Peronospora hyoscyami f. sp. tabacina. [Descriptions of Fungi and Bacteria].

1989 ◽  
Author(s):  
G. Hall
Keyword(s):  
Geographical Distribution ◽  
Infected Plant ◽  
Weather Conditions ◽  
Plant Diseases ◽  
Plant Tissues ◽  
Airborne Spores ◽  
Distribution Maps ◽  
Blue Mould ◽  
Leaf Spots ◽  
The Usa

Abstract A description is provided for Peronospora hyoscyami f. sp. tabacina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Naturally infected: Capsicum annuum, Nicotiana alpina, N. acuminata, N. attenuata, N. benthamiana, N. bigelowii, N. caesia, N. glauca, N. glutinosa, N. langsdorffi, N. longiflora, N. mesophila, N. nodiflora, N. nudicaulis, N. paniculata, N. quadrivalvis, N. repanda, N. rustica, N.x sanderae, N. stocktoni, N. suavolens, N. sylvestris, N. tabacum, N. tomentosa, N. trigonophylla, N. wigandioides, Solanum lycopersicum, S. melongena, S. nigrum.Infected experimentally: Capsicum frutescens, Dunalia ramiflora, Hyoscyamus muticus, H. niger, Nicotiana alata, N. affnis, N. cavanillesii, N. fragrans, N. gossei, N. goodspeedii, N. ipomopsifolia, N. maritima, N. megalosiphon, N. raimondii, N. tomentosifolius, Lehmania otophora, Physalis alkekangi, P. lanceifolia, P. peruviana, Petunia × hybrida, Schizanthus pinnatus. DISEASE: Blue mould of tobacco plants (48, 3141; 61, 2664) (commercial and ornamental varieties are affected); the fungus is an obligately biotrophic plant pathogen. Chlorotic leaf spots develop on leaves of susceptible seedlings, which become deformed. Undersurfaces of leaves become covered with a layer of sporophores, producing a diagnostic blue-grey felt. Rapid generalized light-brown tissue necrosis follows and the apical meristem ceases growth. Disease symptoms may not appear immediately after infection, however, or during sporophore production. If the fungus encounters any barrier to its growth through the plant tissues (because of a physiological response, high temperature or fungicides), then the infection becomes wholly systemic, being confined to an area close to the veins, or to a necrotic area if the plant is genetically resistant. Similar symptoms develop on mature plants in the field and the entire plant may be destroyed within 3-4 weeks, leaving only a blackened stem. The fungus attacks leaves and stems of tobacco seedlings and mature plants in Europe and Australia, but only leaf tissues in the USA, where weather conditions confine it to being a seedling disease in most years. GEOGRAPHICAL DISTRIBUTION: First reported in Australia in 1891, now worldwide; see CMI Distribution Maps of Plant Diseases 23. TRANSMISSION: By airborne spores, which can remain viable for 2 months at 20-40% RH, and have been reported to be transported over distances of 1, 600 km. Most favourable conditions for sporulation are an average temperature of 20°C and a period of relatively high humidity (95% RH) for at least 3 h. Spore liberation is dependent on a rise in temperature, a decrease in relative humidity and an increase in insolation. There is some evidence for soil-borne transmission by oospores in infected plant debris in the USA, since blue mould appears more often in seedbeds which have previously contained infected tobacco. Although mycelium can survive and overwinter in plant tissues, there are no reports of transmission by a systemic route.

Septoria antirrhini. [Descriptions of Fungi and Bacteria].

