Peronospora sparsa. [Descriptions of Fungi and Bacteria].

1981 ◽  
Author(s):  
S. M. Francis
Keyword(s):  
Downy Mildew ◽  
Geographical Distribution ◽  
Disease Transmission ◽  
Unknown Origin ◽  
Northern Europe ◽  
Flower Buds ◽  
Rosa Canina ◽  
Necrotic Spots ◽  
One Year

Abstract A description is provided for Peronospora sparsa. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Cultivated roses and the following species, Rosa californica, R. centifolia, R. canina, R. chinensis, R. rubiginosa. DISEASE: Downy mildew of rose. Bright red to purple or, less frequently, brown spots develop on the leaves which fall very readily especially if the bushes are shaken gently. A non-parasitic defoliation of unknown origin termed a 'false mildew' has been reported from France (Tramier, 1962). The necrotic spots formed on the leaves are similar at a certain stage to those caused by P. sparsa. Conidiophores and conidia develop on the under surface of the downy mildew spots in high relative humidity. In Europe their production is sparse but in California it is reported as copious (Baker, 1953). In heavy infections stems and flowers (both calyx and petals) become diseased and badly infected and young stems often die back. Flowers and flower buds can be retarded and malformed by the pathogen without visible damage to the leaves (53, 3523). GEOGRAPHICAL DISTRIBUTION: Africa (Egypt, Morocco, S. Africa, Zimbabwe); Asia (Brunei, Iran, Israel, Japan, Mauritius, Philippines); Australasia (Australia, New Zealand); Europe (Austria, Britain (incl. Jersey), Bulgaria, Czechoslovakia, Estonia, France, Germany, Greece, Iceland, Italy, Latvia, Netherlands, Portugal, Poland, Romania, Sweden, Switzerland, Yugoslavia, USSR); N. America (Canada, USA); S. America (Argentina, Brazil). TRANSMISSION: As dormant mycelium in cuttings and plants. It is reported that mycelium can overwinter within infected stems both from warmer countries such as Australia (57, 2154) and Brazil (19, 98) and also from Northern Europe (53, 3523). The role of oospores in disease transmission is less certain. They have been found in leaves and stems (Baker, 1953; Fraymouth, 1956) and flowers (Cuboni, 1888) but their occurrence seems to be sporadic and they do not appear to be of great importance in carrying over the pathogen. The possibility that the disease may be seed borne was suggested by a worker in Poland (7, 325). In 1926 downy mildew was discovered in a commercial nursery near Lublin on one-year-old seedlings of Rosa canina. The seedlings had been raised from seed imported from Vienna and the inference was that the disease came with the seed especially as all seedlings of local origin were healthy. Peronospora sparsa is not listed as a seed pathogen by Neergaard (1977).

Peronospora oerteliana. [Descriptions of Fungi and Bacteria].

1994 ◽  
Author(s):  
G. Hall
Keyword(s):  
Downy Mildew ◽  
Geographical Distribution ◽  
Disease Transmission ◽  
Rain Splash

Abstract A description is provided for Peronospora oerteliana. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Primula acaulis, P. algida, P. elatior, P. juliae, P. officinalis, P. veris, P. vulgaris. DISEASE: Downy mildew of Primula species. GEOGRAPHICAL DISTRIBUTION: Asia-Temperate: Kazakhstan. Europe: Czechoslovakia, Denmark, Eire, France, Germany, Poland, Romania, Sweden, Switzerland, Yugoslavia, UK (England, Scotland). TRANSMISSION: By conidia which are dispersed by wind or rain-splash. The role of oospores in disease transmission is unknown, but they may have a perennating function.

Peronospora sordida. [Descriptions of Fungi and Bacteria].

