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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".
Magnaporthe grisea, also known as rice blast fungus, rice rotten neck, rice seedling blight, blast of rice, oval leaf spot of graminea, pitting disease, ryegrass blast, Johnson spot, neck blast, and Imochi (Japanese:稲熱) is a plant-pathogenic fungus and model organism that causes a serious disease affecting rice. It is now known that M. grisea consists of a cryptic species complex containing at least two biological species that have clear genetic differences and do not interbreed. Complex members isolated from Digitaria have been more narrowly defined as M. grisea. The remaining members of the complex isolated from rice and a variety of other hosts have been renamed Magnaporthe oryzae, within the same M. grisea complex. Confusion on which of these two names to use for the rice blast pathogen remains, as both are now used by different authors.
A sclerotium, is a compact mass of hardened fungal mycelium containing food reserves. One role of sclerotia is to survive environmental extremes. In some higher fungi such as ergot, sclerotia become detached and remain dormant until favorable growth conditions return. Sclerotia initially were mistaken for individual organisms and described as separate species until Louis René Tulasne proved in 1853 that sclerotia are only a stage in the life cycle of some fungi. Further investigation showed that this stage appears in many fungi belonging to many diverse groups. Sclerotia are important in the understanding of the life cycle and reproduction of fungi, as a food source, as medicine, and in agricultural blight management.
White onion or Allium cepa are a cultivar of dry onion which have a distinct light and mild flavour profile. Much like red onions, they have a high sugar and low sulphur content, and thus have a relatively short shelf life. White onions are used in a variety of dishes such as that of Mexican and European origin. Their uses in dishes often relate to their mild nature, they are often included in dishes to provide a light, fresh and sour taste to dishes and are often added uncooked to dishes such as salads.
Cochliobolus miyabeanus is a fungus that causes brown spot disease in rice.
This is a glossary of some of the terms used in phytopathology.
Rhizoctonia solani is a plant pathogenic fungus with a wide host range and worldwide distribution. It was discovered more than 100 years ago. R. solani frequently exists as thread-like growth on plants or in culture, and is considered a soil-borne pathogen. R. solani is best known to cause various plant diseases such as collar rot, root rot, damping off, and wire stem. R. solani attacks its hosts when they are in their early stages of development, such as seeds and seedlings, which are typically found in the soil. The pathogen is known to cause serious plant losses by attacking primarily the roots and lower stems of plants. Although it has a wide range of hosts, its main targets are herbaceous plants. R. solani is a basidiomycete fungus but the teleomorph stage is not prominent. Occasionally, sexual spores (basidiospores) are produced on infected plants. The disease cycle of R. solani is important in management and control of the pathogen. The pathogen is not currently known to produce any asexual spores (conidia), though it is considered to have an asexual lifecycle perpetuated through sclerotia.
Athelia rolfsii is a corticioid fungus in the family Atheliaceae. It is a facultative plant pathogen and is the causal agent of "southern blight" disease in crops.
Macrophomina phaseolina is a Botryosphaeriaceae plant pathogen fungus that causes damping off, seedling blight, collar rot, stem rot, charcoal rot, basal stem rot, and root rot on many plant species.
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 tuber blight on potato. Despite the name "early," foliar symptoms usually occur on older leaves. If uncontrolled, early blight can cause significant yield reductions. Primary methods of controlling this disease include preventing long periods of wetness on leaf surfaces and applying fungicides. Early blight can also be caused by Alternaria tomatophila, which is more virulent on stems and leaves of tomato plants than Alternaria solani.
Phomopsis obscurans is a common fungus found in strawberry plants, which causes the disease of leaf blight. Common symptoms caused by the pathogen begin as small circular reddish-purple spots and enlarge to form V-shaped lesions that follow the vasculature of the plant's leaves. Although the fungus infects leaves early in the growing season when the plants are beginning to develop, leaf blight symptoms are most apparent on older plants towards the end of the growing season. The disease can weaken strawberry plants through the destruction of foliage, which results in reduced yields. In years highly favorable for disease development, leaf blight can ultimately lead to the death of the strawberry plants. A favorable environment for the growth and development of the Phomopsis obscurans pathogen is that of high temperature, high inoculum density, a long period of exposure to moisture, and immature host tissue. In the case of disease management, a conjunction of cultural practices is the most effective way of reducing the infection.
Sarocladium oryzae (Sawada) is a plant pathogen causing the sheath rot disease of rice and bamboo blight in Asia.
Elsinoë ampelina is a plant pathogen, which is the causal agent of anthracnose on grape.
