Pythium dissotocum. [Descriptions of Fungi and Bacteria].

Author(s):  
M. A. Spencer

Abstract A description is provided for Pythium dissotocum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASES: Root-rot, seedling damping-off; necrotrophic or parasitic on fishes. HOSTS: Daucus carota (Apiaceae); Lactuca sativa, Parthenium argentatum (Asteraceae); Beta vulgaris, Spinacea oleracea (Chenopodiaceae); Cucumis sativus (Cucurbitaceae); Kummerowia stipulacea, Lupinus digitatus, L. polyphyllus, Medicago sativa, Phaseolus vulgaris, Pisum sativum, Vicia faba (Fabaceae); Pelargonium cv. (Geraniaceae); Hydrilla verticillata (Hydrocharitaceae); Iris sp. (Iridaceae); Garya illinoensis (Juglandaceae); Hyacinthus cv., Tulipa cv. (Liliaceae s.l.); Papaver somniferum (Papaveraceae); Oryza sativa, Saccharum officinarum, Triticum aestivum (Poaceae); Fragaria × ananassa, F. vesca, Prunus persica (Rosaceae); Citrus nobilis (Rutaceae); Capsicum annuum, Lycopersicon esculentum (Solanaceae); Pilea pumila (Urticaceae). Neogobius fluviatilis, Neogobius gymnotrachelus, Perccottus glenii, Pseudorasbora parva (Pisces). GEOGRAPHICAL DISTRIBUTION: AFRICA: South Africa. NORTH AMERICA: Canada, USA (Arizona, Colorado, Louisiana, Missouri, Pennsylvania, Wisconsin). ASIA: China, India, Indonesia (Sabah), Japan, Korea, Lebanon, Russia. AUSTRALASIA: Australia (Queensland). EUROPE: Great Britain, Iceland, Netherlands. TRANSMISSION: Contaminated soil, organic matter (oospores) and water (sporangia).

Author(s):  
G. Hall

Abstract A description is provided for Aphanomyces cladogamus. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Capsicum sp., Lactuca saliva, Linum sp., Lycopersicon esculenteum, Raphanus sativus, Solanum melongena, Spinacea oleracea, Viola tricolor. DISEASE: Root rot of pepper, spinach, pansy, tomato and several other crop and garden plants. The fungus, a facultatively necrotrophic plant pathogen, attacks seeds (pre-emergence disease) and/or seedlings (post-emergence damping off). Affected plants develop a generalized wilt which becomes progressively more severe. In pepper, seeds are attacked and black lesions develop on hypocotyls of the surviving seedlings, often extending to the bases of the cotyledons (32, 360). In spinach, roots become covered in yellow to orange spots their tissues becoming soft and water-soaked. In pansies, the vascular cylinder develops a deep orange-reddish discoloration in which, in the early stages of infection, numerous oospores can be seen. Stem bases become extensively rotted and eventually the aerial organs collapse and shrivel (13, 379; 34, 370). In tomato plants, rootlet tips become discoloured and die back (6, 517). GEOGRAPHICAL DISTRIBUTION: Europe: Sweden. North America: Canada (Ontario), USA (MD, NC, NJ, VA, WA, WI). See CMI Distribution Maps of Plants Diseases 601. TRANSMISSION: Not reported. Presumably by zoospores and oogonia remaining in infected tissues. As the fungus appears to infect a wide range of plants, it may persist in the roots of weeds.


