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Alternate Host
A heteroecious parasite is one that requires at least two hosts. The ''primary host'' is the host in which the parasite spends its adult life; the other is the ''secondary host''. Both hosts are required for the parasite to complete its life cycle. This can be contrasted with an autoecious parasite which can complete its life cycle on a single host species. Many rust fungi have heteroecious life cycles: In parasitology, heteroxeny, or heteroxenous development, is a synonymous term that characterizes a parasite whose development involves several hosts. Fungal examples * ''Gymnosporangium'' (Cedar-apple rust): the juniper is the primary ( telial) host and the apple, pear or hawthorn is the secondary ( aecial) host. * '' Cronartium ribicola'' (White pine blister rust): the primary host are white pines, and currants the secondary. * '' Hemileia vastatrix'' (Coffee rust): the primary host is coffee plant, and the alternate host is unknown. * '' Puccinia graminis'' (Stem rust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasite
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has characterised parasites as "predators that eat prey in units of less than one". Parasites include single-celled protozoans such as the agents of malaria, sleeping sickness, and amoebic dysentery; animals such as hookworms, lice, mosquitoes, and vampire bats; fungi such as honey fungus and the agents of ringworm; and plants such as mistletoe, dodder, and the broomrapes. There are six major parasitic strategies of exploitation of animal hosts, namely parasitic castration, directly transmitted parasitism (by contact), trophicallytransmitted parasitism (by being eaten), vector-transmitted parasitism, parasitoidism, and micropredation. One major axis of classification concerns invasiveness: an endoparasite lives inside the host's body ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribes
''Ribes'' is a genus of about 200 known species of flowering plants, most of them native to the temperate regions of the Northern Hemisphere. The various species are known as currants or gooseberries, and some are cultivated for their edible fruit or as ornamental plants. ''Ribes'' is the only genus in the family Grossulariaceae. Description ''Ribes'' species are medium shrublike plants with marked diversity in strikingly diverse flowers and fruit. They have either palmately lobed or compound leaves, and some have thorns. The sepals of the flowers are larger than the petals, and fuse into a tube or saucer shape. The ovary is inferior, maturing into a berry with many seeds. Taxonomy ''Ribes'' is the single genus in the Saxifragales family Grossulariaceae. Although once included in the broader circumscription of Saxifragaceae '' sensu lato'', it is now positioned as a sister group to Saxifragaceae ''sensu stricto''. Subdivision First treated on a worldwide basis in 1907, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anders Sandøe Ørsted (botanist)
Anders Sandøe Ørsted, also written as ''Anders Sandoe Oersted'' or ''Anders Sandö Örsted'' (21 June 1816 – 3 September 1872) was a Danish botanist, mycologist, zoologist and marine biologist. He was the nephew of physicist Hans Christian Ørsted and of politician Anders Sandøe Ørsted. Career In his early career, he published on Danish and Arctic nematodes and on the zonation of marine algae in Øresund. Between 1845 and 1848, he travelled extensively in Central America and the Caribbean and published numerous papers on the flora, concentrating on the plant families Acanthaceae and Fagaceae. One of his better known publications i''L'Amérique Centrale'' He was appointed professor of botany at the University of Copenhagen in 1851, a post he held until 1862. He was succeeded by Ferdinand Didrichsen. His studies of what has since been known as juniper-pear rust showed that this fungus annually switches between two hosts; '' Juniperus sabina'' is the primary ( t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autoecious