2004 ◽  
Author(s):  
T. V. Andrianova
Keyword(s):  
South Africa ◽  
Czech Republic ◽  
New Zealand ◽  
Great Britain ◽  
South America ◽  
Geographical Distribution ◽  
Infected Plant ◽  
Weather Conditions ◽  
Plant Debris ◽  
Wet Weather

Abstract A description is provided for Septoria antirrhini. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Leaf spot, leaf drying, defoliation. HOSTS: Antirrhinum antirrhiniflorum, A. majus, A. siculum (Scrophulariaceae). GEOGRAPHICAL DISTRIBUTION: AFRICA: South Africa. NORTH AMERICA: Canada, USA. SOUTH AMERICA: Chile, Colombia. ASIA: Armenia, Azerbaijan, China, Iran, Israel. AUSTRALASIA: Australia, New Zealand. EUROPE: Bulgaria, Czech Republic, Estonia, France, Germany, Great Britain, Hungary, Ireland, Italy, Netherlands, Portugal, Romania, Ukraine, former Yugoslavia. TRANSMISSION: Not reported, but almost certainly by airborne, splash-dispersed conidia from infected plant debris and seed stocks. The disease is significantly more severe under wet weather conditions (SINADSKIY et al., 1985).

Passalora sojina. [Descriptions of Fungi and Bacteria].

2004 ◽  
Author(s):  
J. C. David
Keyword(s):  
New York ◽  
South Carolina ◽  
Geographical Distribution ◽  
Far East ◽  
Uttar Pradesh ◽  
Plant Diseases ◽  
Mato Grosso ◽  
Distribution Maps ◽  
Aerial Dispersal ◽  
Dead Plant

Abstract A description is provided for Passalora sojina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Frog-eye leafspot. HOSTS: Glycine hispida, G. javanica, G. max, G. soja, G. ussuriensis (FALEEVA, 1976), Mucuna sp. (CROUS & BRAUN, 2003) (Fabaceae). GEOGRAPHICAL DISTRIBUTION: [CAB International Distribution Maps of Plant Diseases No. 871, Edn. 1 (2002)]. AFRICA: Cameroon, Côte d'Ivoire, Egypt, Gabon, Kenya, Malawi, Nigeria, Zambia, Zimbabwe. NORTH AMERICA: Canada (Ontario), Mexico, USA (Alabama, Arkansas, Delaware, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Louisiana, Maryland, Michigan, Mississippi, Missouri, New Jersey, New York, North Carolina, Oklahoma, South Carolina, Texas, Virginia, West Virginia, Wisconsin). CENTRAL AMERICA: Cuba, Guatemala. SOUTH AMERICA: Argentina, Bolivia, Brazil (Goias, Maranhao, Mato Grosso, Minas Gerais, Parana, Pernambuco, Piaui, Rio Grande do Sul, Santa Catarina, Sao Paolo), Venezuela. ASIA: China (Fujian, Gansu, Guangxi, Hebei, Heilongjiang, Henan, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Menggu, Sichuan, Yunnan, Zhejiang), East Timor, India (Karnataka, Meghalaya, Sikkim, Uttar Pradesh), Japan, Nepal, Russia (Far East), South Korea, Taiwan. EUROPE: Russia. TRANSMISSION: Seedborne and by aerial dispersal of conidia through wind and rain splash. The fungus also survives in dead plant material and can re-infect living plants (SWEETS, 2001).

Sclerotinia narcissicola. [Descriptions of Fungi and Bacteria].

1991 ◽  
Author(s):  
M. A. J. Williams
Keyword(s):  
New York ◽  
North Carolina ◽  
Geographical Distribution ◽  
Grey Mould ◽  
Ground Level ◽  
Plant Diseases ◽  
West Germany ◽  
Distribution Maps ◽  
Detached Leaves

Abstract A description is provided for Sclerotinia narcissicola. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Narcissus spp. DISEASE: Smoulder, grey mould. Infection may reduce bulb yield and flower size (55, 3617). Symptoms may include: rot of the bulbs and leaves at ground level, brown lesions on the leaves and flower buds, distortion and failure of emergence. GEOGRAPHICAL DISTRIBUTION: Asia: Iraq, USSR; Australasia: Australia (Tasmania, Victoria), New Zealand; Europe: Channel Islands (Guernsey, Jersey), Denmark, Eire, England, Germany, Northern Ireland, The Netherlands, Norway, Scotland, Sweden, USSR, Wales, West Germany; North America: Canada (British Columbia, NS, Ontario, PEI); USA (North Carolina, New York, Oregon, Virginia, Washington State) (see CMI Distribution Maps of Plant Diseases, No. 315). TRANSMISSION: The disease may come from planting of infected bulbs or from infected soil; sclerotia in the soil may be viable for up to nine months (61, 7053). In vitro conidial suspensions did not cause infection except of wounded or damaged tissue; mycelial inoculation consistently caused lesions on detached leaves and bulb scales (61, 5797).