Author(s):  
G. M. Waterhouse

Abstract A description is provided for Pythium mamillatum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Ageratum houstonianum, Agrostis stotonifera, Allium cepa, Ananas comosus, Antirrhinum majus, Aquilegia caerulea, Avena sativa, Beta vulgaris, Brassica nigra, B. oleracea, Citrullus vulgaris, Collinsia bicolor, Cucumis sativus, Festuca duriuscula, Geum chiloense, Gossypium sp., Linum usitatissimum, Medicago sativa, Papaver somniferum, Pelargonium spp., Pisum sativum, Saccharum officinarum, Triticum aestivum, Viola tricolor and in soil. Also on algae (Cladophora sp., Glorocapsa sp.) on inoculation. DISEASE: Causes damping-off of seedlings and root rot of various hosts including the following crops, cauliflower, cotton, cocumber, flax, lucerne, mustard, oats, onion, pineapple, sugar beet, sugarcane and wheat. GEOGRAPHICAL DISTRIBUTION: Africa (Central African Republic); Australasia & Oceania (Australia, Hawaii); Europe (Germany, Great Britain, Netherlands, Sweden); North America (U.S.A.). TRANSMISSION: Soil-borne. Abundant in sandy nursery soils (44, 52). The pathogen has a restricted role as a pioneer colonizer of cultivated soil, surviving in organic matter as hyphal resting bodies (Barton, 1961). Oospore germination in response to exudates from living seedlings has also been demonstrated (Barton, 1957).


Author(s):  
M. A. Spencer

Abstract A description is provided for Pythium heterothallicum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASES: Seedling damping-off. HOSTS: Sambucus sp. (Caprifoliaceae); Spinacea oleracea (Chenopodiaceae); Lens culinaris (Fabaceae); Pelargonium cv. (Geraniaceae); Triticum aestivum (Poaceae); Malus domestica[Malus pumila] (Rosaceae). GEOGRAPHICAL DISTRIBUTION: AFRICA: Kenya. NORTH AMERICA: Canada, USA (Idaho, Washington). CENTRAL AMERICA: Costa Rica. AUSTRALASIA: New Zealand. EUROPE: Czech Republic, Germany, Great Britain, Netherlands, Slovak Republic, Spain, Sweden. TRANSMISSION: Contaminated soil, organic matter (oospores) and water (sporangia).


Author(s):  
G. M. Waterhouse

Abstract A description is provided for Pythium intermedium. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a wide range of hosts represented by the following families: Begoniaceae, Bromeliaceae, Chenopodiaceae, Compositae, Coniferae, Cruciferae, Euphorbiaceae, Geraniaceae, Gramineae, Leguminosae, Liliaceae, Linaceae, Moraceae, Onagraceae, Ranunculaceae, Rosaceae, Solanaceae, Ulmaceae, Violaceae; also in the Equisetales and Filicales. DISEASES: Damping-off of seedlings, foot rot and root rot of ornamentals, occasionally of crop plants and trees. GEOGRAPHICAL DISTRIBUTION: Asia (China); Australia & Oceania (Hawaii); Europe (England, Belgium, France, Germany, Holland, Sweden, U.S.S.R.); North America (U.S.A.); South America (Argentina). TRANSMISSION: A common soil inhabitant.


Author(s):  
P. W. Crous

Abstract A description is provided for Calonectria scoparia. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Acacia spp. (68, 1566), Araucaria heterophylla, Eucalyptus spp., Fragaria sp., Luma sp., Medicago sativa, M. truncatula, Persea americana, Pinus spp., Pisum sativum, Rhododendron spp., Prunus sp., Syncarpia gummifera. DISEASE: Damping off, root rot, cutting rot, stem cankers, leaf spotting, seedling and shoot blight. GEOGRAPHICAL DISTRIBUTION: Australia, Brazil, India, Kenya, Mauritius, South Africa. TRANSMISSION: Wind and splash dispersal.


Author(s):  
G. M. Waterhouse

Abstract A description is provided for Pythium deliense. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Hibiscus esculentus, Lycopersicon esculentum, Nicotiana tabacum and Saccharum officinarum. Also on Capsicum annuum, Carica papaya, Cucumis sativus, Cucurbita pepo, Datura fastuosa, Petunia sp. and Solanum melongena on inoculation (Rangaswami, 1959; Herb. IMI). DISEASE: Causing damping-off of tomato seedlings, stem-burn of tobacco and fruit rot of okra. GEOGRAPHICAL DISTRIBUTION: Asia (Indonesia, Sumatra) and Australasia & Oceania (Australia, New Guinea, Papua); North America (? United States); Central America & West Indies (? N˜caragua). TRANSMISSION: Soil-borne.