A heteroecious parasite is one that requires at least two hosts. The ''primary host'' is the host in which the parasite spends its adult life; the other is the ''secondary host''. Both hosts are required for the parasite to complete its life cycle. This can be contrasted with an autoecious parasite which can complete its life cycle on a single host species. Many rust fungi have heteroecious life cycles: In parasitology, heteroxeny, or heteroxenous development, is a synonymous term that characterizes a parasite whose development involves several hosts. Fungal examples * ''Gymnosporangium'' (Cedar-apple rust): the juniper is the primary ( telial) host and the apple, pear or hawthorn is the secondary ( aecial) host. * '' Cronartium ribicola'' (White pine blister rust): the primary host are white pines, and currants the secondary. * '' Hemileia vastatrix'' (Coffee rust): the primary host is coffee plant, and the alternate host is unknown. * '' Puccinia graminis'' (Stem rust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puccinia Porri
''Puccinia porri'' (previously known as ''Puccinia allii'') is a species of rust fungus that causes leek rust. It affects leek, garlic, onion, and chives, and usually appears as bright orange spots on infected plants. Fungus ''Puccinia porri'' is autoecious, meaning that all stages of its life cycle occur on the host plant. While ''P. porri'' and ''P. mixta'' were originally thought to be separate species, by 1984 they were all generally categorized under ''P. allii''. The fungus causes leek rust, but it also affects garlic, onion, and chives. In 2016, Alistair McTaggart and colleagues used molecular phylogenetic analysis to sort out collections of fungi labeled as ''Puccinia allii'' occurring in Australia, and placed this name in synonymy with ''Puccinia porri''. Conditions for growth Leek rust appears seasonally, starting in the middle of August. It develops more quickly in warmer weather, so conversely, cold spells can reduce the onset of symptoms. If a leek reaches ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phakopsora Pachyrhizi
''Phakopsora pachyrhizi'' is a plant pathogen. It causes Asian soybean rust. Hosts ''Phakopsora pachyrhizi'' is an obligate biotrophic pathogen that causes Asian soybean rust. ''Phakopsora pachyrhizi'' is able to affect up to 31 different plant species that belong to 17 different genera under natural conditions. Experiments in laboratories were able to use ''Phakopsora pachyrhizi'' to infect 60 more plant species. The main hosts are ''Glycine max'' (soybean), ''Glycine soja'' (wild soybean), and ''Pachyrhizus erosus'' (Jicama). *Preferred hosts. Other hosts were minor or determined experimentally under artificial conditions. Symptoms The disease forms tan to dark-brown or reddish-brown lesions with one to many prominent, globe-like orifices. Urediniospores form from these pores. At initial stages, small yellow spots are formed on the surface of the leaf. These spots may be better observed using assistance of a light source. As the disease progresses, lesions start to fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phakopsora Meibomiae
The Phakopsoraceae are a family of rust fungi in the order Pucciniales. The family contains 18 genera and 205 species. Genera *'' Aeciure'' *'' Arthuria'' *'' Batistopsora'' *'' Bubakia'' *'' Catenulopsora'' *'' Cerotelium'' *'' Crossopsora'' *'' Dasturella'' *'' Kweilingia'' *'' Macabuna'' *'' Monosporidium'' *'' Newinia'' *'' Nothoravenelia'' *''Phakopsora'' *'' Phragmidiella'' *''Physopella ''Physopella'' is a genus of fungal plant pathogen in the family Phakopsoraceae The Phakopsoraceae are a family of rust fungi in the order Pucciniales Rusts are plant diseases caused by pathogenic fungi of the order Pucciniales (previously ...'' *'' Pucciniostele'' *'' Scalarispora'' *'' Stakmania'' Kamat & Sathe, 1968 *'' Tunicopsora'' *'' Uredendo'' *'' Uredopeltis'' *'' Uredostilbe'' References External links * Pucciniales Basidiomycota families {{Basidiomycota-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhamnus (genus)
''Rhamnus'' is a genus of about 110 accepted species of shrubs or small trees, commonly known as buckthorns, in the family Rhamnaceae. Its species range from tall (rarely to ) and are native mainly in east Asia and North America, but found throughout the temperate and subtropical Northern Hemisphere, and also more locally in the subtropical Southern Hemisphere in parts of Africa and South America. One species, the common buckthorn (''Rhamnus cathartica''), is able to flourish as an invasive plant in parts of Canada and the U.S., where it has become naturalized. Both deciduous and evergreen species occur. The leaves are simple, long, and arranged alternately, in opposite pairs, or almost paired (subopposite). One distinctive character of many buckthorns is the way the veination curves upward towards the tip of the leaf. The plant bears fruits which are black or red berry-like drupes. The name is due to the woody spine on the end of each twig in many species. One species i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puccinia Coronata