Valsa sordida. [Descriptions of Fungi and Bacteria].

1998 ◽  
Author(s):  
V. P. Hayova
Keyword(s):  
Czech Republic ◽  
New Zealand ◽  
North America ◽  
South America ◽  
Environmental Stress ◽  
Geographical Distribution ◽  
Plant Diseases ◽  
Republic Of Georgia ◽  
Distribution Maps ◽  
Poplar Trees

Abstract A description is provided for Valsa sordida. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Valsa sordida is usually associated with Valsa canker of poplar twigs. Wounded trees, and trees injured by insects or attacked by other pathogens are more susceptible to infection. Development of Valsa canker is affected by environmental stress (Guyon, 1996; Tao et al., 1984). Poplar canker caused by V. sordida has been studied in different countries (CMI Distribution Maps of Plant Diseases, 1977; Worrall, 1983; Wang et al., 1981) The fungus can be often found in declining poplar stands together with another pathogen of poplar trees, Leucostoma niveum. Valsa sordida may also cause necrosis of willow twigs. HOSTS: Populus spp., Salix spp. and, more rarely, other woody angiosperms. GEOGRAPHICAL DISTRIBUTION: Africa: Morocco. Asia: Armenia, Azerbaijan, China, Republic of Georgia, India, Iran, Iraq, Israel, Japan. Kazakhstan, Korea, Russia (Tatarstan), Turkey, Turkmenia, Uzbekistan. Australasia: Australia (Victoria), New Zealand. Europe: Austria, Belgium, Bulgaria, Czech Republic, Denmark, Estonia, France, Germany, Greece, Ireland, Italy, Netherlands, Norway, Poland, Portugal, Rumania, Russia, Slovakia, Sweden, Switzerland, UK, Ukraine, former Yugoslavia. North America: Canada (Alberta, British Columbia, Nova Scotia, Ontario, Québec, Saskatchewan). USA (California, Colorado, Michigan, Minnesota). South America: Chile. TRANSMISSION: Both conidia and ascospores are air-borne, especially under humid conditions. Yellow or orange exudation of conidia from conidiomata can be often seen after rain.

scholarly journals Leaf Spot Caused by Alternaria sp. on Iberis sempervirens in Italy

Plant Disease ◽  
2005 ◽  
Vol 89 (11) ◽  
pp. 1243-1243 ◽  
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
M. L. Gullino
Keyword(s):  
Leaf Spot ◽  
Single Cells ◽  
Morphological Characteristics ◽  
Weather Conditions ◽  
The United States ◽  
Plant Diseases ◽  
Pathogenicity Test ◽  
Aesthetic Quality ◽  
Leaf Spots ◽  
Alternaria Sp

