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Orchid Mycorrhiza
Orchid mycorrhizae are endomycorrhizal fungi which develop symbiotic relationships with the roots and seeds of plants of the family Orchidaceae. Nearly all orchids are myco-heterotrophic at some point in their life cycle. Orchid mycorrhizae are critically important during orchid germination, as an orchid seed has virtually no energy reserve and obtains its carbon from the fungal symbiont. The symbiosis starts with a structure called a protocorm''.'' During the symbiosis, the fungus develops structures called pelotons within the root cortex of the orchid. Many adult orchids retain their fungal symbionts throughout their life, although the benefits to the adult photosynthetic orchid and the fungus remain largely unexplained. Seed germination Orchids have several life stages. The first stage is the non-germinated orchid seed, the next stage is the protocorm, and the following stage is the adult orchid. Orchid seeds are very small (0.35mm to 1.50mm long), spindle-shaped, and h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endomycorrhiza
A mycorrhiza (; , mycorrhiza, or mycorrhizas) is a symbiosis, symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, the plant root system and its surroundings. Mycorrhizae play important roles in plant nutrition, soil life, soil biology, and soil chemistry. In a mycorrhizal association, the fungus colonizes the host plant's root tissues, either intracellularly as in arbuscular mycorrhizal fungi, or extracellularly as in #Ectomycorrhiza, ectomycorrhizal fungi. The association is normally Mutualism (biology), mutualistic. In particular species, or in particular circumstances, mycorrhizae may have a Parasitism, parasitic association with host plants. Definition A mycorrhiza is a symbiotic association between a green plant and a fungus. The plant makes organic molecules by photosynthesis and supplies them to the fungus in the form of sugars or lipids, while the fungus supplies the plant with water and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungal Symbiosis
A mycorrhiza (; , mycorrhiza, or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, the plant root system and its surroundings. Mycorrhizae play important roles in plant nutrition, soil biology, and soil chemistry. In a mycorrhizal association, the fungus colonizes the host plant's root tissues, either intracellularly as in arbuscular mycorrhizal fungi, or extracellularly as in ectomycorrhizal fungi. The association is normally mutualistic. In particular species, or in particular circumstances, mycorrhizae may have a parasitic association with host plants. Definition A mycorrhiza is a symbiotic association between a green plant and a fungus. The plant makes organic molecules by photosynthesis and supplies them to the fungus in the form of sugars or lipids, while the fungus supplies the plant with water and mineral nutrients, such as phosphorus, taken from the soil. Mycorrhizas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russula
''Russula'' is a very large genus composed of around 750 worldwide species of fungi. The genus was described by Christian Hendrik Persoon in 1796. The mushrooms are fairly large, and brightly colored – making them one of the most recognizable genera among mycologists and mushroom collectors. Their distinguishing characteristics include usually brightly coloured caps, a white to dark yellow spore print, brittle, attached gills, an absence of latex, and absence of partial veil or volva tissue on the stem. Microscopically, the genus is characterised by the amyloid ornamented spores and flesh (trama) composed of spherocysts. Members of the related genus ''Lactarius'' have similar characteristics but emit a milky latex when their gills are broken. The ectomycorrhizal mushrooms are typically common. Although some species are toxic, a number of others are edible. Taxonomy Christian Hendrik Persoon first circumscribed the genus ''Russula'' in his 1796 work ''Observationes Mycologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tulasnella
''Tulasnella'' is a genus of effused (patch-forming) fungi in the order Cantharellales. Basidiocarps (fruit bodies), when visible, are typically smooth, ceraceous (waxy) to subgelatinous, frequently lilaceous to violet-grey, and formed on the underside of fallen branches and logs. They are microscopically distinct in having basidia with grossly swollen sterigmata (or epibasidia) on which basidiospores are formed. One atypical species, '' Tulasnella aurantiaca'', produces orange to red, gelatinous, pustular anamorphs on wood. Some species form facultative mycorrhizas with orchids and liverworts. Around 80 species of ''Tulasnella'' are known worldwide. Taxonomy History ''Tulasnella'' was originally circumscribed by German mycologist Joseph Schröter in 1888, partly based on an earlier illustration by Charles Tulasne, after whom the new genus was named. Schröter believed the unusual basidia sufficiently distinct to warrant the creation of a new genus which he considered intermedi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sebacina
''Sebacina'' is a genus of fungi in the family Sebacinaceae. Its species are mycorrhizal, forming a range of associations with trees and other plants. Basidiocarps (fruit bodies) are produced on soil and litter, sometimes partly encrusting stems of living plants. The fruit bodies are cartilaginous to rubbery-gelatinous and variously effused (corticioid) to coral-shaped (clavarioid). The genus has a cosmopolitan distribution. Taxonomy History The genus was first published in 1871 by Louis and Charles Tulasne who had discovered that two species (''Sebacina incrustans'' and ''Sebacina epigaea'') previously referred to '' Corticium'' or '' Thelephora'' possessed septate basidia, similar to those found in the genus '' Tremella''. Although it was unusual at that time to separate fungal genera on purely microscopic characters, ''Sebacina'' was erected for effused, ''Corticium''-like fungi with tremelloid basidia. Subsequent authors added many additional species of corticioid fungi wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizoctonia
