic kingdoms, along with Animalia, Plantae, and either Protista or Protozoa and Chromista. A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of motility, mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the ''Eumycota'' (''true fungi'' or ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllachora Maydis
''Phyllachora maydis'' is a plant pathogen causing ascomycete diseases in maize/corn, and is more commonly referred to as ''tar spot''. Identified by the distinctive development of stroma, this pathogen in itself is of little economic importance in the production of corn. However, the accompanying fungal infection of ''Monographella maydis,'' identified by "fish-eye" lesions, was claimed to cause significant foliar damage and subsequently yield reduction. there is insufficient information about this pathogen and its management. Symptoms and signs This pathogen is an obligate parasite solely of the species ''Zea mays''. The first symptoms are yellowing spots on both upper and lower leaf surfaces. Within the spot develops the characteristic black stromata over the ascomata, along with chlorosis of surrounding tissue. The chlorotic rings may be elliptical, circular, or may conjoin to form striping up to long. Some of the chlorotic tissue around the ascomata may become necrotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equine Atypical Myopathy
Equine atypical myopathy, also known as atypical myoglobinuria, or EAM is a fatal disease of horses (equidae) characterized by acute rhabdomyolysis. It is caused by the ingestion of the seeds or young shoots of sycamore tree. EAM has a high fatality rate. Cause Atypical myopathy is a commonly fatal form of equine rhabdomyolysis caused by the toxin Hypoglycin A (HGA). HGA is a naturally-occurring amino acid contained by trees and shrubs of Acer genus. Horses can become poisoned by eating the seeds or seedlings of Acer pseudoplatanus (called Sycamore in the UK or more widely Sycamore Maple) or Acer negundo (Box Elder). The amount of HGA in sycamore seeds may vary. The toxin affects the functioning of horse’s muscle cells by slowing down or stopping the energy production. Even if atypical myopathy is not contagious it can affect either to individual horse or several horses in the same stock. Some horses may be more resistant to the toxin than others due to genetic differences and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christiaan Hendrik Persoon
Christiaan Hendrik Persoon (31 December 1761 – 16 November 1836) was a Cape Colony mycologist who is recognized as one of the founders of mycology, mycological Taxonomy (biology), taxonomy. Early life Persoon was born in Cape Colony at the Cape of Good Hope, the third child of an immigrant Pomeranian father, Christiaan Daniel Persoon, and Netherlands, Dutch mother, Wilhelmina Elizabeth Groenwald. His mother died soon after he was born. In 1775, at the age of thirteen, he was sent to Europe for his education. His father died a year later in 1776. Education Initially a student of theology at University of Halle-Wittenberg, Halle, Persoon switched his studies to medicine, which he pursued in Leiden and then Göttingen. He received a doctorate from the German National Academy of Sciences Leopoldina, Deutsche Akademie der Naturforscher in Erlangen 1799. Later years He moved to Paris by 1803, where he spent the rest of his life, renting the upper floor of a house in a poor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur Dioxide
Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a colorless gas with a pungent smell that is responsible for the odor of burnt matches. It is released naturally by volcanic activity and is produced as a by-product of metals refining and the burning of Sour gas, sulfur-Sour crude oil, bearing fossil fuels. Sulfur dioxide is somewhat toxic to humans, although only when inhaled in relatively large quantities for a period of several minutes or more. It was known to medieval alchemy, alchemists as "volatile spirit of sulfur". Structure and bonding SO2 is a bent molecule with ''C''2v Point groups in three dimensions, symmetry point group. A valence bond theory approach considering just ''s'' and ''p'' orbitals would describe the bonding in terms of resonance (chemistry), resonance between two resonance structures. The sulfur–oxygen bond has a bond order of 1.5. There is support f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conidia
A conidium ( ; : conidia), sometimes termed an asexual chlamydospore or chlamydoconidium (: chlamydoconidia), is an asexual, non- motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the way they are generated through the cellular process of mitosis. They are produced exogenously. The two new haploid cells are genetically identical to the haploid parent, and can develop into new organisms if conditions are favorable, and serve in biological dispersal. Asexual reproduction in ascomycetes (the phylum Ascomycota) is by the formation of conidia, which are borne on specialized stalks called conidiophores. The morphology of these specialized conidiophores is often distinctive between species and, before the development of molecular techniques at the end of the 20th century, was widely used for identification of (''e.g.'' '' Metarhizium'') species. The terms microconidia and macroconidia are some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stromatolite
Stromatolites ( ) or stromatoliths () are layered Sedimentary rock, sedimentary formation of rocks, formations (microbialite) that are created mainly by Photosynthesis, photosynthetic microorganisms such as cyanobacteria, sulfate-reducing microorganism, sulfate-reducing bacteria, and Pseudomonadota (formerly proteobacteria). These microorganisms produce adhesive compounds that cementation (geology), cement sand and other rocky materials to form mineral "microbial mats". In turn, these mats build up layer by layer, growing gradually over time. This process generates the characteristic Lamination (geology), lamination of stromatolites, a feature that is hard to interpret, in terms of its temporal and environmental significance. Different styles of stromatolite lamination have been described, which can be studied through microscopic and mathematical methods. A stromatolite may grow to a meter or more. Fossilized stromatolites provide important records of some of the most ancient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conidiophores
A conidium ( ; : conidia), sometimes termed an asexual chlamydospore or chlamydoconidium (: chlamydoconidia), is an asexual, non- motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the way they are generated through the cellular process of mitosis. They are produced exogenously. The two new haploid cells are genetically identical to the haploid parent, and can develop into new organisms if conditions are favorable, and serve in biological dispersal. Asexual reproduction in ascomycetes (the phylum Ascomycota) is by the formation of conidia, which are borne on specialized stalks called conidiophores. The morphology of these specialized conidiophores is often distinctive between species and, before the development of molecular techniques at the end of the 20th century, was widely used for identification of (''e.g.'' '' Metarhizium'') species. The terms microconidia and macroconidia are sometime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anamorph
In mycology, the terms teleomorph, anamorph, and holomorph apply to portions of the life cycles of fungi in the phyla Ascomycota and Basidiomycota: *Teleomorph: the sexual reproductive stage (morph), typically a fruiting body. *Anamorph: an asexual reproductive stage (morph), often mold-like. When a single fungus produces multiple morphologically distinct anamorphs, these are called synanamorphs. *Holomorph: the whole fungus, including anamorphs and teleomorph. The terms were introduced in 1981 to simplify the discussion of the procedures of the existing dual-naming system, which (1) permitted anamorphs to have their separate names but (2) treated teleomorphic names as having precedence for being used as the holomorphic name. The ''Melbourne Code'' removes the provisions and allows all names to compete on equal footing for priority as the correct name of a fungus, and hence does not use the term ''holomorph'' any more. Dual naming of fungi Fungi are classified primarily based o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
