Stemphylium solani

Last updated

Stemphylium solani
1234187-PPT.jpg
Stemphylium solani on tomato leaf
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Dothideomycetes
Order: Pleosporales
Family: Pleosporaceae
Genus: Stemphylium
Species:
S. solani
Binomial name
Stemphylium solani
G.F.Weber (1930)

Stemphylium solani is a plant pathogen fungus in the phylum Ascomycota. It is the causal pathogen for grey leaf spot in tomatoes and leaf blight in alliums and cotton, though a wide range of additional species can serve as hosts. Symptoms include white spots on leaves and stems that progress to sunken red or purple lesions and finally leaf necrosis. S. solani reproduces and spreads through the formation of conidia on conidiophores. The teleomorph name of Stemphyllium is Pleospora though there are no naturally known occurrences of sexual reproduction. Resistant varieties of tomato and cotton are common, though the pathogen remains an important disease in Chinese garlic cultivation.

Contents

Hosts and symptoms

Hosts

Darkening lesions on tomato leaves 1234172-PPT.jpg
Darkening lesions on tomato leaves
Advanced necrosis on tomato leaf Stemphylium solani on Tomato leaf.jpg
Advanced necrosis on tomato leaf

Stemphylium solani is of greatest concern in tomatoes, potatoes, peppers, garlic, onions, and cotton, though a wide range of over 20 species have proven susceptible. In tomatoes and potatoes, the resulting disease is known as grey leaf spot. In alliums it is known as leaf blight. Additional hosts are listed below. [1]

Symptoms

In alliums, infection is first visible as oval white spots, 1–3 mm in length, scattered irregularly over the leaf surface. These spots grow into red or purple colored lesions with a yellow margin and finally progress to leaf wilting and necrosis. Experimentally infected plants have been shown to progress from initial infection to leaf necrosis within eight days. Infection is found only on the stems and leaves of plants. [2] In tomatoes, S. solani symptoms begin as round to oval dark specks on both sides of the leaf with older leaves being affected first. Young lesions may have a yellow halo. As lesions age, they become gray, dry and brittle, eventually falling away to create shot-holing in the leaf. Severe infection results in leaf drop. [3]

Disease cycle and morphology

Stemphylium solani is the anamorph stage and reproduces primarily through the production of conidia on conidiophores. Once produced, disease is thought to spread quickly to additional hosts via either mycelium when leaves of adjacent plants are touching or conidia, which can spread through rain or air. S. solani is also believed to be spread via infected seed. [4] Conidia can cause several stages of secondary infection throughout the growing season but infection is most severe following early fruiting. [3] The teleomorph stage of Stemphylium is Pleospora. Sexual ascospores form under cold conditions but natural occurrences have not been documented. [5] Instead, conidia and mycelia overwintering in plant debris are believed to serve as the primary inoculum. [4]

Stemphylium solani grown in potato sugar agar (PSA) culture are characteristically slow growing and darken with age, first to a yellow-brown color after 4 days and then red. Conidiophores grow as long as 170 µm in length with a swollen apex and one to three transverse septa. [1]

Environment

Though minimal data specific to S. solani is available, Stemphyllium spp. thrive in high humidity (relative humidity of 85-90%), more than eight hours of leaf wetness (caused by rain, fog, or dew) and temperatures near 18 °C. Though leaf wetness is important, rainfall per se does not appear necessary if humidity or fog provide sufficient leaf wetness. [1] Presence of debris from the previous season may harbor inoculum and increase disease incidence. Heavy fruiting and good soil fertility also favor disease development. [2]

Management

Stemphylium solani is most commonly controlled with the use of disease resistant cultivars, especially in tomato and cotton. [5] Resistant tomatoes are marked with the code “St”. Varieties include Beefmaster, Better Boy, Celebrity, First Lady II, Floramerica, Jackpot, and Lemon Boy, Amelia, Crown Jewel, FL 47, FL 91, Linda, Phoenix, Quincy, RPT 6153, Sebring, Solar Fire, Soraya, Talledega, Tygress, and many others. [6] [7] Resistance is inherited via the gene Sm, a single dominant gene. [8]

