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Southern Corn Leaf Blight
Southern corn leaf blight (SCLB) is a fungal disease of maize caused by the plant pathogen '' Bipolaris maydis'' (also known as '' Cochliobolus heterostrophus'' in its teleomorph state). The fungus is an Ascomycete and can use conidia or ascospores to infect. There are three races of ''B. maydis'': Race O, Race C, and Race T; SCLB symptoms vary depending on the infectious pathogen's race. Race T is infectious to corn plants with the Texas male sterile cytoplasm (cms-T cytoplasm maize) and this vulnerability was the cause of the United States SCLB epidemic of 1969-19701 Ullstrup, A. J., ''Annual Review of Phytopathology'' 10 (1), 37 (1972). For this reason, Race T is of particular interest. While SCLB thrives in warm, damp climates, the disease can be found in many of the world's maize-growing areas. Typical management practices include breeding for host resistance, cultural controls and fungicide use. Hosts The primary host for Southern corn leaf blight is ''Zea mays'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maize
Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The leafy stalk of the plant produces pollen inflorescences (or "tassels") and separate ovuliferous inflorescences called ears that when fertilized yield kernels or seeds, which are fruits. The term ''maize'' is preferred in formal, scientific, and international usage as a common name because it refers specifically to this one grain, unlike ''corn'', which has a complex variety of meanings that vary by context and geographic region. Maize has become a staple food in many parts of the world, with the total production of maize surpassing that of wheat or rice. In addition to being consumed directly by humans (often in the form of masa), maize is also used for corn ethanol, animal feed and other maize products, such as corn starch and corn sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycotoxin
A mycotoxin (from the Greek μύκης , "fungus" and τοξίνη , "toxin") is a toxic secondary metabolite produced by organisms of kingdom Fungi and is capable of causing disease and death in both humans and other animals. The term 'mycotoxin' is usually reserved for the toxic chemical products produced by fungi that readily colonize crops. Examples of mycotoxins causing human and animal illness include aflatoxin, citrinin, fumonisins, ochratoxin A, patulin, trichothecenes, zearalenone, and ergot alkaloids such as ergotamine. One mold species may produce many different mycotoxins, and several species may produce the same mycotoxin. Production Most fungi are aerobic (use oxygen) and are found almost everywhere in extremely small quantities due to the diminute size of their spores. They consume organic matter wherever humidity and temperature are sufficient. Where conditions are right, fungi proliferate into colonies and mycotoxin levels become high. The reason for the pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crop Rotation
Crop rotation is the practice of growing a series of different types of crops in the same area across a sequence of growing seasons. It reduces reliance on one set of nutrients, pest and weed pressure, and the probability of developing resistant pests and weeds. Growing the same crop in the same place for many years in a row, known as monocropping, gradually depletes the soil of certain nutrients and selects for a highly competitive pest and weed community. Without balancing nutrient use and diversifying pest and weed communities, the productivity of monocultures is highly dependent on external inputs. Conversely, a well-designed crop rotation can reduce the need for synthetic fertilizers and herbicides by better using ecosystem services from a diverse set of crops. Additionally, crop rotations can improve soil structure and organic matter, which reduces erosion and increases farm system resilience. History Agriculturalists have long recognized that suitable rotations — ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Host (biology)
In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist ''guest'' (symbiont). The guest is typically provided with nourishment and shelter. Examples include animals playing host to parasitic worms (e.g. nematodes), cells harbouring pathogenic (disease-causing) viruses, a bean plant hosting mutualistic (helpful) nitrogen-fixing bacteria. More specifically in botany, a host plant supplies food resources to micropredators, which have an evolutionarily stable relationship with their hosts similar to ectoparasitism. The host range is the collection of hosts that an organism can use as a partner. Symbiosis Symbiosis spans a wide variety of possible relationships between organisms, differing in their permanence and their effects on the two parties. If one of the partners in an association is much larger than the other, it is generally known as the host. In parasitism, the parasite benefits a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascocarp
An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are most commonly bowl-shaped (apothecia) but may take on a spherical or flask-like form that has a pore opening to release spores (perithecia) or no opening (cleistothecia). Classification The ascocarp is classified according to its placement (in ways not fundamental to the basic taxonomy). It is called ''epigeous'' if it grows above ground, as with the morels, while underground ascocarps, such as truffles, are termed ''hypogeous''. The structure enclosing the hymenium is divided into the types described below (apothecium, cleistothecium, etc.) and this character ''is'' important for the taxonomic classification of the fungus. Apothecia can be relatively large and fleshy, whereas the others are microscopic—about the size of flecks of g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parenchyma
Parenchyma () is the bulk of functional substance in an animal organ or structure such as a tumour. In zoology it is the name for the tissue that fills the interior of flatworms. Etymology The term ''parenchyma'' is New Latin from the word παρέγχυμα ''parenchyma'' meaning 'visceral flesh', and from παρεγχεῖν ''parenchyma'' meaning 'to pour in' from παρα- ''para-'' 'beside' + ἐν ''en-'' 'in' + χεῖν ''chyma'' 'to pour'. Originally, Erasistratus and other anatomists used it to refer to certain human tissues. Later, it was also applied to plant tissues by Nehemiah Grew. Structure The parenchyma is the ''functional'' parts of an organ, or of a structure such as a tumour in the body. This is in contrast to the stroma, which refers to the ''structural'' tissue of organs or of structures, namely, the connective tissues. Brain The brain parenchyma refers to the functional tissue in the brain that is made up of the two types of brain cell, neurons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stoma