1991 ◽  
Author(s):  
G. Hall
Keyword(s):  
New York ◽  
North America ◽  
Northern Ireland ◽  
Downy Mildew ◽  
Geographical Distribution ◽  
Plant Pathogen ◽  
Disease Transmission ◽  
Channel Islands ◽  
Rain Splash

Abstract A description is provided for Peronospora sordida. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Scrophularia altaica, S. aquatica, S. auriculata, S. bosniaca, S. californica, S. heterophylla, S. lanceolata, S. marylandica, S. nodosa, S. scopolii, S. umbrosa (=S. alata), Verbascum banaticum, V. blattaria, V. densiflorum (=V. thapsiforme), V. glabratum subsp. glabratum, V. lychnitis, V. nigrum, V. phlomoides, V. phoenicum, V. speciosum, V. thapsus, V. thapsus subsp. crassifolium (=V. montanum), V. virgatum. DISEASE: Downy mildew of Scrophularia and Verbascum, some species of which may be cultivated commercially for their medicinal or ornamental value; an obligately necrotrophic plant pathogen. GEOGRAPHICAL DISTRIBUTION: Asia; USSR (Kirghizia, Turkmenia, Uzbekistan). Europe; Austria, Belgium, France, Czechoslovakia, Denmark, Eire, Finland, Germany, Hungary, Italy, Netherlands, Norway, Poland, Rumania, USSR (Byelorussia, Estonia, Latvia, Lithuania, RSFSR, Ukraine), Sweden, Switzerland, UK (England, Channel Islands, Northern Ireland, Scotland, Wales), Yugoslavia. North America; USA (California, Illinois, Indiana, Iowa, Kansas, Kentucky, Missouri, Nebraska, New York, Ohio, Wisconsin, Virginia). TRANSMISSION: By spores ('conidia') dispersed by wind or rain-splash. The role of oospores (if they are usually formed) in disease transmission is unknown.

Phyllactinia mali. [Descriptions of Fungi and Bacteria].

1998 ◽  
Author(s):  
V. P. Heluta
Keyword(s):  
Geographical Distribution ◽  
Disease Transmission ◽  
Western Siberia ◽  
Prunus Avium ◽  
Cydonia Oblonga ◽  
Rosa Canina ◽  
Initial Stage ◽  
Cultivated Species ◽  
Padus Avium

Abstract A description is provided for Phyllactinia mali. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Powdery mildew of different arboreal Rosaceae, including important cultivated species. Mycelium, conidiophores, conidia and ascomata develop on lower part of leaves without any visible damage. This disease is dangerous for pear seedlings in nurseries only. HOSTS: Amelanchier canadensis, A. ovalis (A. vulgaris), Cotoneaster bacillaris (?), Crataegus brevispina, C. curvisepala (C. kyrtostyla, C. oxycantha), C. douglasii, C. laevigata, C. lindmanii (C. calycina), C. meyeri, C. monogyna, C. nigra, C. orientalis (C. laciniata), C. pallasii, C. parviflora, C. pentagyna, C. sanguinea, C. scabrifolius, C. taurica, Cydonia oblonga, Malus domestica, M. pumila, M. sylvestris, Mespilus germanica, Prunus avium (Cerasus avium[Prunus avium]) (?), P. cerasus (Cerasus vulgaris[Prunus cerasus]) (?), P. padus (Padus avium[Prunus padus]) (?), P. spinosa (?), Pyrus caucasica, P. communis, P. cordata, P. elaeagnifolia, P. lindleyi, P. pashia, P. pyraster, P. pyrifolia, ('P. sativa Fakirova'), P. zangezura, Rosa canina (?), Sorbus aucuparia (?), S. torminalis (?). [Type host -Malus sp.] GEOGRAPHICAL DISTRIBUTION: Africa: Algeria, Morocco. Asia (temperate areas only): Armenia, Azerbaijan, China, Cyprus, Republic of Georgia, India, Iran, Israel, Japan, Korea, Lebanon, Nepal, Pakistan, Russia (western Siberia), Taiwan, Turkey, Turkmenistan. Europe: Austria, Belgium, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Great Britain, Greece, Hungary, Ireland, Italy, Netherlands, Norway, Poland, Portugal, Rumania, Slovakia, Spain, Sweden, Switzerland, Turkey (European part), Ukraine, former Yugoslavia. North America: Canada, USA. TRANSMISSION: By wind-dispersed conidia. The rôle of ascospores in disease transmission is unknown, although it has been supposed that they can cause the initial stage of the disease.

