Drechslera stenospila. [Descriptions of Fungi and Bacteria].

Author(s):  
M. B. Ellis

Abstract A description is provided for Drechslera stenospila. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Saccharum officinarum. DISEASE: Brown stripe of sugarcane. The linear spots turn reddish and elongate parallel to the long axis of the leaf; usually 2-10 mm long, often reach 25 mm and may be up to 75 mm but the streaks and runners characteristic of eye spot of sugarcane (D. sacchari, CMI Descript. 305) are absent. The spots may coalesce producing large necrotic areas. Comparisons between these 2 pathogens have been made (7: 401; 8: 134; 29: 477). GEOGRAPHICAL DISTRIBUTION: Has been reported from many sugarcane growing areas (CMI Map 483, ed. 1, 1971). TRANSMISSION: Presumably by air-dispersed conidia although no studies have been reported. No natural infection on other hosts occurs.

Author(s):  
J. F. Bradbury

Abstract A description is provided for Pseudomonas alboprecipitans. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Setaria lutescens, S. italica and Zea mays. Goto & Starr (1971) and Tominaga (1971) report natural infection of Euchlaena mexicana in Japan, while the latter author also reports natural infection of Agropyron pubescens, Bromus catharticus, B. inermis and B. marginatus in Japan, and Hordeum vulgare and Oryza sativa in the Philippines. The following are recorded as susceptible to spray inoculation: Agropyron intermedian ?, Alopecurus pratensis, Arrhenatherum elatius, Avena sativa, Echinochloa frumentacea, Festuca elatior, Holcus lanatus, Lolium multiflorum, Poa pratensis, Phalaris arundinacea, Secale cereale, Setaria geniculata, Sorghum vulgare, S. vulgare var. sudanense, Triticum aestivum. Goto & Starr (1971) also report slight infection of Phaseolus vulgaris with wounding. DISEASE: Bacterial leaf blight and stalk rot of maize and teosinte; bacterial brown stripe of foxtail and various other grasses. On leaves and sheaths spots and streaks are produced. They vary in size and in colour from yellowish or pale brown to dark brown, depending on the host and conditions. On maize, if the stalk rot occurs it is on the upper part of the stem, often at the level where the ears are produced. The top of the plant dies and bleaches. The ears are usually sterile and sometimes become rotted. GEOGRAPHICAL DISTRIBUTION: USA (Alabama, Arkansas, Florida, Georgia, Kansas, Montana, Nebraska, Texas, Virginia), Brazil, Japan, Philippines. TRANSMISSION: Presumably transmitted mainly by wind and rain. Entry into the plant is through stomata and hydathodes and, although bacterial exudate is not seen, large numbers of bacteria can emerge on to wet leaf surfaces, especially on damaged leaves.


Author(s):  
G. S. Saddler

Abstract A description is provided for Acidovorax avenae subsp. avenae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Agropyron intermedium, A. trichophorum, Avena sativa, Bromus catharticus, B. marginatus, Camellia sinensis (may form a complex with Pseudomonas syringae pv. theae: 68, 955), Caryota mitis, Digitaria sanguinalis, Echinochloa crusgalli, Eleusine coracana, Euchlaena mexicana, Oryza sativa, Panicum hirsutum, P. miliaceum, Paspalum nutans, P. paniculatum, P. urvillei, Pennisetum americanum, Saccharum officinarum, Setaria italica, S. lutescens, S. viridis, Sorghum bicolor and Zea mays. DISEASE: Bacterial leaf blight of maize and sorghum, brown stripe of rice and red stripe of sugarcane. Symptoms in general consist of leaf streaks and stripes, which may extend into the sheaths. Occasionally a stalk rot develops. Symptoms are more severe on seedlings and immature plants. Discolouration of seeds can occur on rice. In fishtail palm (Caryota mitis), lesions are mainly at the leaf margin and brown/black with a chlorotic halo (Miller, 1992). In most cases conditions of high temperature and high relative humidity favour symptom development. GEOGRAPHICAL DISTRIBUTION: Comoro Is., Egypt, Ethiopia, Ivory Coast, Kenya, Madagascar, Mauritius, Malawi, Mozambique, Niger, Nigeria, Reunion, Sierra Leone, South Africa, Sudan, Tanzania, Uganda, Zaire, Zimbabwe, Bangladesh, Burma, Bhutan, Cambodia, China, India, Indonesia, Iran, Iraq, Japan, Korea, Malaysia, Nepal, Okinawa, Pakistan, Philippines, Sri Lanka, Taiwan, Thailand, Vietnam, Australia, Fiji, Guam, Papua New Guinea, Tahiti, Italy, Portugal, Turkey, Mexico, USA (Alabama, Arkansas, Florida, Georgia, Illinois, Hawaii, Kansas, Louisiana, MT, Nebraska, New York, Pennsylvania, Texas & Virginia), Barbados, Costa Rica, Cuba, Dominican Republic, El Salvador, Guadeloupe, Guatemala, Honduras, Jamaica, Martinique, Nicaragua, Panama, Puerto Rico, St. Kitts, Trinidad, Argentina, Brazil (Sao Paulo), Colombia, Guyana, Paraguay, Peru, Surinam, Uruguay, Venezuela (CMI Map 511 ed. 1, 1976 & CMI Map 39 ed. 5, 1987). TRANSMISSION: The disease is largely thought to be seed borne. In rice, the bacterium is located between the glumes and the pericarp, or deeper in the seed (Shakya et al., 1986). There is evidence to suggest that mature plants which survive infection in the seedling stage harbour latent infections. The bacterium can be found in 8-yr old rice seed samples stored at 5°C (Shakya et al., 1985). The bacterium is not thought to survive well in soil or in plant debris. Alternative hosts such as Paspalum urvillei (Vasey grass) in Florida, USA have been noted as an inoculum reservoir in bacterial leaf blight of maize outbreaks (Shurtleff, 1973; 57, 4929).