Author(s):  
G. M. Waterhouse

Abstract A description is provided for Pythium graminicola. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Agropyron cristatum, Avena saliva, Bromus inermis, Hordeum vulgare, Oryza saliva, Panicum miliaceum, Phleum pratense, Saccharum officinarum, Secale cereale, Setaria glauca, Sorghum vulgare, Triticum aestivum, Zea mays. DISEASE: Seedling blight, collar and root rot of wheat, maize, sugar-cane, and other Gramineae. GEOGRAPHICAL DISTRIBUTION: Africa (Mauritius, South Africa, Sudan); Asia (Ceylon, India, Indonesia, Malaya, Philippines, Taiwan); Australasia & Oceania (Australia, Hawaii); Europe (England, France, Italy); North America (Canada, Mexico, U.S.A.); Central America & West Indies (British Honduras, Jamaica, Puerto Rico, Salvador); South America (Argentina). (CMI Map 296) TRANSMISSION: Soil-borne. Most prevalent at depth of 3-6 in. and infrequent at 27-30 in. (38: 396), surviving in soil as oospores whose germination is stimulated by contact with growing roots of gramineous plants. Host roots may thus be used as traps for isolating the pathogen from the soil (37: 649; 41: 583).


Author(s):  
A. Peerally

Abstract A description is provided for Calonectria kyotensis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Acacia dealbata, Camellia sinensis, Dianthus barbatus, Pinus sp., Prunus persica, Rhododendron (Azalea) and Syringa vulgaris. DISEASE: Causes a root rot of peach trees and in inoculation tests was found to cause wilting, root rot and death of peach seedlings (46, 2468). Severe losses to cuttings and liners of azaleas, lilac and Sweet William reported (47, 3461). Associated with Cylindrocladium scoparium with 'short life' of peach trees (51, 1648), C. floridanum being usually more virulent. Causes death of single-node tea cuttings in Mauritius (52, 1249) and associated with decline of tea bushes (Peerally, 1972). Soil drenches with benomyl give complete control of the pathogen (47, 3461). Soil drenches with benomyl and dithane M-45, and manuring with artificial fertilizers followed by earthing up, have given satisfactory control of root rot of tea bushes in Mauritius. GEOGRAPHICAL DISTRIBUTION: England, Germany, Japan, Mauritius and USA. TRANSMISSION: The pathogen is soil-inhabiting, rarely attacking aerial parts of plants.


Author(s):  
D. J. Stamps

Abstract A description is provided for Phytophthora palmivora. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: A wide range; 138 species of economic, ornamental, shade and hedge plants were listed (48, 337-344). DISEASE: Black pod and canker of cacao; patch canker, black stripe and leaf fall of Hevea rubber; bud rot of coconut and other palms; fruit and stem rot of pawpaw; root rots and damping-off of seedlings. GEOGRAPHICAL DISTRIBUTION: World-wide in tropical and warm temperature regions with high rainfall. TRANSMISSION: In cacao by direct contact between diseased and healthy pods, by rain splash from diseased pods, leaves and infested soil, and by insect vectors and ant tents. In rubber by rain. Soil as a source of inoculum for pawpaw root rot.


Author(s):  
C. Booth

Abstract A description is provided for Cylindrocladium scoparium. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: A very wide host range, mainly of woody plants, including conifers, but also extending to beet, strawberry and watermelon. Particularly notable as a pathogen of young eucalyptus and pine. DISEASE: Damping-off, seedling root-rot, seedling blight. GEOGRAPHICAL DISTRIBUTION: Worldwide, including North America (USA, Canada), South America (Brazil, Argentina), West Indies (Jamaica), Australia and New Zealand, Asia (India, Japan, Malaysia), Africa. TRANSMISSION: By microsclerotia and infected debris in the soil and by airborne, splash-dispersed conidia.


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