However, resistant cultivars may lack desirable traits, such as a tendency toward early bolting when allium flowers are desirable for markets. When satisfactory resistant cultivars are unavailable, fungicides (tebuconazole, procymidone) can be applied as a seed treatment to provide systemic early season management or as a foliar spray 2-3 times throughout the season. [9] [10] Triazole has been shown in laboratory studies to effectively control mycelial growth and provides local systemic protection. [4] [11] Risk of infection can also be reduced by delaying fall planting of garlic until temperatures fall below the 18 °C optimal for S. solani growth, and good field sanitation. [4]

Importance

With the development of resistant cultivars in of the major crops impacted by this pathogen, the importance of S. solani has been largely mitigated. However, as new strains emerge, continued outbreaks in new crops may continue to cause significant damage and demand a response. For example, the migration of S. solani into the Chinese garlic crop resulted in a 30% average yield loss between 2004 and 2008 with some fields sustaining 70% loss. [12] Similarly, epidemics in cotton have been reported in Brazil and India, resulting in 100% crop loss in India. [13]

Geography

Stemphylium solani is found throughout the world. It was first by described by George Weber in 1930 in Florida, United States. It has since been reported in Brazil, Venezuela, India, South Africa, Spain, Australia, Egypt, and China. [4] [5]

Though 33 species of Stemphylium have been recognized, many are saprophytic. However, S. botryosum, S. globuliferum, S. herbarum, S. alfalfae, and S. vesicarium all cause agricultural damage including leaf spot in alfalfa and red clover, purple spot in asparagus, and leaf spot in garlic and onions. [14] S. veicarium has historically been the causal agent for leaf spot in garlic and onions but since the late 1990s, S. solani has also been shown to be pathogenic to alliums and a significant cause of disease in Chinese garlic crops. Diagnosis of specific species is determined based on distinct conidia and conidiophore morphology, though significant overlap in characteristics makes identification difficult. DNA studies are currently the most conclusive method of correctly distinguishing species of Stemphylium. [12] In addition to other strains of Stemphyllium, symptoms caused by S. solani can also be easily mistaken for Alternaria porri and Septoria Leaf Spot. [1] [2]

Related Research Articles

<span class="mw-page-title-main">White onion</span> Onion cultivar

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 those 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.

<i>Alternaria alternata</i> Pathogenic fungus

Alternaria alternata is a fungus causing leaf spots, rots, and blights on many plant parts, and other diseases. It is an opportunistic pathogen on over 380 host species of plant.

<i>Pseudocercosporella capsellae</i> Species of fungus

Pseudocercosporella capsellae is a plant pathogen infecting crucifers. P. capsellae is the causal pathogen of white leaf spot disease, which is an economically significant disease in global agriculture. P. capsellae has a significant affect on crop yields on agricultural products, such as canola seed and rapeseed. Researchers are working hard to find effective methods of controlling this plant pathogen, using cultural control, genetic resistance, and chemical control practices. Due to its rapidly changing genome, P. capsellae is a rapidly emerging plant pathogen that is beginning to spread globally and affect farmers around the world.

<i>Erysiphe cruciferarum</i> Species of fungus

Erysiphe cruciferarum is a plant pathogen of the family Erysiphaceae, which causes the main powdery mildew of crucifers, including on Brassica crops, such as cauliflower, cabbage, broccoli, and Brussels sprouts. E. cruciferarum is distributed worldwide, and is of particular concentration in continental Europe and the Indian subcontinent. E. cruciferarum is an ascomycete fungus that has both sexual and asexual stages. It is also an obligate parasite that appears to have host specificity; for example, isolates from turnip will not infect Brussels sprout, and vice versa. While being a part of the family Erysiphaceae, it belongs to those members in which the conidia are formed singly and whose haustoria are multilobed.

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 in India in 1962 and still causes significant yield loss to wheat crops on the Indian subcontinent. The disease is caused by a fungal pathogen and causes necrotic leaf lesions and in severe cases shriveling of the leaves.

