''Alternaria'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of Deuteromycetes fungi. All species are known as major

plant pathogens Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomyc ...

. They are also common

allergen An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies. In technical terms ...

s in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, cou ...

. They are present in the human mycobiome and readily cause

opportunistic infection An opportunistic infection is an infection caused by pathogens (bacteria, fungi, parasites or viruses) that take advantage of an opportunity not normally available. These opportunities can stem from a variety of sources, such as a weakened immune ...

s in

immunocompromised Immunodeficiency, also known as immunocompromisation, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that a ...

people such as

AIDS Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual m ...

patients. There are 299 species in the genus; they are ubiquitous in the environment and are a natural part of fungal flora almost everywhere. They are normal agents of decay and

decomposition Decomposition or rot is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is e ...

. The

spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

s are airborne and found in the soil and water, as well as indoors and on objects. The club-shaped spores are single or form long chains. They can grow thick colonies which are usually green, black, or gray. At least 20% of

agricultural Agriculture or farming is the practice of cultivating Plant, plants and livestock. Agriculture was the key development in the rise of Sedentism, sedentary human civilization, whereby farming of Domestication, domesticated species created food ...

spoilage is caused by ''Alternaria'' species, with the most severe losses reaching 80% of yield. Many human health disorders can be caused by these fungi, which grow on skin and

mucous membrane A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...

s, including on the eyeballs and within the respiratory tract. Allergies are common, but serious infections are rare, except in people with compromised immune systems. However, species of this fungal genus are often prolific producers of a variety of toxic compounds. The effects most of these compounds have on animal and plant health are not well known. Many species of alternaria modify their secondary metabolites by sulfoconjugation; however, the role of this process is not yet understood. The terms ''

alternariosis Alternariosis is an infection by ''Alternaria'', presenting cutaneously as focal, ulcerated papules and plaques. Treatment with itraconazole Itraconazole, sometimes abbreviated ITZ, is an antifungal medication used to treat a number of fungal i ...

'' and ''alternariatoxicosis'' are used for disorders in humans and animals caused by a fungus in this genus. Not all ''Alternaria'' species are pests and pathogens; some have shown promise as biocontrol agents against

invasive plant species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

. Some species have also been reported as endophytic microorganisms with highly bioactive metabolites. The genus is now known to be

polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ...

Species

Some species include: *''

Alternaria alternata ''Alternaria alternata'' is a fungus which has been recorded causing leaf spot and other diseases on over 380 host species of plant. It is an opportunistic pathogen on numerous hosts causing leaf spots, rots and blights on many plant parts. It ...

'' – Causes early blight of potato, Leaf spot disease in ''

Withania somnifera ''Withania somnifera'', known commonly as ashwagandha or winter cherry, is an evergreen shrub in the Solanaceae or nightshade family that grows in India, the Middle East, and parts of Africa. Several other species in the genus ''Withania'' are m ...

'' and can infest many other plants. It also causes upper respiratory infections in AIDS patients, asthma in people with sensitivity, and has been implicated in chronic rhinosinusitis. *''

Alternaria alternantherae ''Alternaria'' is a genus of Deuteromycetes fungi. All species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma. They ...

'' *''

Alternaria arborescens ''Alternaria'' is a genus of Deuteromycetes fungi. All species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma. They ...

'' – causes stem canker of

tomato The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...

*''

Alternaria arbusti ''Alternaria'' is a genus of Deuteromycetes fungi. All species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma. They ...

'' – causes leaf lesions on Asian pear *''

Alternaria blumeae ''Alternaria'' is a genus of Deuteromycetes fungi. All species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma. They ...

'' – causes lesions on ''Blumea aurita'' *''

Alternaria brassicae ''Alternaria brassicae'' is a plant pathogen able to infect most ''Brassica'' species including important crops such as broccoli, cabbage and oil seed rape. It causes damping off if infection occurs in younger plants and less severe leaf spot ...

'' – infests many vegetables and roses *''

Alternaria brassicicola ''Alternaria brassicicola'' is a fungal necrotrophic plant pathogen that causes black spot disease on a wide range of hosts, particularly in the genus of ''Brassica'', including a number of economically important crops such as cabbage, Chinese ca ...

'' – grows on

cole crops Cruciferous vegetables are vegetables of the family Brassicaceae (also called Cruciferae) with many genera, species, and cultivars being raised for food production such as cauliflower, cabbage, kale, garden cress, bok choy, broccoli, Brusse ...

*''

Alternaria burnsii ''Alternaria'' is a genus of Deuteromycetes fungi. All species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma. They ...

'' – causing cumin blossom blight *''

Alternaria carotiincultae ''Alternaria'' is a genus of Deuteromycetes fungi. All species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma. They ...

'' – causes leaf blight on

carrot The carrot ('' Daucus carota'' subsp. ''sativus'') is a root vegetable, typically orange in color, though purple, black, red, white, and yellow cultivars exist, all of which are domesticated forms of the wild carrot, ''Daucus carota'', nat ...

*''

Alternaria carthami ''Alternaria carthami'' is a plant pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be ref ...

'' *'' Alternaria celosiae'' *'' Alternaria cinerariae'' *''

Alternaria citri ''Alternaria citri'' is a fungal plant pathogen that causes black rot in citrus plants. Host and symptoms ''Alternaria citri'' is an ascomycete fungal plant pathogen that causes black rot in citrus plants. Specifically, certain lemon, lime, o ...

'' – causes black rot on

citrus ''Citrus'' is a genus of flowering plant, flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as Orange (fruit), oranges, Lemon, lemons, grapefruits, pomelos, and lim ...

plants *'' Alternaria conjuncta'' – grows on

parsnip The parsnip ('' Pastinaca sativa'') is a root vegetable closely related to carrot and parsley, all belonging to the flowering plant family Apiaceae. It is a biennial plant usually grown as an annual. Its long taproot has cream-colored skin an ...