Grey leaf spot (GLS) is a foliar fungal disease that affects maize, also known as corn. GLS is considered one of the most significant yield-limiting diseases of corn worldwide. There are two fungal pathogens that cause GLS: Cercospora zeae-maydis and Cercospora zeina. Symptoms seen on corn include leaf lesions, discoloration (chlorosis), and foliar blight. Distinct symptoms of GLS are rectangular, brown to gray necrotic lesions that run parallel to the leaf, spanning the spaces between the secondary leaf veins. The fungus survives in the debris of topsoil and infects healthy crops via asexual spores called conidia. Environmental conditions that best suit infection and growth include moist, humid, and warm climates. Poor airflow, low sunlight, overcrowding, improper soil nutrient and irrigation management, and poor soil drainage can all contribute to the propagation of the disease. Management techniques include crop resistance, crop rotation, residue management, use of fungicides, and weed control. The purpose of disease management is to prevent the amount of secondary disease cycles as well as to protect leaf area from damage prior to grain formation. Corn grey leaf spot is an important disease of corn production in the United States, economically significant throughout the Midwest and Mid-Atlantic regions. However, it is also prevalent in Africa, Central America, China, Europe, India, Mexico, the Philippines, northern South America, and Southeast Asia. The teleomorph of Cercospora zeae-maydis is assumed to be Mycosphaerella sp.
Southern corn leaf blight (SCLB) is a fungal disease of maize caused by the plant pathogen Bipolaris maydis.
Stromatinia cepivora is a fungus in the division Ascomycota. It is the teleomorph of Sclerotium cepivorum, the cause of white rot in onions, garlic, and leeks. The infective sclerotia remain viable in the soil for many years and are stimulated to germinate by the presence of a susceptible crop.
Gummy stem blight is a cucurbit-rot disease caused by the fungal plant pathogen Didymella bryoniae. Gummy stem blight can affect a host at any stage of growth in its development and affects all parts of the host including leaves, stems and fruits. Symptoms generally consist of circular dark tan lesions that blight the leaf, water soaked leaves, stem cankers, and gummy brown ooze that exudes from cankers, giving it the name gummy stem blight. Gummy stem blight reduces yields of edible cucurbits by devastating the vines and leaves and rotting the fruits. There are various methods to control gummy stem blight, including use of treated seed, crop rotation, using preventative fungicides, eradication of diseased material, and deep plowing previous debris.
Cladosporium fulvum is an Ascomycete called Passalora fulva, a non-obligate pathogen that causes the disease on tomato known as the tomato leaf mold. P. fulva only attacks tomato plants, especially the foliage, and it is a common disease in greenhouses, but can also occur in the field. The pathogen is likely to grow in humid and cool conditions. In greenhouses, this disease causes big problems during the fall, in the early winter and spring, due to the high relative humidity of air and the temperature, that are propitious for the leaf mold development. This disease was first described in the North Carolina, by Mordecai Cubitt Cooke (1883), on cultivated tomato, although it is originally from South and Central America. The causal fungus of tomato leaf mold may also be referred to as Cladosporium fulvum, a former name.
Botrytis squamosa is a fungus that causes leaf blight on onion that is distinctly characterized by the two stages – leaf spotting followed by blighting. The pathogen is an ascomycete that belongs to the family Sclerotiniaceae in the order Helotiales. The lesions start out as whitish streaks and take on a yellow tinge as they mature. They cause yield losses up to 30%. This fungus is endemic to the USA and has also been reported in Europe, Asia, and Australia. Typical management of this disease includes chemical fungicides with significant efforts being made to establish a means of biological control.
Rice-sheath blight is a disease caused by Rhizoctonia solani, a basidiomycete, that causes major limitations on rice production in India and other countries of Asia. It is also a problem in the southern US, where rice is also produced. It can decrease yield up to 50%, and reduce its quality. It causes lesions on the rice plant, and can also cause pre- and post-emergence seedling blight, banded leaf blight, panicle infection and spotted seed.
References
- ↑ "LSU AgCenter". www.lsuagcenter.com. Retrieved 2017-11-26.
- ↑ "stem rot (Magnaporthe salvinii)". www.plantwise.org. Retrieved 2017-10-16.
- ↑ Groth, Don. "Stem Rot of Rice" (PDF). Louisiana Plant Pathology. Retrieved October 15, 2017.
- ↑ Talbot, Nicholas (2009). "Under Pressure: Investigating the Biology of Plant Infection by Magnaporthe oryza". Fungal Molecular Plant-Microbe Interactions. 7: 185–186 – via Plant Pathology Commons.
- ↑ Sharma, P.D. (2004). Plant Pathology. New Delhi, India: Rastogi Publications. pp. 279–280. ISBN 81-7133-700-7.
- ↑ Ou, S.H. (1985). Rice Disease. Great Britain: Commonwealth Mycological Institute. pp. 254–256. ISBN 0-85198-545-9.
- ↑ Hussain, Shaukat (1993). "Effect of Tillage Practices on the Population and Viability of Sclerotia of Sclerotium oryzae and Yield of Rice" (PDF). Pakistan Journal of Botany. 25: 232–234.
- ↑ Espino, Luis. "California Rice Diseases" (PDF). University of California Agriculture and Natural Resources Cooperative Extension. Retrieved October 24, 2017.
- ↑ Syngenta US. "Quadris Flowable fungicide".