<i>Leveillula taurica</i> Species of fungus

Leveillula taurica is an obligate fungal pathogen, from the phylum Ascomycota, which causes powdery mildew on onion. This disease prefers warm, dry environments. It is rare in the United States, and is currently restricted to western states. Globally, it is also a minor problem with limited occurrences in the Middle East, Europe, and South America. L. taurica causes powdery mildew of onions, but is also known to infect other allium, solanaceous, and cucurbit species. The disease has appeared in parts of the Middle East, the Mediterranean, and South and North America. Currently, it is not a cause for major concern in the U.S. and throughout the world, as its geographic extent is sparse. In addition, it is relatively easy to control through basic sanitation and reducing water stress.

<i>Ascochyta</i> Genus of fungi

Ascochyta is a genus of ascomycete fungi, containing several species that are pathogenic to plants, particularly cereal crops. The taxonomy of this genus is still incomplete. The genus was first described in 1830 by Marie-Anne Libert, who regarded the spores as minute asci and the cell contents as spherical spores. Numerous revisions to the members of the genus and its description were made for the next several years. Species that are plant pathogenic on cereals include, A. hordei, A. graminea, A. sorghi, A. tritici. Symptoms are usually elliptical spots that are initially chlorotic and later become a necrotic brown. Management includes fungicide applications and sanitation of diseased plant tissue debris.

Alternaria carthami is a necrotrophic plant pathogen of safflower. The fungus is in the order Pleosporales and family Pleosporaceae. It was first isolated in India, has spread globally and can have devastating effects on safflower yield, and resultant oilseed production. A. carthami is known to be seed-borne and appears as irregular brown lesions on safflower leaves and stems.

Alternaria dauci is a plant pathogen. The English name of the disease it incites is "carrot leaf blight".

<i>Alternaria solani</i> Species of fungus

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.

Alternaria helianthi is a fungal plant pathogen causing a disease in sunflowers known as Alternaria blight of sunflower.

This article summarizes different crops, what common fungal problems they have, and how fungicide should be used in order to mitigate damage and crop loss. This page also covers how specific fungal infections affect crops present in the United States.

<span class="mw-page-title-main">Corn grey leaf spot</span> Fungal disease of maize

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.

<span class="mw-page-title-main">Ascochyta diseases of pea</span>

Ascochyta blights occur throughout the world and can be of significant economic importance. Three fungi contribute to the ascochyta blight disease complex of pea. Ascochyta pinodes causes Mycosphaerella blight. Ascochyta pinodella causes Ascochyta foot rot, and Ascochyta pisi causes Ascochyta blight and pod spot. Of the three fungi, Ascochyta pinodes is of the most importance. These diseases are conducive under wet and humid conditions and can cause a yield loss of up to fifty percent if left uncontrolled. The best method to control ascochyta blights of pea is to reduce the amount of primary inoculum through sanitation, crop-rotation, and altering the sowing date. Other methods—chemical control, biological control, and development of resistant varieties—may also be used to effectively control ascochyta diseases.

<span class="mw-page-title-main">Southern corn leaf blight</span> Fungal disease of maize

Southern corn leaf blight (SCLB) is a fungal disease of maize caused by the plant pathogen Bipolaris maydis.

<i>Botrytis allii</i> Species of fungus

Botrytis allii is a plant pathogen, a fungus that causes neck rot in stored onions and related crops. Its teleomorph is unknown, but other species of Botrytis are anamorphs of Botryotinia species. The species was first described scientifically by Mancel Thornton Munn in 1917.

Alternaria black spot of canola or grey leaf spot is an ascomycete fungal disease caused by a group of pathogens including: Alternaria brassicae, A. alternata and A. raphani. This pathogen is characterized by dark, sunken lesions of various size on all parts of the plant, including the leaves, stem, and pods. Its primary economic host is canola. In its early stages it only affects the plants slightly by reducing photosynthesis, however as the plant matures it can cause damage to the seeds and more, reducing oil yield as well.

Cladosporium fulvum is an Ascomycete called Passalora fulva, a non-obligate pathogen that causes the disease on tomatoes 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.

