Microdochium panattonianum | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Sordariomycetes |
Order: | Amphisphaeriales |
Family: | Amphisphaeriaceae |
Genus: | Microdochium |
Species: | M. panattonianum |
Binomial name | |
Microdochium panattonianum (Berl.) B. Sutton, Galea & T.V. Price, (1986) | |
Synonyms | |
Ascochyta suberosaRostr., (1938) Contents |
Microdochium panattonianum is a fungal plant pathogen. This pathogen causes anthracnose of lettuce, a disease which produces necrotic lesions in cultivated lettuce. [1] In extended periods of wet weather, M. panattonianum can cause significant crop-losses. The impact of this pathogen is exacerbated by farming lettuce without crop rotation, and by planting of susceptible lettuce varieties, such as Romaine lettuce. [2]
This fungus was first described in 1895 as Marssonia panattoniana by Augusto Napoleone Berlese, an Italian botanist and mycologist. [3] [4] In 1986, the species was moved to the genus Microdochium by Brian Charles Sutton, Victor J. Galea, and T.V. Price. [5]
This pathogen infects cultivated lettuce and Lactuca serriola , which is cultivated lettuce’s closest wild relative. [1] [6] The fungus has also been found to infect Cichorium and Crepis capillaris . [6] Necrotic lesions on plant leaves are the characteristic symptom of lettuce anthracnose. Lesions may also be on leaf veins, and are often close to the leaf base. [7] These lesions may fall out, creating "shot-holes" in the leaf. [2] Lesions first appear small, circular, and wet, and may elongate into an oval shape as the disease progresses. Lesion color ranges from dull yellow to reddish brown. [2]
Microdochium panattonianum has a hyphal growth form. [5] The hyphae are septate, branched, and hyaline. The hyphae occur in sub-epidermal and in epidermal tissue. In epidermal tissue, the fungal hyphae form dense wefts. The fungus forms conidia that produce either appressoria or germ tubes. This fungus requires free water for conidial germination. [5] Microsclerotia are also produced and are generally 35-65 micrometers in diameter [8]
Infection occurs when fungal germ tubes penetrate leaf stomata, or when appressoria penetrate the leaf epidermis. [1] Microsclerotia present in past crop debris will germinate under wet conditions where it will produce hyphae to increase growth and conidiospores that release asexual conidia as a secondary infection; which increases the pathogen’s infection zone. [9]
Incidences of this fungus have been recorded in Africa, Australia, Europe, North America, and South America. [6]
Locations where this pathogen has been discovered include Alaska, Australia, Brazil, Bulgaria, California, Canada, Chile, China, Cuba, Denmark, the eastern United States, Florida, Greece, Idaho, Jamaica, Libya, Mexico, Michigan, Missouri, New Zealand, North Carolina, Ohio, Oregon, Scotland, Serbia, Texas, Washington, and the West Indies. [6]
This pathogen is managed using cultural and chemical controls. Cultural controls can include elimination of prickly lettuce and other potential hosts from the vicinity of lettuce crops, sanitizing surfaces and equipment to remove soil and plant residue which may harbor the pathogen, destroying cull piles and discarded seedlings, and rotating crops. Minimizing periods of leaf wetness aids in control of this pathogen, which requires free water for spore dispersal and germination [5] [10] .Chemical controls can include application of Badge SC or other copper products, mancozeb, and strobilurin fungicides. [10]
Biol ogical controls may be employed as well. The bacterium Streptomyces lydicus (Actinovate) is used as a biological control against M. panattonianum. [10] Recent research has shown that the fungus Trichoderma applied to soil or sprayed in a liquid filtrate onto leaves helps to prevent lettuce anthracnose and reduce symptoms when infection does occur. [11]
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, wheat blast and Imochi (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.
Pyrenophora teres is a necrotrophic fungal pathogen of some plant species, the most significant of which are economically important agricultural crops such as barley. Toxins include aspergillomarasmine A and related compounds.
Glomerella graminicola is an economically important crop parasite affecting both wheat and maize where it causes the plant disease Anthracnose Leaf Blight.
Mycosphaerella brassicicola is a plant pathogen. The pathogen is the teleomorph phase of an ascomycete fungus, which causes the ring spot disease of brassicas. The supplementary anamorph phase Asteromella brassicae produces conidia through its asexual reproduction, however these spores are not confirmed to cause disease in host plants.