Iberis sempervirens (candytuft) is increasingly grown in Liguria (northern Italy) as a potted plant for ornamental purposes, particularly under cool-weather conditions. At the end of the summer of 2003, extensive necrosis was observed on leaves and young stems of 4-month-old plants grown in 14-cm diameter pots outdoors at a commercial farm. In many cases, on the upper side of the leaves, necrotic spots were surrounded by a chlorotic halo that turned progressively black. The necrotic areas often coalesced, generating larger and irregularly shaped spots. On the lower side of the leaves, no chlorotic areas were observed. Severely affected plants were defoliated. Infected plants rarely died, but the presence of lesions on mature plants decreased aesthetic quality and subsequently market value. The disease occurred on 40% of plants at each of the two farms. Leaf spots contained dark brown, multicellular pear-shaped conidia. Conidia were 22.5 to 50.0 μm (average 32.8 μm) long and 7.5 to 15.0 μm (average 12.3 μm) wide, with 5 to 7 longitudinal cross walls and an average of 6 to 7 single cells. From infected leaves, a fungus identified on the basis of its morphological characteristics as Alternaria sp. was consistently isolated on potato dextrose agar. Pathogenicity tests were performed by spraying leaves of healthy 12-month-old potted I. sempervirens plants with a spore and mycelial suspension (105 CFU/ml). Plants without inoculation served as control. Ten plants were used for each treatment. Plants were covered with plastic bags for 10 days after inoculation and kept outdoors for 60 days at temperatures ranging from 0 to 32°C (average 12°C). The first lesions developed on leaves 45 days after inoculation, while control plants remained healthy. From such lesions, Alternaria sp. was consistently reisolated. The pathogenicity test was carried out twice. The presence of A. brassicae was reported in Tanganica on Iberis sp., I. umbellata in Denmark (2), and I. amara in the United States (4); A. matthiolae was observed on seeds of I. amara and I. umbellata (3). A leaf spot incited by Alternaria sp. on I. amara was observed in Florida (1). This is, to our knowledge, the first report of Alternaria sp. on I. sempervirens in Italy as well as worldwide. References: (1) S. A. Alfieri et al. Index of Plant Diseases in Florida. Bull. 11, 1984. (2) P. Neergaard. Rev. Appl. Micol. 18:572, 1939. (3) P. Neergaard. Rev. Appl. Micol. 25:382, 1946). (4) R. D. Raabe. Comb. Proc. Int. Plant Propagators Soc. 40:160, 1991.

Sporisorium sorghi. [Descriptions of Fungi and Bacteria].

2002 ◽  
Author(s):  
J. M. Pérez
Keyword(s):  
Sorghum Bicolor ◽  
Central America ◽  
Geographical Distribution ◽  
Plant Diseases ◽  
Panicum Miliaceum ◽  
Distribution Maps ◽  
Infected Seed

Abstract A description is provided for Sporisorium sorghi. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Covered smut or covered kernel smut of sorghum. Development of functional ovaries and anthers is prevented in infected parts of the plants. HOSTS: Panicum miliaceum, Sorghum bicolor, S. dochna, S. halepense, S. plumosum, S. sudanense and S. vulgare (Poaceae). This species has also been recorded from Ischaemum ciliare (VISWANATHAN et al., 2000). GEOGRAPHICAL DISTRIBUTION: Worldwide, see CMI Distribution Maps of Plant Diseases No. 220, edn 4 (1987). In addition it has been recorded from AFRICA: Mauritania (FRISON & SADIO, 1987). CENTRAL AMERICA: Nevis. TRANSMISSION: In addition to dissemination on infected seed, there is evidence that this species can also be spread by air-borne chlamydospores (SHENOI & RAMALINGAM, 1976).

Septoria lepidii. [Descriptions of Fungi and Bacteria].

1999 ◽  
Author(s):  
T. V. Andrianova
Keyword(s):  
North America ◽  
Geographical Distribution ◽  
Infected Plant ◽  
West Siberia ◽  
Former Yugoslavia ◽  
Republic Of Georgia ◽  
Plant Debris ◽  
Type Host ◽  
Leaf Spots

Abstract A description is provided for Septoria lepidii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Leaf mortality. Clearly-defined leaf spots are not produced. Instead the whole leaf becomes discolored, turning pale brown or fawn, with the discoloration spreading from infection sites. Conidiomata are then produced as the whole leaf dies. HOSTS: Cardaria draba, C. propinqua, C. pubescens, C. repens (syn. : Lepidium repens), Lepidium affine, L. campestre, L. heterophyllum, L. latifolium, L. officinale, L. perfoliatum, L. sativum, L. sibiricum, L. smithii, L. vesicatorium (Brassicaceae). [Type host -L. heterophyllum.] GEOGRAPHICAL DISTRIBUTION: Asia: Armenia, Azerbaijan, Republic of Georgia, Iran, Kazakhstan, Kirghizistan, Russia (West Siberia), Tadzhikistan, Turkmenistan, Uzbekistan. Europe: Austria, Belgium, Denmark, Estonia, France, Germany, Ireland, Italy, Hungary, Moldova, Netherlands, Portugal, Romania, Russia, Spain, UK, Ukraine, former Yugoslavia. North America: USA. TRANSMISSION: Not reported, but almost certainly by air-borne or splash dispersed conidia, also from infected plant débris.