Peronospora euphorbiae. [Descriptions of Fungi and Bacteria].

1994 ◽  
Author(s):  
G. Hall
Keyword(s):  
South Africa ◽  
North America ◽  
South Dakota ◽  
Downy Mildew ◽  
Geographical Distribution ◽  
Disease Transmission ◽  
Rain Splash

Abstract A description is provided for Peronospora euphorbiae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Euphorbia dulcis, E. paralias, E. peploides, E. peplus, E. platyphylla, E. prostrata, E. serpens, E. serpyllifolia, E. serratula (= E. stricta). DISEASE: Downy mildew of Euphorbia species. Leaf lesions are hypophyllous, but superficial in E. paralias, as it has stomata on the upper surface of its leaves, which curl upwards. GEOGRAPHICAL DISTRIBUTION: Africa: South Africa. Asia-Temperate: Japan. Europe: France, Italy, Majorca, Poland, Romania, Spain, Switzerland, UK (England). North America: USA (South Dakota, Texas). TRANSMISSION: By conidia which are dispersed by wind or rain-splash. The role of oospores in disease transmission is unknown, but they may serve as perennating structures.

Peronospora potentillae. [Descriptions of Fungi and Bacteria].

1991 ◽  
Author(s):  
G. Hall
Keyword(s):  
British Columbia ◽  
North America ◽  
Downy Mildew ◽  
Geographical Distribution ◽  
Plant Pathogen ◽  
Disease Transmission ◽  
Washington State ◽  
Fragaria Vesca ◽  
Rain Splash

Abstract A description is provided for Peronospora potentillae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Potentilla argentea, P. aurea subsp. aurea, P. aurea subsp. chrysocraspeda (=P. ternata), P. crantzii, P. pabelliformis, P. gracilis subsp. nuttallii (=P. nuttallii), P. grandiflora, P. nepalensis, P. norvegica, P. norvegica var. hirsuta, P. pulcherrima, P. sterilis. Possibly Fragaria vesca and F. moschata, but see below. DISEASE: Downy mildew of Potentilla species; an obligately necrotrophic plant pathogen. GEOGRAPHICAL DISTRIBUTION: Asia; India, USSR (Uzbekistan). Europe; Czechoslovakia, Denmark, Eire, Finland, France, Germany, Italy, Norway, Poland, Rumania, Sweden, Switzerland, UK (England, Wales, Scotland), USSR (Latvia; RSFSR). North America; USA (Arkansas, Colorado, Idaho, Indiana, Iowa, Kansas, Michigan, New Jersey, Oregon, Texas, Washington State, Wisconsin, Wyoming), Canada (British Columbia, Saskatchewan) TRANSMISSION: By spores ('conidia') dispersed by wind or rain-splash. The role of oospores (if they are usually formed) in disease transmission is unknown.

Peronospora chlorae. [Descriptions of Fungi and Bacteria].

1994 ◽  
Author(s):  
G. Hall
Keyword(s):  
The Netherlands ◽  
Downy Mildew ◽  
Geographical Distribution ◽  
Disease Transmission ◽  
Republic Of Georgia ◽  
Rain Splash

Abstract A description is provided for Peronospora chlorae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Blackstonia (=Chlora) imperfoliata, B. perfoliata, B. serotina, Centaurium pulchellum, Erythraea centaureum, E. roxburghii, Eustoma russelianum (=Lisianthus russelianus). DISEASE: Downy mildew of Blackstonia and Eustoma. GEOGRAPHICAL DISTRIBUTION: Asia-Temperate: Abkhasiya, Azerbaijan, Republic of Georgia. Asia-Tropical: India. Europe: Denmark, France, Hungary, Italy, The Netherlands, Portugal, Spain, Switzerland, Ukraine, UK (England, Guernsey, Jersey), Yugoslavia. TRANSMISSION: By conidia dispersed by wind or rain-splash. The role of oospores in disease transmission is unknown, but they may act as perennating structures.

