The chestnuts are the deciduous trees and shrubs in the genus Castanea, in the beech family Fagaceae. The name also refers to the edible nuts they produce. They are native to temperate regions of the Northern Hemisphere.
The American chestnut is a large, fast-growing deciduous tree of the beech family native to eastern North America. As is true of all species in the genus Castanea, the American chestnut produces burred fruit with edible nuts. The American chestnut was one of the most important forest trees throughout its range.
Brown rot may refer to the following diseases:
Botrytis cinerea is a necrotrophic fungus that affects many plant species, although its most notable hosts may be wine grapes. In viticulture, it is commonly known as "botrytis bunch rot"; in horticulture, it is usually called "grey mould" or "gray mold".
The Oomycetes, or Oomycota, form a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms within the Stramenopiles. 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, although the water-preferring nature which led to that name is not true of most species, which are terrestrial pathogens.
Phytophthora cinnamomi, also known as cinnamon fungus, is a soil-borne water mould that produces an infection which causes a condition in plants variously called "dieback", "root rot", or, "ink disease".
Rhizoctonia solani is a species of fungus in the order Cantharellales. Basidiocarps are thin, effused, and web-like, but the fungus is more typically encountered in its anamorphic state, as hyphae and sclerotia. The name Rhizoctonia solani is currently applied to a complex of related species that await further research. In its wide sense, Rhizoctonia solani is a facultative plant pathogen with a wide host range and worldwide distribution. It causes various plant diseases such as root rot, damping off, and wire stem. It can also form mycorrhizal associations with orchids.
Damping off is a horticultural disease or condition, caused by several different pathogens that kill or weaken seeds or seedlings before or after they germinate. It is most prevalent in wet and cool conditions.
Armillaria luteobubalina, commonly known as the Australian honey fungus, is a species of mushroom in the family Physalacriaceae. Widely distributed in southern Australia, the fungus is responsible for a disease known as Armillaria root rot, a primary cause of Eucalyptus tree death and forest dieback. It is the most pathogenic and widespread of the six Armillaria species found in Australia. The fungus has also been collected in Argentina and Chile. Fruit bodies have cream- to tan-coloured caps that grow up to 10 cm (4 in) in diameter and stems that measure up to 20 cm (8 in) long by 1.5 cm (1 in) thick. The fruit bodies, which appear at the base of infected trees and other woody plants in autumn (March–April), are edible, but require cooking to remove the bitter taste. The fungus is dispersed through spores produced on gills on the underside of the caps, and also by growing vegetatively through the root systems of host trees. The ability of the fungus to spread vegetatively is facilitated by an aerating system that allows it to efficiently diffuse oxygen through rhizomorphs—rootlike structures made of dense masses of hyphae.
Thielaviopsis basicola is the plant-pathogen fungus responsible for black root rot disease. This particular disease has a large host range, affecting woody ornamentals, herbaceous ornamentals, agronomic crops, and even vegetable crops. Examples of susceptible hosts include petunia, pansy, poinsettia, tobacco, cotton, carrot, lettuce, tomato, and others. Symptoms of this disease resemble nutrient deficiency but are truly a result of the decaying root systems of plants. Common symptoms include chlorotic lower foliage, yellowing of plant, stunting or wilting, and black lesions along the roots. The lesions along the roots may appear red at first, getting darker and turning black as the disease progresses. Black root lesions that begin in the middle of a root can also spread further along the roots in either direction. Due to the nature of the pathogen, the disease can easily be identified by the black lesions along the roots, especially when compared to healthy roots. The black lesions that appear along the roots are a result of the formation of chlamydospores, resting spores of the fungus that contribute to its pathogenicity. The chlamydospores are a dark brown-black color and cause the "discoloration" of the roots when they are produced in large amounts.
Phytophthora × cambivora is a plant pathogen that causes ink disease in European chestnut trees. Ink disease, also caused by Phytophthora cinnamomi, is thought to have been present in Europe since the 18th century, and causes chestnut trees to wilt and die; major epidemics occurred during the 19th and 20th centuries. P. cinnamomi and P. × cambivora are now present throughout Europe since the 1990s. Ink disease has resurged, often causing high mortality of trees, particularly in Portugal, Italy, and France. It has also been isolated from a number of different species since the 1990s, including:
Lasiodiplodia theobromae is a plant pathogen with a very wide host range. It causes rotting and dieback in most species it infects. It is a common post harvest fungus disease of citrus known as stem-end rot. It is a cause of bot canker of grapevine. It also infects Biancaea sappan, a species of flowering tree also known as Sappanwood.