scholarly journals Definition of Tissue-Specific and General Requirements for Plant Infection in a Phytopathogenic Fungus

2001 ◽  
Vol 14 (3) ◽  
pp. 300-307 ◽  
Author(s):  
Marie Dufresne ◽  
Anne E. Osbourn
Keyword(s):  
Map Kinase ◽  
Magnaporthe Grisea ◽  
Plant Diseases ◽  
Gaeumannomyces Graminis ◽  
Phytopathogenic Fungus ◽  
Plant Tissues ◽  
Leaf Blast ◽  
Tissue Specific ◽  
Leaf Spots ◽  
Plant Infection

Although plant diseases are usually characterized by the part of the plant that is affected (e.g., leaf spots, root rots, wilts), surprisingly little is known about the factors that condition the ability of pathogens to colonize different plant tissues. Here we demonstrate that the leaf blast pathogen Magnaporthe grisea also can infect plant roots, and we exploit this finding to distinguish tissue-specific and general requirements for plant infection. Tests of a M. grisea mutant collection identified some mutants that were defective specifically in infection of either leaves or roots, and others such as the map kinase mutant pmk1 that were generally defective in pathogenicity. Conservation of a functional PMK1-related MAP kinase in the root pathogen Gaeumannomyces graminis was also demonstrated. Exploitation of the ability of M. grisea to infect distinct plant tissues thus represents a powerful tool for the comprehensive dissection of genetic determinants of tissue specificity and global requirements for plant infection.

Plasmopara halstedii. [Descriptions of Fungi and Bacteria].

1989 ◽  
Author(s):  
G. Hall
Keyword(s):  
Geographical Distribution ◽  
Latent Infection ◽  
Secondary Infection ◽  
Root Hairs ◽  
Systemic Infection ◽  
Plant Diseases ◽  
Plasmopara Halstedii ◽  
Distribution Maps ◽  
Wide Range ◽  
Putative Origin

Abstract A description is provided for Plasmopara halstedii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Over 80 hosts from a wide range of genera in the Compositae have been reported, including wild and cultivated species of Helianthus. For lists see Leppik (1966) and Novotel'nova (1977). DISEASE: Downy mildew of sunflower (Helianthus annuus var. macrocarpus); the fungus is an obligately biotrophic plant pathogen. Leaves of infected plants develop chlorotic mottling which spreads from the veins near the petiole across the lamina, and increases in area and intensity as leaves age. Plants become stunted, having thin stems, very much smaller capitula without seeds, and smaller and darker roots. The disease is primarily systemic and mycelium can be found throughout the plant from roots to capitulum and achenes, in all except meristematic tissues. Under humid conditions, a white felt of sporangiophores develops on the undersurface of chlorotic areas. Localized secondary infection of the leaves and heads occasionally develops, resulting in spots, delimited by veins. Such secondary infection may also become systemic. Some infected plants show no disease symptoms, but produce lower yields of poorer quality seeds, which lose vitality and have lower germination rates (latent infection). Cotyledons are also infected causing damping-off in seed beds. A basal gall may also be produced. GEOGRAPHICAL DISTRIBUTION: Plasmopara halstedii is a fungus characteristic of the Americas, its putative origin, It has spread throughout Europe to parts of Africa and Asia, and has recently been reported from New Zealand. See CMI Distribution Maps of Plant Diseases 286. TRANSMISSION: Soil-borne oospores and mycelium (in systemically infected roots) overwinter, infecting subsequent crops. Sporangia form on the surface of infected seedling roots, releasing zoospores which encyst and germinate c root hairs of other seedlings, producing a systemic infection. Sporangia are dispersed by rain-splash from leaves, producing a secondary infection in plants up to the six-leaf stage, but infect only the apical growing points of olde plants. Transmission by oospores in seeds has been responsible for the spread of this fungus around the world, especially since these spores can germinate to produce only a latent infection in the host plant (53, 4545).