Arthrocladiella mougeotii. [Descriptions of Fungi and Bacteria].

1998 ◽  
Author(s):  
V. P. Heluta
Keyword(s):  
Czech Republic ◽  
Geographical Distribution ◽  
Disease Transmission ◽  
Russian Far East ◽  
Far East ◽  
Republic Of Georgia ◽  
Lycium Barbarum ◽  
Initial Stage ◽  
High Infection

Abstract A description is provided for Arthrocladiella mougeotii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Powdery mildew of Lycium species only. The mycelium, conidiophores, conidia and ascomata form first white, then dirty-grey patches on damaged green parts of the host. Infected parts are deformed slightly and, in cases of high infection, plants can lose their ornamental qualities. Damaged leaves can fall prematurely. HOSTS: Lycium barbarum (= L. europaeum), L. chinense, L. dasystemum, L. halimifolium, L. ovatum, L. potaninii, L. rhombifolium, L. ruthenicum. [Type host - Lycium barbarum] GEOGRAPHICAL DISTRIBUTION: Africa: Canary Islands. Asia (temperate areas only): Armenia, Azerbaijan, China, Republic of Georgia, Israel, Japan, Kazakhstan, Kirghizistan, Korea, Russia (Russian far east), Tadzhikistan, Taiwan, Turkey, Turkmenistan, Uzbekistan. Australasia: New Zealand (introduced). Europe: Austria, Belgium, Bulgaria, Czech Republic, Estonia, France, Germany, Hungary, Italy, Netherlands, Norway, Poland, Rumania, Slovakia, Sweden, Switzerland, UK, Ukraine (southern), former Yugoslavia. North America: USA (introduced). TRANSMISSION: By wind-dispersed conidia. The rôle of ascospores in disease transmission is unknown, although it has been supposed that they can cause the initial stage of the disease.

Podosphaera myrtillina. [Descriptions of Fungi and Bacteria].

1998 ◽  
Author(s):  
V. P. Heluta
Keyword(s):  
Geographical Distribution ◽  
Disease Transmission ◽  
Russian Far East ◽  
Far East ◽  
Moscow Oblast ◽  
East Siberia ◽  
Initial Stage ◽  
Oxycoccus Palustris ◽  
Host Development

Abstract A description is provided for Podosphaera myrtillina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Powdery mildew of plants belonging to the Vacciniaceae only. Infected plants usualy change colour, Ascomata form a brown layer on damaged green parts of host. Development of the disease can by epiphytotic, in which case the crop of berries can be significantly reduced. HOSTS: Arctostaphylos alpina (?), Ledum groenlandicum (?), Vaccinium angustifolium (V. pennsylvanicum), V. × intermedium (V. myrtillus × vitis-idaea), V. membranaceum, V. myrtillus, V. oxycoccos (Oxycoccus palustris, O. quadripetalus), V. uliginosum, V. vitis-idaea. [Type species - Vaccinium myrtillus] GEOGRAPHICAL DISTRIBUTION: Asia (temperate areas only): Republic of Georgia, Russia (all Russian far east including Kamchatka; west, south and east Siberia including Yakutia). Europe: Austria, Belgium, Bulgaria, Czech Republic, Denmark, Estonia, Finland, France, Germany, Great Britain, Greenland, Hungary, Iceland, Italy, Latvia, Lithuania, Netherlands, Norway, Poland, Rumania, Russia (western and northwestern areas of European part, Moscow oblast'), Slovakia, Sweden, Switzerland, Ukraine, former Yugoslavia. North America: Canada, USA (including Alaska). TRANSMISSION: Probably by wind-dispersed conidia. The rôle of ascospores in disease transmission is unknown, although it has been supposed that they can cause the initial stage of the disease. Infection can also, however, occur from colonies surviving in host buds. In addition, ascomata of Podosphaera myrtillina, especially of var. major, intertwine their appendages to form clusters which are dispersed by rain or wind.

