Pseudomonas mors-prunorum. [Descriptions of Fungi and Bacteria].

Author(s):  
J. F. Bradbury

Abstract A description is provided for Pseudomonas mors-prunorum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Prunus spp. especially plum and cherry. DISEASE: Bacterial canker, leaf spot and shoot wilt of stone wits. A definite seasonal cycle occurs in which a winter canker alternates with a summer leaf spot (Crosse, 1954). The symptoms are indistinguishable from those caused by P. syringae on stone fruits. GEOGRAPHICAL DISTRIBUTION: Mainly in Europe, where it has been reported from Denmark, Finland, France, Germany, Great Britain, Greece, Ireland, Netherlands, Switzerland, Rumania, U.S.S.R. (Ukraine), Yugoslavia and, recently, (46, 381) from Italy. Also in Australia (N.S.W.) and Canada (N.S.). (CMI Map 132, Ed. 2, 1966). TRANSMISSION: The pathogen is probably introduced into new orchards most frequently on plant material, where infected spurs may show such slight symptoms as to pass unnoticed (Crosse, 1954). The pathogen is spread locally by wind and rain. In early summer young leaves can be invaded but stems become difficult or impossible to infect at this time. As the leaves mature they lose their susceptibility and large numbers of bacteria are found on their surfaces. These bacteria are carried by rain to infect the branches, which are again susceptible in the autumn, through wounds and incompletely healed leaf scars. This autumn infection leads to the canker phase that develops slowly through the winter and in the spring causes infection of the new leaves as they expand. In summer the bacteria in the cankers die out. The cankers are not, therefore, perennial, but are readily reinfected in the autumn.

Author(s):  
S. Wilson

Abstract A description is provided for Ramularia pratensis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Rumex acetosa, R. aquaticus, R. acetosella, R. hydrolapathum, R. longifolius, R. obtusifolius, R. thyrsiflorus. DISEASE: Leaf spot of Rumex spp. Round or oval lesions, from (1-) 2 (-3) mm diam., with a distinct purple-brown border and buff centre. GEOGRAPHICAL DISTRIBUTION: Europe: Channel Islands, Eire, Great Britain, Germany, Hungary, Italy, Sweden. TRANSMISSION: Probably wind-dispersal by air-borne spores.


Author(s):  
E. Punithalingam

Abstract A description is provided for Diaporthe manihotis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Manihot esculenta. DISEASE: Leaf spot of cassava (46, 64) or sometimes referred to as Phomopsis blight of tapioca (54, 2588). In the early stages of infection the visible symptoms are pale green, watersoaked, small round spots on young leaves and petioles which rapidly enlarge and turn brown. Severe attack leads to defoliation and infection spreading to the stem. Affected areas become shrivelled with numerous pycnidia embedded in the tissue. On severely infected stems the bark starts to peel off gradually leading to partial or total girdling. GEOGRAPHICAL DISTRIBUTION: Africa (Ethiopia, Nigeria); Asia (India); Central America and West Indies (S.E. Dominica); South America (Colombia). TRANSMISSION: Probably by watersplash-dispersed conidia.


Author(s):  
P. Holliday

Abstract A description is provided for Septoria helianthi. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Helianthus annuus, Helianthus grosseserratus and Helianthus rigidus. DISEASE: Leaf spot of sunflower. Yellowish spots up to 1.5 cm develop over the whole lamina, gradually turning necrotic and becoming almost black. The numerous pycnidia are mostly on the adaxial surface. The lesions have a polygonal outline, being sharply delimited by the veins. Infection may begin on the cotyledons and young leaves, spreading to later developing leaves. Severe attacks lead to defoliation and loss in yield. GEOGRAPHICAL DISTRIBUTION: Fairly widespread in E. Europe and the U.S.S.R. in Asia, China, Japan, Australia (Qd.); E. and S. Africa, N. America (CMI Map 468, ed. 1, 1970). TRANSMISSION: Overwintering occurs in host debris. Seed treatment is recommended although seed transmission does not appear to have been demonstrated. Introduction of the fungus into Hungary may have been via seed (43, 2013).


Author(s):  
G. Morgan-Jones

Abstract A description is provided for Phoma prunicola. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Malus spp., Prunus spp., and a variety of other substrates. DISEASE: Leaf spot of apple, pear and species of Prunus. Thought to be a secondary invader. Isolated from fruit rot of lemon (31: 487). GEOGRAPHICAL DISTRIBUTION: Africa (Kenya, Nigeria, Tanzania); Asia (India, Israel); Australasia (Tasmania); Europe (Bulgaria, Germany, Great Britain, Italy, Netherlands, Norway, Spain, U.S.S.R.); N. America (United States). TRANSMISSION: Probably seed and soil borne. Dissemination by rain.