<i>Botrytis squamosa</i> Species of fungus which can damage onion crops

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.

<span class="mw-page-title-main">Alternaria leaf spot</span> Fungal plant disease

Alternaria leaf spot or Alternaria leaf blight are a group of fungal diseases in plants, that have a variety of hosts. The diseases infects common garden plants, such as cabbage, and are caused by several closely related species of fungi. Some of these fungal species target specific plants, while others have been known to target plant families. One commercially relevant plant genus that can be affected by Alternaria Leaf Spot is Brassica, as the cosmetic issues caused by symptomatic lesions can lead to rejection of crops by distributors and buyers. When certain crops such as cauliflower and broccoli are infected, the heads deteriorate and there is a complete loss of marketability. Secondary soft-rotting organisms can infect stored cabbage that has been affected by Alternaria Leaf Spot by entering through symptomatic lesions. Alternaria Leaf Spot diseases that affect Brassica species are caused by the pathogens Alternaria brassicae and Alternaria brassicicola.

References

  1. 1 2 3 4 Lu Zheng et al., “Host Range and Phytotoxicity of Stemphylium Solani, Causing Leaf Blight of Garlic (Allium Sativum) in China,” European Journal of Plant Pathology 124, no. 1 (October 21, 2008): 21–30.
  2. 1 2 3 John P. Damicone and Lynn Brandenberger, “Common Diseases of Tomatoes Part I. Diseases Caused by Fungi” (Oklahoma Cooperative Extension Service, n.d.).
  3. 1 2 L. Cedeño and C. Carrero, “First Report of Tomato Gray Leaf Spot Caused by Stemphylium Solani in the Andes Region of Venezuela,” Plant Disease 81, no. 11 (November 1, 1997): 1332–1332.
  4. 1 2 3 4 5 Lu Zheng et al., “Integrated Control of Garlic Leaf Blight Caused by Stemphylium Solani in China,” Canadian Journal of Plant Pathology 32, no. 2 (June 2, 2010): 135–145.
  5. 1 2 3 Y.R Mehta, “Genetic Diversity Among Isolates of Stemphylium Solani from Cotton.”
  6. ↑ Dennis Pittenger et al., “Growing Tomatoes in the Home Garden” (University of California, 2005)
  7. ↑ Gene McAvoy, “Grower’s IPM Guide for Florida Tomato and Pepper Production - Integrated Pest Management and Florida Tomatoes: A Success Story in Progress” (University of Florida Institute of Food and Agricultural Sciences, January 2008), http://ipm.ifas.ufl.edu/resources/success_stories/T&PGuide/index.shtml.
  8. ↑ Esther Bashi, M. Pilowsky, and J. Rotem, “Resistance in Tomatoes to Stemphylium Floridanum and S. Botryosum F. Sp. Lycopersici,” Phytopathology 63, no. 12 (December 1973): 1542–1544.
  9. ↑ Stemphyllium solani
  10. ↑ Labrinos, J.L, and F.W. Jr Nutter. “Effects of a Protectant Versus a Systemic Fungicide on Disease Components of Peanut Late Leaf Spot.” Plant Disease 77, no. 8 (1993): 837–845.
  11. ↑ Daren Mueller. “Fungicides: Triazoles | Integrated Crop Management.” Integrated Crop Management, November 9, 2006. http://www.ipm.iastate.edu/ipm/icm/2006/5-30/fungicides.html.
  12. 1 2 L. Zheng, J. Huang, and T. Hsiang, “First Report of Leaf Blight of Garlic (Allium Sativum) Caused by Stemphylium Solani in China,” Plant Pathology 57, no. 2 (2008): 380–380.
  13. ↑ Y.R. Mehta, Plant Disease 82 (1998): 333.
  14. ↑ Marcos P. S. Câmara, Nichole R. O’Neill, and Peter van Berkum, “Phylogeny of Stemphylium Spp. Based on ITS and Glyceraldehyde-3-phosphate Dehydrogenase Gene Sequences,” Mycologia 94, no. 4 (August 2002): 660–672.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.