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Phycomycetes
Phycomycetes is an obsolete polyphyletic taxon for certain fungi with aseptate hyphae. It is used in the Engler system. Asexual reproduction takes place by zoospores(motile) or by Aplanospores(non-motile).These spores are endogenously produced in sporangium.A zygospore is formed by fusion of two gametes.These gametes are similar in morphology sogamousor dissimilar nisogamous or oogamous The class Phycomycetes has been abolished and in its place exists Zygomycetes, Chytridiomycetes, Plasmodiophoromycetes, Hyphochytridiomycetes, Trichomycetes (including Harpellales, Asellariales, Eccrinales and Amoebidiales) and Oomycetes. Still, "Phycomycetes" can be used to refer to all the above-mentioned classes as a whole. The members of this group are found in aquatic habitats and on decaying wood in moist and damp places or as obligate parasites on plants. The mycelium is aseptate and coenocytic. Asexual reproduction by zoospore or by aplanospore. A zygospore is formed by the fusio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmodiophoromycetes
The plasmodiophores (also known as plasmophorids or plasmodiophorids) are a group of obligate endoparasitic protists belonging to the subphylum Endomyxa in Cercozoa. Taxonomically, they are united under a single family Plasmodiophoridae, order Plasmodiophorida, sister to the phagomyxids. Ecology and pathology Plasmodiophores are pathogenic for a wide range of organisms, but mainly green plants. The more commonly recognized are agents of plant diseases such as clubroot, powdery scab and crook root of watercress, or vectors for viruses that infect beets, peanut, monocots and potatoes, such as the potato mop-top virus or the beet necrotic yellow vein virus. Taxonomy History The plasmodiophores have historically been regarded as Fungi. The first description of plasmodiophores as a taxonomic group was in 1885 by Zopf, who united two genera '' Plasmodiophora'' and '' Tetramyxa'' in a common family “Plasmodiophoreæ”, inside the group “Monadineæ”, as part of the division M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasitic Fungi
A fungus ( : fungi 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 a kingdom, separately from the other eukaryotic kingdoms, which by one traditional classification include Plantae, Animalia, 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 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 fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mastigomycotina
Mastigomycotina is a former polyphyletic taxonomic grouping, a subdivision, of fungi, similar to Phycomycetes, and that included the zoosporic classes Chytridiomycetes, Hyphochytriomycetes, Plasmodiophoromycetes and Oomycetes. General features of Mastigomycotina:Wong, G. J.: Classification of Fungi'. URL last accessed 2007-04-03. * They produce flagellated cells during their lifetime. * May bear rhizoids. * Mostly, filamentous and having coenocytic mycelium. * Show centric nuclear division. * Perfect state of spores is typically oospore An oospore is a thick-walled sexual spore that develops from a fertilized oosphere in some algae, fungi, and oomycetes. They are believed to have evolved either through the fusion of two species or the chemically-induced stimulation of mycelia ...s. See also * Fungus-like organisms References Obsolete fungus taxa {{fungus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungus
A fungus ( : fungi 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 a kingdom, separately from the other eukaryotic kingdoms, which by one traditional classification include Plantae, Animalia, 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 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'' (''tru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engler System
One of the prime systems of plant taxonomy, the Engler system was devised by Adolf Engler (1844–1930), and is featured in two major taxonomic texts he authored or co-authored. His influence is reflected in the use of the terms "Engler School" and "Engler Era". Engler's starting point was that of Eichler who had been the first to use phylogenetic principles, although Engler himself did not think that he was. Engler's works His modified Eichler schema first appeared in 1886 in his ''Guide to Breslau Botanic Garden'' (of which he was the director) and was expanded in his '' Syllabus der Pflanzenfamilien'' in 1892. This reflected the new post-Darwinian perspective. Engler's ''Syllabus'' first appeared in 1892 with the title ''Syllabus der Vorlesungen über specielle und medicinisch-pharmaceutische Botanik''. Many subsequent editions have appeared since, and it was continued after Engler's death in 1930. The most recent edition was the 13th in 2009. The other major work was ''Die ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coenocytic
A coenocyte () is a multinucleate cell which can result from multiple nuclear divisions without their accompanying cytokinesis, in contrast to a syncytium, which results from cellular aggregation followed by dissolution of the cell membranes inside the mass. The word syncytium in animal embryology is used to refer to the coenocytic blastoderm of invertebrates. A coenocytic colony is referred to as a coenobium (plural coenobia), and most coenobia are composed of a distinct number of cells, often as a multiple of two (4, 8, etc.). Research suggests that coenobium formation may be a defense against grazing in some species. Physiological examples Protists Diplomonads, like ''Giardia'', have two nuclei. Ciliates have cells that contain two nuclei: a macronucleus and a micronucleus. The schizont of apicomplexan parasites is a form of a coenocyte (i.e. a plasmodium in the general sense) as well as the plasmodia of microsporidian (Fungi) and myxosporidian (Metazoa) parasites. The tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soham