In botany, a stoma (from Greek ''στόμα'', "mouth", plural "stomata"), also called a stomate (plural "stomates"), is a pore found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange. The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the stomatal opening. The term is usually used collectively to refer to the entire stomatal complex, consisting of the paired guard cells and the pore itself, which is referred to as the stomatal aperture. Air, containing oxygen, which is used in respiration, and carbon dioxide, which is used in photosynthesis, passes through stomata by gaseous diffusion. Water vapour diffuses through the stomata into the atmosphere in a process called transpiration. Stomata are present in the sporophyte generation of all land plant groups except liverworts. In vascular plants the number, size and distribution of stomata varies wide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germ Tube
A germ tube is an outgrowth produced by spores of spore-releasing fungi during germination. The germ tube differentiates, grows, and develops by mitosis to create somatic hyphae.C.J. Alexopolous, Charles W. Mims, M. Blackwell, ''Introductory Mycology, 4th ed.'' (John Wiley and Sons, Hoboken NJ, 2004) A germ tube test is a diagnostic test in which a sample of fungal spores are suspended in animal serum and examined by microscopy for the detection of any germ tubes.Chapter IV. Germ Tube Test iYEAST IDENTIFICATION document at doctorfungus.org. Retrieved July 2011 It is particularly indicated for colonies of white or cream color on fungal culture, where a positive germ tube test is strongly indicative of ''Candida albicans''. See also * Oomycota Oomycota forms a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms, called oomycetes (). They are filamentous and heterotrophic, and can reproduce both sexually and asexually. Sexual reproduction of an oospor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inoculation
Inoculation is the act of implanting a pathogen or other microorganism. It may refer to methods of artificially inducing immunity against various infectious diseases, or it may be used to describe the spreading of disease, as in "self-inoculation," the spreading of disease from one part of the body to another, or even to the spreading of bacteria in a Petri dish for culturing purposes. The terms "inoculation", "vaccination", and "immunization" are often used synonymously, but there are some important differences among them. Inoculation is the act of implanting a disease inside a person or animal, vaccination is the act of implanting or giving someone a vaccine specifically, and immunization is what happens to the immune system as a result. Terminology Until the early 1800s inoculation referred only to variolation (from the Latin word ''variola'' = smallpox), the predecessor to the smallpox vaccine. The smallpox vaccine, introduced by Edward Jenner in 1796, was called cowpox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Corn Leaf Blight
Northern corn leaf blight (NCLB) or Turcicum leaf blight (TLB) is a foliar disease of corn (maize) caused by ''Exserohilum turcicum'', the anamorph of the ascomycete '' Setosphaeria turcica''. With its characteristic cigar-shaped lesions, this disease can cause significant yield loss in susceptible corn hybrids. Hosts and symptoms Lesions can eventually expand to a more oblong or “cigar” shape. They may also coalesce to form large areas of necrotic tissue. There are several host-specific forms of ''E. turcicum''. The most economically important host is corn, but other forms may infect sorghum, Johnson grass, or sudangrass. The most common diagnostic symptom of the disease on corn is cigar-shaped or elliptical necrotic gray-green lesions on the leaves that range from one to seven inches long. These lesions may first appear as narrow, tan streaks that run parallel to the leaf veins. Fully developed lesions typically have a sooty appearance during humid weather, as a result of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zea (plant)
''Zea'' is a genus of flowering plants in the grass family. The best-known species is ''Z. mays'' (variously called maize, corn, or Indian corn), one of the most important crops for human societies throughout much of the world. The four wild species are commonly known as teosintes and are native to Mesoamerica. Etymology ''Zea'' is derived from the Greek name () for another cereal grain (possibly spelt).Gledhill, David (2008). "The Names of Plants". Cambridge University Press. (hardback), (paperback). pp 411 Recognized species The five accepted species names in the genus are: '' Zea mays'' is further divided into four subspecies: ''Z. m. huehuetenangensis'', ''Z. m. mexicana'', '' Z. m. parviglumis'' (Balsas teosinte, the ancestor of maize), and ''Z. m. mays''. The first three subspecies are teosintes; the last is maize, or corn, the only domesticated taxon in the genus ''Zea''. The genus is divided into two sections: ''Luxuriantes'', with ''Z. diploperennis'', ''Z. l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorghum
''Sorghum'' () is a genus of about 25 species of flowering plants in the grass family (Poaceae). Some of these species are grown as cereals for human consumption and some in pastures for animals. One species is grown for grain, while many others are used as fodder plants, either cultivated in warm climates worldwide or naturalized in pasture lands. Taxonomy ''Sorghum'' is in the Poaceae (grass) subfamily Panicoideae and the tribe Andropogoneae (the same as maize, big bluestem and sugarcane). Species Accepted species recorded include: Distribution and habitat Seventeen of the 25 species are native to Australia, with the range of some extending to Africa, Asia, Mesoamerica, and certain islands in the Indian and Pacific Oceans. Toxicity In the early stages of the plants' growth, some species of sorghum can contain levels of hydrogen cyanide, hordenine, and nitrates, which are lethal to grazing animals. Plants stressed by drought or heat can also contain toxic level ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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