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Hemibiotroph
Hemibiotrophs are the spectrum of plant pathogens, including bacteria, oomycete and a group of plant pathogenic fungi that keep its host alive while establishing itself within the host tissue, taking up the nutrients with brief biotrophic-like phase. It then, in later stages of infection switches to a necrotrophic life-style, where it rampantly kills the host cells, deriving its nutrients from the dead tissues. This mode of interaction, in which initial biotrophy followed by a switch to necrotrophy, has been observed in the fungal model ''Magnaporthe oryzae'' (rice blast fungus) and other pathogens such as many ''Colletotrichum'' spp. (often called anthracnose diseases, e.g. ''Colletotrichum lindemuthianum''), Southern corn leaf blight (''Bipolaris maydis'') and, ''Zymoseptoria tritici'' (syn. ''Mycosphaerella graminicola'', leaf blotch of wheat). Collectively, they represent some of the most destructive plant parasites, causing huge economic losses, threatening global food secu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colletotrichum Lindemuthianum
''Colletotrichum lindemuthianum'' is a fungus which causes anthracnose, or black spot disease, of the common bean plant (''Phaseolus vulgaris''). It is considered a hemibiotrophic pathogen because it spends part of its infection cycle as a biotroph, living off of the host but not harming it, and the other part as a necrotroph, killing and obtaining nutrients from the host tissues. History The anthracnose of common bean was first identified in 1875 in the fruit and vegetable garden of the Agricultural Institute of Popplesdorf, Germany by Lindemuth.Leach, Julian Gilbert. 1922.The parasitism of colletotrichum lindemuthianum. University of Minnesota. Retrieved 30 March 2014 By 1878, Saccardo and Magnus had made many observations on the cause of the anthracnose disease, recording their results in ''Michelia'' I:129.Stoneman, Bertha. 1898. A comparative study of the development of some anthracnoses. Botanical Gazette 26 (2) (August, 1898). They concluded that it was caused by a fungus, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colletotrichum
''Colletotrichum'' (sexual stage: ''Glomerella'') is a genus of fungi that are symbionts to plants as endophytes (living within the plant) or phytopathogens. Many of the species in this genus are plant pathogens, but some species may have a mutualistic relationship with hosts. History The history of the ''Colletotrichum'' genus is a case study on the tension between the lumpers and splitters. While the genus ''Colletotrichum'' was first proposed in 1831, the exact definition of ''Colletotrichum'' and the species that belong in this genus has been in flux ever since. The biggest recent shift has been from a definition (of both the genus and the species within it) based on morphology to a definition based on a combination of morphology and molecular phylogenetics. The use of molecular phylogenetics has led to a huge increase in the number of recognized species in this genus, and the species are now organized into species complexes that usually have the name of their most widely k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moniliophthora Roreri
''Moniliophthora roreri'' is a basidiomycete fungus that causes frosty pod rot disease, one of the most serious problems for cacao (''Theobroma cacao''— the source of chocolate) production in Latin America. This disease and together with witches’ broom disease (caused by ''M. perniciosa'') and black pod rot (caused by ''Phytophthora'' sp.) constitute the cacao disease trilogy. It causes serious losses in southwestern parts of South America; spores are dry and powdery and are spread easily by water movement, wind, or movement of pods; disease spread is highest during periods of high rainfall. The fungus Taxonomy Originally, ''M. roreri'' was described as an anamorphic ascomycete, ''Monilia roreri'' Cif., due to the absence of a recognizable fruiting body or a sexual stage and other similarities to species of ''Monilia''. Later on it was noticed that the septa of the pathogen contained dolipores and septal pore caps, which are features of basidiomycete fungi. Consequently, '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pathogenic Fungus
Pathogenic fungi are fungi that cause disease in humans or other organisms. Approximately 300 fungi are known to be pathogenic to humans. Markedly more fungi are known to be pathogenic to plant life than those of the animal kingdom. The study of fungi pathogenic to humans is called "medical mycology". Although fungi are eukaryotic, many pathogenic fungi are microorganisms. The study of fungi and other organisms pathogenic to plants is called plant pathology. ''Candida'' ''Candida'' species cause infections in individuals with deficient immune systems. Th1-type cell-mediated immunity (CMI) is required for clearance of a fungal infection. ''Candida albicans'' is a kind of diploid yeast that commonly occurs among the human gut microflora. ''C. albicans'' is an opportunistic pathogen in humans. Abnormal over-growth of this fungus can occur, particularly in immunocompromised individuals. ''C. albicans'' has a parasexual cycle that appears to be stimulated by environmental stress. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haustorium
In botany and mycology, a haustorium (plural haustoria) is a rootlike structure that grows into or around another structure to absorb water or nutrients. For example, in mistletoe or members of the broomrape family, the structure penetrates the host's tissue and draws nutrients from it. In mycology, it refers to the appendage or portion of a parasitic fungus (the hyphal tip), which performs a similar function. Microscopic haustoria penetrate the host plant's cell wall and siphon nutrients from the space between the cell wall and plasma membrane but do not penetrate the membrane itself. Larger (usually botanical, not fungal) haustoria do this at the tissue level. The etymology of the name corresponds to the Latin word ''haustor'' meaning ''the one who draws, drains or drinks'', and refers to the action performed by the outgrowth. In fungi Fungi in all major divisions form haustoria. Haustoria take several forms. Generally, on penetration, the fungus increases the surface ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conidium