*'' Alternaria cucumerina'' – grows on various cucurbits *''

Alternaria dauci ''Alternaria dauci'' is a plant pathogen. The English name of the disease it incites is "carrot leaf blight". Hosts and symptoms Alternaria Leaf Blight is a foliar disease of carrots caused by the fungus ''Alternaria dauci''. ''Alternaria dauc ...

'' – grows on carrot *'' Alternaria dianthi'' *''

Alternaria dianthicola ''Alternaria dianthicola'' is a fungal plant pathogen. References External links dianthicola Fungal plant pathogens and diseases Fungi described in 1945 {{fungus-plant-disease-stub ...

'' *'' Alternaria eichhorniae'' – infests

water hyacinth ''Pontederia crassipes'' (formerly ''Eichhornia crassipes''), commonly known as common water hyacinth is an aquatic plant native to South America, naturalized throughout the world, and often invasive outside its native range.Alternaria euphorbiicola'' – infests cole crops *'' Alternaria eureka'' *'' Alternaria gaisen'' – causes ringspot disease of pear *''

Alternaria helianthi ''Alternaria helianthi'' is a fungal plant pathogen causing a disease in sunflowers known as Alternaria blight of sunflower. As a pathogen ''Alternaria spp''. plant pathogens are found across the world, affecting a variety of species, includi ...

'' *''

Alternaria helianthicola ''Alternaria helianthicola'' is a fungal plant pathogen. References helianthicola Fungal plant pathogens and diseases Fungi described in 1977 Fungus species {{fungus-plant-disease-stub ...

'' *'' Alternaria hungarica'' *''

Alternaria infectoria ''Alternaria'' is a genus of Deuteromycetes fungi. All species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma. They ...

'' – infests

wheat Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...

*''

Alternaria japonica ''Alternaria japonica'' is a fungal plant pathogen. It is a cause of black spot disease in cruciferous plants. It is not a major source of crop loss, but is considered dangerous for plants during the seedling stage. Symptoms ''Alternaria japoni ...

'' – infests cole crops *'' Alternaria limicola'' – earliest diverging lineage of Section Porri *'' Alternaria linicola'' *'' Alternaria longipes'' – infects tobacco *''

Alternaria mali ''Alternaria mali'', also called alternaria blotch of apple, is a pathogenic fungus affecting plants. It is prevalent in the southern United States and elsewhere, and damages the leaves of infected apple trees. Pathogenesis ''Aleternaria mali'' ...

'' *'' Alternaria molesta'' – may cause skin lesions on porpoises *'' Alternaria panax'' – causes

ginseng Ginseng () is the root of plants in the genus ''Panax'', such as Korean ginseng ('' P. ginseng''), South China ginseng ('' P. notoginseng''), and American ginseng ('' P. quinquefolius''), typically characterized by the presence of ginsenosides an ...

blight *''

Alternaria perpunctulata ''Alternaria'' is a genus of Deuteromycetes fungi. All species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma. They ...

'' *''

Alternaria petroselini ''Alternaria'' is a genus of Deuteromycetes fungi. All species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma. They ...

'' – causes

parsley Parsley, or garden parsley (''Petroselinum crispum'') is a species of flowering plant in the family Apiaceae that is native to the central and eastern Mediterranean region (Sardinia, Lebanon, Israel, Cyprus, Turkey, southern Italy, Greece, Por ...

leaf blight *''

Alternaria porri ''Alternaria'' is a genus of Deuteromycetes fungi. All species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma. They ...

'' *'' Alternaria quercicola'' *''

Alternaria radicina ''Alternaria radicina'' is a fungal plant pathogen infecting carrots. References External links radicina Fungal plant pathogens and diseases Carrot diseases Fungi described in 1922 {{fungus-plant-disease-stub ...

'' – causes carrot decay *'' Alternaria raphani'' *''

Alternaria saponariae ''Alternaria saponariae'' is a fungal plant pathogen. References saponariae Fungal plant pathogens and diseases Fungi described in 1938 Fungus species {{fungus-plant-disease-stub ...

'' *'' Alternaria selini'' – causes parsley crown decay *'' Alternaria senecionis'' *''

Alternaria solani ''Alternaria solani'' is a fungal pathogen that produces a disease in tomato and potato plants called early blight. The pathogen produces distinctive "bullseye" patterned leaf spots and can also cause stem lesions and fruit rot on tomato and tu ...

'' – causes

early blight ''Alternaria solani'' is a fungal pathogen that produces a disease in tomato and potato plants called early blight. The pathogen produces distinctive "bullseye" patterned leaf spots and can also cause stem lesions and fruit rot on tomato and tube ...

in potatoes and tomatoes *'' Alternaria smyrnii'' – infests alexanders and parsleys *''

Alternaria tenuissima ''Alternaria tenuissima'' is a saprophytic fungus and opportunistic plant pathogen. It is cosmopolitan in distribution, and can colonize a wide range of plant hosts. Colonies of ''A. tenuissima'' produce chains on agar growth media. The fungus o ...

'' *''

Alternaria triticina ''Alternaria triticina'' is a fungal plant pathogen that causes leaf blight on wheat. ''A. triticina'' is responsible for the largest leaf blight issue in wheat and also causes disease in other major cereal grain crops. It was first identified ...

'' *'' Alternaria ventricosa'' *'' Alternaria zinniae''

References

Other sources

* * *

External links

''Alternaria'' as an indoor fungal allergen

Alternaria Online
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Mycology Online page

{{Taxonbar, from=Q133266 Dothideomycetes genera Fungal plant pathogens and diseases