Author(s):  
T. V. Andrianova

Abstract A description is provided for Septoria geranii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Leaf spot; necrotic spots, leading to leaf drying. HOSTS: Geranium carolinianum, G. collinum, G. columbinum, G. depilatum, G. dissectum, G. divaricatum, G. graveolens, G. lucidum, G. molle, G. nodosum, G. palustre, G. pratense, G. purpureum, G. pusillum, G. pyrenaicum, G. rectum, G. robertianum, G. sanguineum, G. sylvaticum, G. versicolor (Geraniaceae). GEOGRAPHICAL DISTRIBUTION: AFRICA: Canary Is, Kenya. NORTH AMERICA: USA. ASIA: Azerbaijan, Republic of Georgia [www.cybertruffle.org.uk/gruzmaps/index.htm], India, Kazakhstan, Kirgizstan, Russia, Turkmenistan, Uzbekistan. EUROPE: Belarus, Bulgaria, Estonia, France, Germany, Great Britain, Greece, Hungary, Italy, Lithuania, Norway, Poland, Portugal, Romania, Russia, Spain. TRANSMISSION: Not reported, but almost certainly by airborne or splash-dispersed conidia.


Author(s):  
D. W. Minter

Abstract A description is provided for Lophomerum ponticum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Rhododendron ponticum. DISEASE: Leaf spot of rhododendron. In general Lophomerum ponticum appears to be saprophytic. Its ascocarps are usually not produced until the leaves have senesced, become detached and fallen to the litter. Occasionally, however, ascocarps can be found on browned regions of otherwise green leaves, and it seems possible, therefore, that the species is facultatively parasitic. It is important to distinguish this species from Lophodermium vagulum (CMI Descriptions 789) which is the causal agent of a leaf spot disease of chinese rhododendrons, but which does not occur on R. ponticum. GEOGRAPHICAL DISTRIBUTION: Europe (Great Britain), probably much more widespread. TRANSMISSION: By air-borne ascospores in wet or humid weather.


Author(s):  
D. W. Minter

Abstract A description is provided for Lophodermium vagulum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Species of Rhododendron, including R. souliei × R. thomsonii, R. croceum, R. stewartianum, R. sinogrande, R. campylocarpum, R. discolor and species of the R. sanguineum series. DISEASE: Leaf spot of chinese rhododendrons. Rhododendron hybrids with R. souliei as one parent appear to be particularly susceptible: where a number of seedlings has been grown from such crosses, they do not all show equal susceptibility to the disease, suggesting that resistance to the disease is genetically controlled. In areas where the disease is present, susceptible hybrid progeny of R. soulici should not be grown. GEOGRAPHICAL DISTRIBUTION: Asia (China, India, Nepal, Upper Burma, Tibet), Europe (Great Britain). It is likely that the disease is widespread in Asia in the regions from which susceptible species of Rhododendron have been introduced to Britain. TRANSMISSION: By air-borne ascospores in wet or humid weather.


Author(s):  
J. C. David

Abstract A description is provided for Ramularia onobrychidis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Leaf spot of sainfoin. HOSTS: Arachis hypogaea, Onobrychis altissima, O. arenaria, O. hajastana, O. hohenhackeriana, O. miniata, O. oxyodonta, O. pulchella, O. sintenisii, O. transcaucasica, O. vaginalis, O. viciifolia (BRAUN, 1998) (Fabaceae). GEOGRAPHICAL DISTRIBUTION: ASIA: Armenia, Azerbaijan (EIBATOVA, 1958), Republic of Georgia, Kabardino-Balkariya, Kazakhstan, Kirgistan, Tadzhikistan (OSIPYAN, 1975), Turkmenistan, Uzbekistan. EUROPE: Austria, Belarus (OSIPYAN, 1975), Bulgaria, Denmark, Estonia, France, Germany, Great Britain, Hungary, Italy, Latvia, Lithuania, Moldova (OSIPYAN, 1975), Romania (BONTEA, 1985), Russia, Sweden, Turkey, Ukraine, Serbia. TRANSMISSION: By wind and rain-splash dispersal of conidia. HUGHES (1949) stated that sclerotia are formed in the lesions: the leaflets are readily detached and in moist conditions the sclerotia can develop after leaf fall, they can also be blown around aiding dispersal of the fungus.


Author(s):  
K. Schubert

Abstract A description is provided for Fusicladium convolvularum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Leaf spot. HOSTS: Species of Calystegia and Convolvulus (Convolvulaceae), including Calystegia sepium, C. soldanella and Convolvulus arvensis. GEOGRAPHICAL DISTRIBUTION: AUSTRALASIA: New Zealand. EUROPE: Czech Republic, Great Britain. TRANSMISSION: Presumably by airborne conidia.


Author(s):  
D. Brayford

Abstract A description is provided for Cylindrocarpon vaginae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Man. DISEASE: Human corneal infections. GEOGRAPHICAL DISTRIBUTION: Probably widespread. In CMI records there are medical reports of eye infections from Bangladesh and Great Britain. TRANSMISSION: Probably soil-borne and infection by contamination of eye with muddy water or plant material.


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