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), 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. 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 sometimes used. Conidiogenesis There are two main types of co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floriculture
Floriculture, or flower farming, is a branch of horticulture concerned with the cultivation of flowering and ornamental plants for gardens and for floristry, comprising the floral industry. The development of new varieties by plant breeding is a major occupation of floriculturists. Overview Floriculture crops include bedding plants, houseplants, flowering garden and pot plants, cut cultivated greens, and cut flowers. As distinguished from nursery crops, floriculture crops are generally herbaceous. Bedding and garden plants consist of young flowering plants (annuals and perennials) and vegetable plants. They are grown in cell packs (in flats or trays), in pots, or in hanging baskets, usually inside a controlled environment, and sold largely for gardens and landscaping. ''Pelargonium'' ("geraniums"), ''Impatiens'' ("busy lizzies"), and ''Petunia'' are the best-selling bedding plants. The many cultivars of ''Chrysanthemum'' are the major perennial garden plant in the United S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusarium Wilt
Fusarium wilt is a common vascular wilt fungal disease, exhibiting symptoms similar to Verticillium wilt. This disease has been investigated extensively since the early years of this century. The pathogen that causes Fusarium wilt is ''Fusarium oxysporum'' (''F. oxysporum'').Snyder, W.C. and Hansen, H.N. 1940. The species concept in Fusarium. Am. J. Bot. 27:64-67. The species is further divided into ''formae speciales'' based on host plant. Hosts and symptoms The fungal pathogen ''Fusarium oxysporum'' affects a wide variety of hosts of any age. Tomato, tobacco, legumes, cucurbits, sweet potatoes and banana are a few of the most susceptible plants, but it also infects other herbaceous plants. ''F. oxysporum'' generally produces symptoms such as wilting, chlorosis, necrosis, premature leaf drop, browning of the vascular system, stunting and damping-off. The most important of these is vascular wilt. Fusarium wilt starts out looking like vein clearing on the younger leaves and droo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusarium Oxysporum
''Fusarium oxysporum'' (Schlecht as emended by Snyder and Hansen), an ascomycete fungus, comprises all the species, varieties and forms recognized by Wollenweber and Reinking within an infrageneric grouping called section Elegans. It is part of the family Nectriaceae. Although their predominant role in native soils may be as harmless or even beneficial plant endophytes or soil saprophytes, many strains within the ''F. oxysporum'' complex are soil borne pathogens of plants, especially in agricultural settings. Taxonomy While the species, as defined by Snyder and Hansen, has been widely accepted for more than 50 years, more recent work indicates this taxon is actually a genetically heterogeneous polytypic morphospecies, whose strains represent some of the most abundant and widespread microbes of the global soil microflora. Genome The ' family of transposable elements was first discovered by Daboussi ''et al.'', 1992 in several ''formae speciales'' and Davière ''et al.'', 2001 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypha
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or more cells surrounded by a tubular cell wall. In most fungi, hyphae are divided into cells by internal cross-walls called "septa" (singular septum). Septa are usually perforated by pores large enough for ribosomes, mitochondria, and sometimes nuclei to flow between cells. The major structural polymer in fungal cell walls is typically chitin, in contrast to plants and oomycetes that have cellulosic cell walls. Some fungi have aseptate hyphae, meaning their hyphae are not partitioned by septa. Hyphae have an average diameter of 4–6 µm. Growth Hyphae grow at their tips. During tip growth, cell walls are extended by the external assembly and polymerization of cell wall components, and the internal production of new cell membrane. The S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oomycete
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 oospore is the result of contact between hyphae of male antheridia and female oogonia; these spores can overwinter and are known as resting spores. Asexual reproduction involves the formation of chlamydospores and sporangia, producing motile zoospores. Oomycetes occupy both saprophytic and pathogenic lifestyles, and include some of the most notorious pathogens of plants, causing devastating diseases such as late blight of potato and sudden oak death. One oomycete, the mycoparasite '' Pythium oligandrum'', is used for biocontrol, attacking plant pathogenic fungi. The oomycetes are also often referred to as water molds (or water moulds), although the water-preferring nature which led to that name is not true of most species, which are terrestrial pathogens. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytophthora Infestans
''Phytophthora infestans'' is an oomycete or water mold, a fungus-like microorganism that causes the serious potato and tomato disease known as late blight or potato blight. Early blight, caused by ''Alternaria solani'', is also often called "potato blight". Late blight was a major culprit in the 1840s European, the 1845–1852 Irish, and the 1846 Highland potato famines. The organism can also infect some other members of the Solanaceae. The pathogen is favored by moist, cool environments: sporulation is optimal at in water-saturated or nearly saturated environments, and zoospore production is favored at temperatures below . Lesion growth rates are typically optimal at a slightly warmer temperature range of . Etymology The genus name ''Phytophthora'' comes from the Greek –(), meaning : "plant" – plus the Greek (), meaning : "decay, ruin, perish". The species name ''infestans'' is the present participle of the Latin verb , meaning : "attacking, destroying", from which we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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