''Rhizoctonia'' is a genus of fungi in the family Ceratobasidiaceae. Species form thin, effused, corticioid basidiocarps (fruit bodies), but are most frequently found in their sterile, anamorph state. ''Rhizoctonia'' species are saprotrophic, but some are also facultative plant pathogens, causing commercially important crop diseases. Some are also endomycorrhizal associates of orchids. The genus name was formerly used to accommodate many superficially similar, but unrelated fungi. Taxonomy History Anamorphs ''Rhizoctonia'' was introduced in 1815 by French mycologist Augustin Pyramus de Candolle for anamorphic plant pathogenic fungi that produce both hyphae and sclerotia. The name is derived from Ancient Greek, ῥίζα (''rhiza'', "root") + κτόνος (''ktonos'', "murder"), and de Candolle's original species, ''Rhizoctonia crocorum'' ( teleomorph '' Helicobasidium purpureum''), is the causal agent of violet root rot of carrots and other root vegetables. Subsequent a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratobasidium
''Ceratobasidium'' is a genus of fungi in the order Cantharellales. Basidiocarps (fruit bodies) are effused and the genus is sometimes grouped among the corticioid fungi, though species also retain features of the heterobasidiomycetes. Anamorphic forms were formerly referred to the genus ''Ceratorhiza'', but this is now considered a synonym of '' Rhizoctonia''. ''Ceratobasidium'' species, excluding the type, are also now considered synonymous with ''Rhizoctonia'' and some species have been transferred to the latter genus. Species are saprotrophic, but several are also facultative plant pathogens, causing a number of commercially important crop diseases. Some are also endomycorrhizal associates of orchids. Taxonomy The name ''Ceratobasidium'' was introduced in 1935 by American mycologist D.P. Rogers to accommodate species of the old form genus '' Corticium'' that showed affinities with the heterobasidiomycetes. These affinities were the possession of large sterigmata ("cera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basidiomycetes
Basidiomycota () is one of two large division (mycology), divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basidiomycota includes these groups: agarics, puffballs, Phallaceae, stinkhorns, Bracket fungus, bracket fungi, other polypores, Jelly fungus, jelly fungi, boletes, Cantharellus, chanterelles, Geastraceae, earth stars, Smut (fungus), smuts, Common bunt, bunts, Rust (fungus), rusts, Sporobolomyces, mirror yeasts, and ''Cryptococcus (fungus), Cryptococcus'', the human pathogenic yeast. Basidiomycota are filamentous fungi composed of hyphae (except for Yeast, basidiomycota-yeast) and reproduce sexually via the formation of specialized club-shaped end Cell (biology), cells called Basidium, basidia that normally bear external Meiosis, meiospores (usually four). These specialized spores are called basidiospores. However, some Bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orchid Mycorrhizal Fungus From Zambia On Agar Plate, Kew Gardens
Orchids are plants that belong to the family (biology), family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Orchids are cosmopolitan distribution, cosmopolitan plants that are found in almost every habitat (ecology), habitat on Earth except glaciers. The world's species richness, richest diversity of orchid genera and species is in the tropics. Orchidaceae is one of the two largest families of flowering plants, the other being the Asteraceae. It contains about 28,000 currently accepted species in 702 genera. The Orchidaceae family encompasses about 6–11% of all species of seed plants. The largest genera are ''Bulbophyllum'' (2,000 species), ''Epidendrum'' (1,500 species), ''Dendrobium'' (1,400 species) and ''Pleurothallis'' (1,000 species). It also includes ''Vanilla (genus), Vanilla'' (the genus of the Vanilla planifolia, vanilla plant), the type genus ''Orchis'', and many commonly cultivated plants s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epiphyte
An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phorophytes. Epiphytes take part in nutrient cycles and add to both the diversity and biomass of the ecosystem in which they occur, like any other organism. In some cases, a rainforest tree's epiphytes may total "several tonnes" (several long tons). They are an important source of food for many species. Typically, the older parts of a plant will have more epiphytes growing on them. Epiphytes differ from parasites in that they grow on other plants for physical support and do not necessarily affect the host negatively. An organism that grows on another organism that is not a plant may be called an epibiont. Epiphytes are usually found in the temperate zone (e.g., many mosses, liverworts, lichens, and algae) or in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lewis Knudson
Lewis Knudson (1884–1958) was an American botanist who dedicated most of his professional life to the study of the biology, reproduction and propagation of orchids. He obtained his Bachelor of Science and Arts degree at the University of Missouri in 1908 and came to Cornell University as an assistant in plant physiology. Here he earned his doctorate, was appointed assistant professor of plant physiology in 1911 and was made acting head of that department in 1912. In 1916, his department became incorporated into the department of botany and he became a professor of botany. In 1941 he was named the head of this department. He retired in 1952. Orchid seeds are extremely small and hold scant sustenance. For this reason, in nature they need to associate with a fungus during germination which provides them nutrients required for growth and development. This process is known as "symbiotic germination" and until 1922 was the only known method of seed based propagation of orchids. That ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noël Bernard (botanist)
Noël Pierre Joseph León Bernard (13 March 1874 in the 17th arrondissement of Paris – 16 January 1911 in Saint-Benoît, Vienne) was a French botanist, known as the famous discoverer of the symbiotic germination of orchid seeds. He also discovered Phytoalexins which are antimicrobial and often antioxidative substances synthesized ''de novo'' by plants that accumulate rapidly at areas of pathogen infection. Early life and education His father was François Bernard, a wealthy cloth and textiles distributor based in Béziers in southern France, who moved to Paris and died when Bernard was 5 years old. His mother was Marie-Marguerite, who worked as a milliner to fund his studies. Bernard was considered an outstanding student while attending the Lycée Charlemagne later Lycée Condorcet senior high schools, both located in Paris, in preparation for entry to the Grandes Ecoles, of which he eventually gained entry to the grand school École Normale Supérieure. Bernard eventually ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