Peronospora rubi. [Descriptions of Fungi and Bacteria].

1989 ◽  
Author(s):  
G. Hall
Keyword(s):  
New Zealand ◽  
North America ◽  
Downy Mildew ◽  
Geographical Distribution ◽  
Systemic Disease ◽  
Interspecific Cross ◽  
Plant Diseases ◽  
Red Raspberry ◽  
Outer Cortex ◽  
Distribution Maps

Abstract A description is provided for Peronospora rubi. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Rubus arcticus, R. caesius, R. canadensis, R. canescens, R. chamaemorus, R. cissiburiensis, R. cissoides, R. corylifolius egg. (R. caesius × tereticaulis, R. nemorosus), R. flagellaris, R. fruticosus egg. (R. bregutiensis, R. buschi, R. glandulosus, R. hirtus, R. menkei, R. seebergensis, R. tereticaulis, R. vulgaris), R. idaeus, R. laciniatus, R. leucodermis, R. × loganobaccus (orursinus × ideaus), R. occidentalis, R. parviflorus, R. plicatus, R. procerus, R. spectabilis, R. strigosus, R. sulcatus, R. tuberculatus, R. villosus, R. vitifolius, and certain hybrids, e.g. 'Tayberry' (blackberry cv. Aurora × tetraploid red raspberry), 'Tummelberry' (a 'Tayberry' interspecific cross) and 'Youngberry'. DISEASE: Downy mildew of cane fruits (Rubus spp.), especially blackberry (R. fruticosus agg.), boysenberry (a blackberry × red raspberry cross: the name R. × loganobaccus covers this plant) and raspberry (R. idaeus). The fungus, an obligately biotrophic plant pathogen, occurs on leaves in summer to autumn, producing small, conspicuous, irregularly shaped patches on upper leaf surfaces, starting near the petiole, then following leaf veins. Patches are initially yellow, becoming carmine-red, vinaceous or purple and are bordered by venation. The undersurface of the leaf shows only a pale area with a brownish edge, and brownish discoloration near and alongside veins. Sporophores are sometimes difficult to detect in the dense mat of leaf hairs, but are heaviest on lowest leaves, close to ground level, forming a buff-grey felt. In wild-growing European species of Rubus the fungus occurs exclusively on the leaves. In North America it attacks leaves of cultivated raspberry bushes, and in New Zealand the fruits, sepals and pedicels of boysenberry, causing the fruit to become dry and shrivelled (dryberry disease). Downy mildew has recently become a problem on certain berry cultivars in Eastern England (McKeown, 1988). GEOGRAPHICAL DISTRIBUTION: Africa: South Africa. Asia: USSR (Azerbaijan). Australasia & Oceania: New Zealand. Europe: Czechoslovakia, Denmark, Finland, France, Germany (GFR, GDR), Norway, Poland, Rumania, Sweden, Switzerland, United Kingdom, USSR (Latvia). North America: Canada (British Columbia), USA (IL, MD, OR, WA, WI). See CMI Distribution Maps of Plant Diseases 598. TRANSMISSION: Determined for boysenberry in New Zealand only (61, 4245), where it is a systemic disease confined to the outer cortex parenchyma, keeping pace with cell division at apical meristems. Systemic cane infection is often indicated by red streaking of stems and petioles linking successively diseased leaves on a shoot. Unfolding leaves are invaded during warm wet weather causing typical leaf symtoms. Stores produced on diseased shoots initiate secondary infections of flowers and developing berries. These berries then become an important source of inoculum for new cycles of the disease. They go largely unnoticed, since spores are partially hidden on the split berry surfaces or covered by the sepals. After harvest, infection of developing primocanes continues by internal mycelial growth and spore infection. Oospores form on root surfaces in dead cortex cells and leaves. Soilborne oospores may infect healthy plants established in former sites of infected root crowns.

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