Soham ( ) is a town and civil parish in the district of East Cambridgeshire, in Cambridgeshire, England, just off the A142 between Ely and Newmarket. Its population was 10,860 at the 2011 census. History Archaeology The region between Devil's Dyke and the line between Littleport and Shippea Hill shows a remarkable amount of archaeological findings of the Stone Age, the Bronze Age and the Iron Age. A couple of hoards of bronze objects are found in the area of Soham, including one with swords and spearheads of the later Bronze Age as well as a gold torc, retrieved in 1938. A large Anglo-Saxon settlement was discovered on land between Brook Street and Fordham Road, next to Roman remains in the old Fisky's Hill area and former allotment site in 2013 and onwards. During the establishment of the Fordham Road cemetery, in the late 1800's, burial remains were also found with several high-status grave goods, including a girdle hanger, beads and Jewlery. These items are now house ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saprolegnia
''Saprolegnia'' is a genus of water moulds often called cotton moulds because of the characteristic white or grey fibrous patches they form. Current taxonomy puts ''Saprolegnia'' as a genus of the heterokonts in the order Saprolegniales. Habits ''Saprolegnia'', like most oomycetes, is both a saprotroph and necrotroph. Typically feeding on waste from fish or other dead cells, they will also take advantage of creatures that have been injured. An infection is known as oomycosis. ''Saprolegnia'' is tolerant to a wide range of temperature, , but is more prevalent in lower temperatures. While it is found most frequently in freshwater, it will also tolerate brackish water and even moist soil. ''Saprolegnia'' filaments (hyphae) are long with rounded ends, containing the zoospores. Saprolegnia generally travels in colonies consisting of one or more species. They first form a mass of individual hyphae. When the mass of hyphae grows large enough in size to be seen without use of a micro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albugo
''Albugo'' is a genus of plant-parasitic oomycetes. Those are not true fungi ( Eumycota), although many discussions of this organism still treat it as a fungus. The taxonomy of this genus is incomplete, but several species are plant pathogens. ''Albugo'' is one of three genera currently described in the family Albuginaceae, the taxonomy of many species is still in flux. This organism causes white rust or white blister diseases in above-ground plant tissues. While these organisms affect many types of plants, the destructive aspect of infection is limited to a few agricultural crops, including: beets (garden and sugar), Brussels sprouts, cabbages, Chinese cabbage, cauliflower, collards, garden cress, kale, lettuce, mustards, parsnip, radish, horseradish, rapeseed, salsify (black or white), spinach, sweet potatoes, turnips, watercress, and perhaps water-spinach. Summary White rust plant diseases caused by ''Albugo'' fungal-like pathogens should not be confused with white pine bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizopus
''Rhizopus'' is a genus of common saprophytic fungi on plants and specialized parasites on animals. They are found in a wide variety of organic substances, including "mature fruits and vegetables", jellies, syrups, leather, bread, peanuts, and tobacco. They are multicellular. Some ''Rhizopus'' species are opportunistic human pathogens that often cause fatal disease called mucormycosis. This widespread genus includes at least eight species. ''Rhizopus'' species grow as filamentous, branching hyphae that generally lack cross-walls (i.e., they are coenocytic). They reproduce by forming asexual and sexual spores. In asexual reproduction, sporangiospores are produced inside a spherical structure, the sporangium. Sporangia are supported by a large apophysate columella atop a long stalk, the sporangiophore. Sporangiophores arise among distinctive, root-like rhizoids. In sexual reproduction, a dark zygospore is produced at the point where two compatible mycelia fuse. Upon germinati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucor
''Mucor'' is a microbial genus of approximately 40 species of molds in the family Mucoraceae. Species are commonly found in soil, digestive systems, plant surfaces, some cheeses like Tomme de Savoie, rotten vegetable matter and iron oxide residue in the biosorption process. Description Colonies of this fungal genus are typically white to beige or grey and fast-growing. Colonies on culture medium may grow to several centimeters in height. Older colonies become grey to brown in color due to the development of spores. The species 'Mucor' belongs to the microbial kingdom: Fungi. ''Mucor'' spores or sporangiospores can be simple or branched and form apical, globular sporangia that are supported and elevated by a column-shaped columella. ''Mucor'' species can be differentiated from molds of the genera '' Absidia'', ''Rhizomucor'', and '' Rhizopus'' by the shape and insertion of the columella, and the lack of stolons and rhizoids. Some ''Mucor'' species produce chlamydospores ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamete
A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual that produces the larger type of gamete—called an ovum— and a male produces the smaller type—called a sperm. Sperm cells or spermatozoa are small and motile due to the flagellum, a tail-shaped structure that allows the cell to propel and move. In contrast, each egg cell or ovum is relatively large and non-motile. In short a gamete is an egg cell (female gamete) or a sperm (male gamete). In animals, ova mature in the ovaries of females and sperm develop in the testes of males. During fertilization, a spermatozoon and ovum unite to form a new diploid organism. Gametes carry half the genetic information o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