''Puccinia coronata'' is a plant pathogen and causal agent of oat and barley crown rust. The pathogen occurs worldwide, infecting both wild and cultivated oats. Crown rust poses a threat to barley production, because the first infections in barley occur early in the season from local inoculum. Crown rusts have evolved many different physiological races within different species in response to host resistance. Each pathogenic race can attack a specific line of plants within the species typical host. For example, there are over 290 races of ''P. coronata''. Crops with resistant phenotypes are often released, but within a few years virulent races have arisen and ''P. coronata'' can infect them. Symptoms Uredinia are linear, light orange, and occur mostly on the leaf blades but occasionally occur also on leaf sheaths, peduncles and awns. Extensive chlorosis is often associated with the uredinia. Telia are mostly linear, black to dark brown, and are covered by the host epidermis. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puccinia Graminis
Stem rust, also known as cereal rust, black rust, red rust or red dust, is caused by the fungus ''Puccinia graminis'', which causes significant disease in cereal crops. Crop species that are affected by the disease include bread wheat, durum wheat, barley and triticale. These diseases have affected cereal farming throughout history. The annual recurrence of stem rust of wheat in North Indian plains was discovered by Prof. K.C. Mehta. Since the 1950s, wheat strains bred to be resistant to stem rust have become available. Fungicides effective against stem rust are available as well. In 1999 a new virulent race of stem rust was identified against which most current wheat strains show no resistance. The race was named TTKSK (e.g. isolate Ug99). An epidemic of stem rust on wheat caused by race TTKSK spread across Africa, Asia and the Middle East, causing major concern due to the large numbers of people dependent on wheat for sustenance, thus threatening global food security. An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemileia Vastatrix
''Hemileia vastatrix'' is a multicellular basidiomycete fungus of the order Pucciniales (previously also known as Uredinales) that causes coffee leaf rust (CLR), a disease affecting the coffee plant. Coffee serves as the obligate host of coffee rust, that is, the rust must have access to and come into physical contact with coffee (''Coffea sp.'') in order to survive. CLR is one of the most economically important diseases of coffee, worldwide. Previous epidemics have destroyed coffee production of entire countries. In more recent history, an epidemic in Central America in 2012 reduced the region's coffee output by 16%. The primary pathological mechanism of the fungus is a reduction in the plant's ability to derive energy through photosynthesis by covering the leafs with fungus spores and/or causing leaves to drop from the plant. The reduction in photosynthetic ability (plant's metabolism) results in a reduction in quantity and quality of flower and fruit production, which ul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinus Classification
''Pinus'', the pines, is a genus of approximately 111 extant tree and shrub species. The genus is currently split into two subgenera: subgenus ''Pinus'' (hard pines), and subgenus ''Strobus'' (soft pines). Each of the subgenera have been further divided into sections based on chloroplast DNA sequencing and whole plastid genomic analysis. Older classifications split the genus into three subgenera – subgenus ''Pinus'', subgenus ''Strobus'', and subgenus ''Ducampopinus'' ( pinyon, bristlecone and lacebark pines) – based on cone, seed and leaf characteristics. DNA phylogeny has shown that species formerly in subgenus ''Ducampopinus'' are members of subgenus ''Strobus'', so ''Ducampopinus'' is no longer used. The species of subgenus ''Ducampopinus'' were regarded as intermediate between the other two subgenera. In the modern classification, they are placed into subgenus ''Strobus'', yet they did not fit entirely well in either so they were classified in a third subgenu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