Author(s):  
K. E. Reay

Abstract A description is provided for Xanthomonas campestris pv. graminis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Lolium italicum, L. multiflorum, L. perenne, Dactylis glomerata, Festuca pratensis, and Trisetum flavescens. Single cases of natural infection of Agropyron repens, Phalaris arundinacea and Phleum pratense are also recorded (62, 241), but their status in the natural host range is unknown. In inoculation tests (Egli et al., 1975; Egli & Schmidt, 1982) the following were highly susceptible: Alopecurus pratensis, Dactylis glomerata, Festuca arundinacea, F. pratensis, F. rubra, Lolium loliaceum, L. multiforum, L. parabolicae, L. perenne, L. remotum, L. temulentum, Phleum arenarium and P. bertolonii. Showing much less susceptibility were Agrostis alba, Arrhenatherum elatius, Phleum alpinum, P. phleoides, P. pratense, Poa annua, P. compressa, P. fertilis, P. memoralis, P. pratensis and P. trivialis. Leyns et al. (61, 6162) found that Agrosas tenuis and Festuca ovina were moderately susceptible when inoculated. Egli et al. (1975) recorded doubtful symptoms on Hordeum vulgare and Triacum aestivam on inoculation, but consider that they are unlikely to be naturally infected. DISEASE: Bacterial wilt of forage grasses. Symptoms usually first noticed at the heading stage, when young leaves curl and wither, and shoots remain stunted or may die. Other plants will continue to make poor growth and produce small, distorted inflorescences. Chlorotic and necrotic zones form on the older leaves along long stretches of vascular bundles, often extending into the sheaths. Bacterial streaming may be seen under the microscope from the cut ends of vascular bundles of infected tissue mounted in water. GEOGRAPHICAL DISTRIBUTION: CMI Map 533, ed. 1, 1979 lists France, Germany, Switzerland and Wales, to which must be added Scotland (63, 2925), Belgium (61, 4199), Netherlands, Norway (62, 241), and New Zealand (62, 241). Possibly in USA (IL; 61, 5045) though this disease is currently attributed to a Rickettsia- like organism. TRANSMISSION: Within the crop transmission is presumed to be by the blades of mowing machines.