Peronospora dianthicola. [Descriptions of Fungi and Bacteria].

1983 ◽  
Author(s):  
S. M. Francis
Keyword(s):  
Downy Mildew ◽  
Geographical Distribution ◽  
Disease Transmission ◽  
Dianthus Caryophyllus ◽  
Weather Conditions ◽  
Axillary Buds ◽  
Pseudoperonospora Humuli ◽  
Resistant Varieties ◽  
Weed Hosts ◽  
Pale Green

Abstract A description is provided for Peronospora dianthicola. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Dianthus caryophyllus. DISEASE: Downy mildew of carnation. Early symptoms are seen on the leaves which have pale green to yellowish transverse bands and may bend at these lesions. Infected plants are stunted and become withered. Infection of the growing point may result in the development of axillary buds giving the plants a bushy appearance. Barthelet describes the shoots which can develop in some resistant varieties as resembling the basal spikes of Pseudoperonospora humuli on hops, i.e., shoots with smaller leaves, thickened stem and shortened internodes. GEOGRAPHICAL DISTRIBUTION: Europe (Britain*, Denmark, France, Greece, Turkey); N. America (California, USA); S. America (Colombia). *no herbarium material, but recorded by F.A. Mason, The Naturalist no. 848: 270, 1927; on leaves of carnation under glass, Duncombe Park, Helmsley, Yorks. (Sept. 1920). TRANSMISSION: Oospores, which are formed abundantly in the tissues of diseased plants, are thought to be important in disease transmission. A small amount of infection is often seen on the plants in the autumn and these foci can allow the pathogen to overwinter until more favourable weather conditions permit the spread of the disease the following spring. Possible weed hosts for the pathogen such as Cerastium and Stellaria, growing in the vicinity, were examined and found to be infected with a different species of Peronospora belonging to the P. alsinearum group (33, 230).

Microsphaera palczewskii. [Descriptions of Fungi and Bacteria].

1998 ◽  
Author(s):  
V. P. Heluta
Keyword(s):  
Geographical Distribution ◽  
Disease Transmission ◽  
Russian Far East ◽  
Ornamental Plants ◽  
Far East ◽  
European Part ◽  
Southern Siberia ◽  
Initial Stage ◽  
Caragana Arborescens

Abstract A description is provided for Microsphaera palczewskii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Powdery mildew of ornamental plants. Mycelium, conidiophores, conidia and ascomata form a covering of damaged green parts of the host which is first white, then dirty-grey. Infected part lose their shape. If infection levels are high, the plants may lose their ornamental qualities. HOSTS: Caragana arborescens, C. boisii, C. brevispina, C. decorticans, C. fruticosa, C. manchurica, C. microphylla, C. mollis, C. spinosa, C. ussuriensis, Robinia pseudacacia. [Type species - Caragana arborescens] GEOGRAPHICAL DISTRIBUTION: Asia (temperate areas only): China, Kazakhstan, Russia (Altai, Russian far east, southern Siberia), Turkmenistan. Europe (introduced): Belarus, Germany, Latvia, Lithuania, Poland, Rumania, Russia (European part), Slovakia, Spain, Sweden, Ukraine. TRANSMISSION: By wind-dispersed conidia. The rôle of ascospores in disease transmission is unknown, although it has been supposed that they can cause the initial stage of the disease. Infection can however also be through colonies surviving in host buds.

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