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.
Albugo is a genus of plant-parasitic oomycetes. Those are not true fungi (Eumycota), although many discussions of this organism still treat it as a fungus. The taxonomy of this genus is incomplete, but several species are plant pathogens. Albugo is one of three genera currently described in the family Albuginaceae, the taxonomy of many species is still in flux.
Alternaria dauci is a plant pathogen. The English name of the disease it incites is "carrot leaf 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 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.
Bremia lactucae is a plant pathogen. This microorganism causes a disease of lettuce denominated as downy mildew. Some other strains can be found on 36 genera of Asteraceae including Senecio and Sonchus. Experiments using sporangia from hosts do not infect lettuce and it is concluded that the fungus exists as a quantity of host-specific strains. Wild species, such as Lactuca serriola, or varieties of Lactuca can hold strains that infect lettuce, but these pathogens are not sufficiently common to seriously infect the plant.
Oidium mangiferae is a plant pathogen that infects mango trees causing powdery mildew. Powdery mildew of mango is an Ascomycete pathogen of the Erysiphales family that was initially described by Berthet in 1914, using samples collected from Brazil. O. mangiferae is found in all areas where mangoes have been raised long term, but is particularly widespread in India where both the host and the pathogen are native. Currently no teleomorph stage has been identified, but due to certain morphological characteristics it has been suggested that O. mangiferae belongs in the Erysiphe polygony group. Mango is the only known host for this pathogen, though O. mangiferae appears to be identical to fungi responsible for powdery mildew diseases on various other plant species, particularly oak, though some differences may be observed. In particular, the number of cells in conidiophores varies from 2 on mango to 3-5 on oak. O. mangiferae has been known to infect oak leaves in the laboratory, however due to the lack of a known teleomorph stage O. mangiferae is still considered to only be a pathogen of mango. Recent analysis of its ribosomal DNA suggests it is conspecific with Erysiphe alphitoides, the causative agent of powdery mildew in European oaks.
Exobasidium vexans is a plant pathogen affecting tea.
Acremonium strictum is an environmentally widespread saprotroph species found in soil, plant debris, and rotting mushrooms. Isolates have been collected in North and Central America, Asia, Europe and Egypt. A. strictum is an agent of hyalohyphomycosis and has been identified as an increasingly frequent human pathogen in immunosuppressed individuals, causing localized, disseminated and invasive infections. Although extremely rare, A. strictum can infect immunocompetent individuals, as well as neonates. Due to the growing number of infections caused by A. strictum in the past few years, the need for new medical techniques in the identification of the fungus as well as for the treatment of human infections has risen considerably.
Mycocentrospora acerina is a deuteromycete fungus that is a plant pathogen.
Pyrenochaeta lycopersici is a fungal plant pathogen, infecting tomatoes and causing corky root rot.
Colletotrichum coccodes is a plant pathogen, which causes anthracnose on tomato and black dot disease of potato. Fungi survive on crop debris and disease emergence is favored by warm temperatures and wet weather.
Colletotrichum lindemuthianum is a fungus which causes anthracnose, or black spot disease, of the common bean plant. 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.
Elsinoë ampelina is a plant pathogen, which is the causal agent of anthracnose on grape.
Alternaria helianthi is a fungal plant pathogen causing a disease in sunflowers known as Alternaria blight of sunflower.
Spring Black Stem is a common fungal, foliar disease caused by Ascochyta medicaginicola. Spring Black Stem is most commonly found in alfalfa, but also attacks certain clovers. The fungus survives in stubble from previous cuttings and spreads easily by rain splash, running water, and equipment. The disease is present in numerous alfalfa fields throughout the Northeast United States.
Pecan scab is the most economically significant disease of pecan trees in the southeastern United States. Venturia effusa is a fungal plant pathogen that causes pecan scab. The fungus causes lesions and tissue death on pecan twigs, petioles, leaves, nuts and shucks beginning in early spring, with multiple cycles of infection repeating until late summer. Wind and rain spread the fungus to a susceptible host. Control of the disease is achieved by fungicide, sanitation and, in some cases, quarantine.