Author(s):  
J. F. Bradbury

Abstract A description is provided for Xanthomonas oryzae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Oryza sativa. Natural infection of Leersia oryzaides, Leersia oryzaides var. japonica and Zizania latifolia[Zizania aquatica] is known (Mizukami & Wakimoto, 1959). Natural infection of Cyperus rotundus and C. difformis was reported in India (48, 460), but inoculation of these hosts in the Philippines failed (48, 1689). By inoculation many wild species of Oryza (45, 1789), Leptochloa filiformis (48, 1689), L. chinensis, L. panacea and Zizania aquatica (48, 1683) have all been found susceptible. DISEASE: Bacterial blight of rice and kresek disease of rice. Blight most commonly appears on leaves of young plants, after planting out, as water-soaked stripes at the margins. These enlarge and coalesce to give the characteristic yellowish lesions with wavy edges that occur mainly along the margins of the upper parts of the leaves. These lesions may later expand to cover much of the leaf, which turns whitish or greyish and dies. Leaf sheaths of the more susceptible varieties may be affected. Kresek, which occurs in tropical regions, is a strong systemic infection in which leaves or whole young plants wither and die. In older plants the leaves become pale yellow. GEOGRAPHICAL DISTRIBUTION: Limited to Asia (CMI Map 304, ed. 2, 1964). Occurrences not shown on this map include Korea, Taiwan and Indonesia (Mizukami & Wakimoto, 1969). TRANSMISSION: Spread locally by wind and rain and also by flood and irrigation waters; gains entry to the field in infected planting material, to the nursery in seed, and to both nursery and field from volunteer rice plants and weed hosts usually via the irrigation water. Overwintering may occur on volunteers, on or in the rhizospheres of weed hosts, in stored infected straw and in seed, but it is unlikely in soil and plant debris exposed to the weather, at least under Japanese conditions (Mizukami & Wakimoto, 1969). Infection is through hydathodes and wounds. Penetration through stomata results in a build-up of bacteria in the intercellular spaces, but it is not until they have been exuded on to the leaf surface and re-admitted through the hydathodes and thence into the vascular system, that symptoms of the disease appear (46, 2720).


2012 ◽  
Vol 45 (1) ◽  
pp. 60-65 ◽  
Author(s):  
Maria Beatriz Araújo Silva ◽  
Ana Virgínia Matos Sá Barreto ◽  
Helker Albuquerque da Silva ◽  
Cleber Galvão ◽  
Dayse Rocha ◽  
...  

INTRODUCTION: The present study shows a descriptive analysis of triatomine occurrence and its natural Trypanosoma infection rates in the state of Pernambuco, Brazil, between 2006 and 2007. METHODS: Entomological data for the species, such as specimens captured in both intra and peridomiciles and natural infection index, were obtained via domiciliary capture in 147 municipalities from 11 Regional Managements of Health. The database was obtained from a sample of insects (100% infected and 20% non-infected) sent to the Central Laboratory of Pernambuco. RESULTS: A total of 18,029 triatomines were analyzed from 138 municipalities of the state. Triatoma pseudomaculata (35%), Triatoma brasiliensis (34%), and Panstrongylus lutzi (25%) were the most captured species. These species also showed a widespread geographical distribution in the state. Panstrongylus megistus, Triatoma petrocchiae, Triatoma melanocephala, Triatoma sordida, Rhodnius nasutus, Rhodnius neglectus, and Triatoma infestans showed more limited geographical distribution and lower relative abundance. The parasitological research showed that 8.8% of the triatomines were naturally infected with flagellates morphologically similar to Trypanosoma cruzi and 91.3% of them were captured inside houses in 113 municipalities. P. lutzi showed the highest rates of natural infection. CONCLUSIONS: After the control of T. infestans, synanthropic species, such as T. brasiliensis, T. pseudomaculata, and P. lutzi, maintain the risk of T. cruzi transmission to humans in the state of Pernambuco. These species are widely distributed, and infected specimens have been found inside houses. Thus, an enhanced surveillance and vector control of Chagas disease is recommended in Pernambuco.


Author(s):  

Abstract A new distribution map is provided for Heterodera sacchari Luc & Merny Nematoda: Tylenchida: Heteroderidae Hosts: Sugarcane (Saccharum officinarum) and rice (Oryza sativa). Information is given on the geographical distribution in ASIA, India, Delhi, Pakistan, Thailand, AFRICA, Benin, Burkina Faso, Chad, Congo, Cote d'Ivoire, Gambia, Ghana, Liberia, Nigeria, Senegal.


Author(s):  
J. C. David

Abstract A description is provided for Alternaria longissima. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On pollen grains, husks and grains of numerous members of the Poaceae, such as Zea mays, Pennisetum typhoides, Saccharum officinarum and Oryza sativa; on seeds of Sesamum and Capsicum, and on diverse plant debris. DISEASE: None is normally caused in the natural environment, however it is reported as causing stem and leaf blight of sunflowers in Thailand (71, 5765), as well as a zonate leaf spot and stem necrosis of Sesamum (61, 5893). GEOGRAPHICAL DISTRIBUTION: Africa: Egypt, Malawi, Nigeria, Sierra Leone, Sudan, Tanzania, Zambia. C. & S. America: Cuba, Venezuela. N. America: Bermuda, USA (GA, NC). Asia: Bhutan, Brunei, India, Laos, Malaysia, Nepal, South Korea, Taiwan, Thailand. Europe: Ukraine. Australasia & Oceania: Australia (QLD, VIC), New Zealand, Solomon Islands (Guadalcanal, New Georgia). TRANSMISSION: By wind dispersal of airborne conidia as well as on seeds.