Diaporthales is an order of sac fungi.
Gnomonia fructicola is a fungal plant pathogen on strawberries causing leaf spot disease. It can overwinter on leaves and fruits of Fragaria spp. (Rosaceae), occasionally pathogenic on fruits causing strawberry stem-end rot. The causal organism has often been referred to as Gnomoniacomari, now considered Gnomoniopsiscomari. It occurs in Canada, Europe and U.S.A..
Hypovirus is a genus of viruses, in the family Hypoviridae. Fungi serve as natural hosts. There are four species in this genus. Infection reduces the virulence of its parasitic host, making it a hyperparasite useful for blight control.
Dryocosmus kuriphilus is a species of gall wasp known by the common names chestnut gall wasp, Oriental chestnut gall wasp, and Asian chestnut gall wasp. It is native to China and it is known in many other parts of the world, particularly the Northern Hemisphere, as an introduced species and an invasive horticultural pest. It attacks many species of chestnut, including most cultivated varieties. It is considered the world's worst pest of chestnuts.
Trichothecium roseum is a fungus in the division Ascomycota first reported in 1809. It is characterized by its flat and granular colonies which are initially white and develop to be light pink in color. This fungus reproduces asexually through the formation of conidia with no known sexual state. Trichothecium roseum is distinctive from other species of the genus Trichothecium in its characteristic zigzag patterned chained conidia. It is found in various countries worldwide and can grow in a variety of habitats ranging from leaf litter to fruit crops. Trichothecium roseum produces a wide variety of secondary metabolites including mycotoxins, such as roseotoxins and trichothecenes, which can infect and spoil a variety of fruit crops. It can act as both a secondary and opportunistic pathogen by causing pink rot on various fruits and vegetables and thus has an economical impact on the farming industry. Secondary metabolites of T. roseum, specifically Trichothecinol A, are being investigated as potential anti-metastatic drugs. Several agents including harpin, silicon oxide, and sodium silicate are potential inhibitors of T. roseum growth on fruit crops. Trichothecium roseum is mainly a plant pathogen and has yet to show a significant impact on human health.
Neoscytalidium dimidiatum was first described in 1933 as Hendersonula toruloidea from diseased orchard trees in Egypt. Decades later, it was determined to be a causative agent of human dermatomycosis-like infections and foot infections predominantly in tropical areas; however the fungus is considered to be widespread. A newer name, Scytalidium dimidiatum, was applied to a synanamorph of Nattrassia mangiferae, otherwise known as Neofusicoccum mangiferae. Substantial confusion has arisen in the literature on this fungus resulting from the use of multiple different names including Torula dimidiata, Fusicoccum dimidiatum, Scytalidium dimidiatum, and Hendersonula toruloidea. Additionally, Scytalidium lignicola and Scytalidium lignicolum are often considered earlier names of N. dimidiatum.
Rhizopus stolonifer is commonly known as black bread mold. It is a member of Zygomycota and considered the most important species in the genus Rhizopus. It is one of the most common fungi in the world and has a global distribution although it is most commonly found in tropical and subtropical regions. It is a common agent of decomposition of stored foods. Like other members of the genus Rhizopus, R. stolonifer grows rapidly, mostly in indoor environments.
Gnomoniopsis castaneae is a fungus of the order Diaporthales that is the most important cause of brown chestnut rot, an emerging disease that damages the fruit of chestnuts. It also causes cankers and necrosis on leaves and on chestnut galls caused by the gall wasp, Dryocosmus kuriphilus. Additionally, it can cause cankers on other chestnut species, red oak, hazelnut trees, less severe damage to some nut trees, and lives as an endophyte on other nut trees. The disease has been reported in Europe, Oceania, and has recently been found in North America; for this reason, the fungus is considered a potential threat to the reintroduction of the American chestnut.