Author(s):  
J. F. Bradbury

Abstract A description is provided for Erwinia chrysanthemi. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a number of widely different plants, including Aechmea fasciata, Aglaonema pictum, Ananas comosus, Begonia bertini, Chrysanthemum spp., Colocasia esculenta, Dahlia spp., Dianthus caryophyllus, Dieffenbachia spp., Euphorbia pulcherrima, Musa sp., Parthenium argentatum, Philodendron spp., Saccharum officinarum, Saintpaulia ionantha, Syngonium podophyllum and Zea mays. DISEASE: Symptoms are stunting, yellowing, wilting, necrosis of parenchyma or soft rotting according to host plant, pathotype and environmental conditions. Stunting and wilting usually appear on Begonia, Chrysanthemum, carnation, Dahlia and poinsettia. Rots appear on leaves of Aechmea, Philodendron and Saintpaulia, while various other parts show rotting with other hosts. On sugarcane a leaf mottle is produced. GEOGRAPHICAL DISTRIBUTION: The species is probably world wide, but the different distributions of the strains or pathotypes (see below) must be distinguished as follows: Dianthus: Europe (CMI Map 425, ed. 1, 1967) to which should be added Italy (46, 3461), USA (47, 2498) and New Zealand (52, 3341); Zea: Egypt, Sudan, Rhodesia, S. Africa, India, USA, France, Italy, possibly Greece; Chrysanthemum: UK, Germany, Italy, Canada, USA, Japan; Dahlia: Netherlands, Romania; Dieffenbachia: Germany, Italy, USA; Saintpaulia: France, Germany, USA; Begonia: Netherlands; Aechmea: Italy; Ananas: Malaysia; Colocasia: Solomon Islands; Musa: Central America and probably most other banana-growing areas; Philodendron, Parthenium, Euphorbia and Aglaonema: all confined to USA; Saccharum: Australia (Qd., NSW). TRANSMISSION: Usually in or on vegetative propagating material. Cuttings and setts from infected plants are frequently infected. Cutting knives may carry inoculum to healthy material. Transmission in soil and planting medium is also possible. Serious outbreaks have occurred after holding a large number of cuttings together in water prior to planting. The sugarcane pathogen is rapidly spread by flood water (48, 2533). Maize stalk rot is carried by water splash. It is often associated with overhead irrigation (48, 1675; 55, 204).


Author(s):  

Abstract A new distribution map is provided for Melanotus communis Gyllenhal. Coleoptera: Elateridae. Main hosts: sugarcane (Saccharum officinarum), potato (Solanum tuberosum), many grasses, and some vegetables and cereals. Information is given on the geographical distribution in North America (Ontario and Quebec, Canada, and Alabama, Arizona, Arkansas, Colorado, Florida, Georgia, Illinois, Indiana, Iowa, Louisiana, Maryland, Massachusetts, Minnesota, Missouri, Nebraska, New Jersey, New York, North Carolina, North Dakota, Ohio, Pennsylvania, South Carolina, South Dakota, Texas, Virginia and Wisconsin, USA).


Author(s):  
A. Sivanesan

Abstract A description is provided for Khuskia oryzae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Plurivorous, especially on monocotyledons and particularly on Oryza sativa, Saccharum officinarum, Zea mays and Musa spp. DISEASE: Causes cob and stalk rot of maize (11: 711; 12: 20; 13: 299, 571; 43, 3205; 44, 2123) and on sorghum as stem and grain infection (43, 727); it is common on banana debris in the western hemisphere and can cause discolouration in rice irain. On maize, symptoms develop towards maturity mostly on the shanks, husks and ears but also on the stems and stalks, where blackish, shallow lesions can occur. Ears may snap off at harvest; the cob becomes shredded and rotten through disintegration of the parenchyma, sparse mycelium and sporulation develop in the furrows between kernels and on the seed itself. GEOGRAPHICAL DISTRIBUTION: Widespread, principally as a member of the saprophytic flora on plant debris in warmer areas. TRANSMISSION: Infection of seed reduces its quality rather than causing the fungus to be really seed-borne. A diurnal periodicity has been reported for Nigrospora sphaerica and K. oryzae, with a peak at 0800-1000 hr, in the tropics (35: 383; 41: 242). Violent spore discharge, a rare phenomenon in the hyphomycetes, has been described for N. sphaerica (31: 56).


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