Sclerospora sacchari. [Descriptions of Fungi and Bacteria].

1975 ◽  
Author(s):  
K. G. Mukerji
Keyword(s):  
Geographical Distribution ◽  
Stem Elongation ◽  
Leaf Tissue ◽  
Systemic Infection ◽  
Seed Transmission ◽  
Saccharum Officinarum ◽  
Primary Host ◽  
Downy Mildews ◽  
Setaria Verticillata ◽  
Host Infection

Abstract A description is provided for Sclerospora sacchari[Peronosclerospora sacchari]. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Saccharum officinarum, Echinochloa colonum, Eleusine indica, Euchlaena luxurians, E. mexicana, Panicum barbinodes, Polypogon interruptus, Saccharum barberi, S. robustum, S. sinense, Setaria verticillata, Sorghum halepense, S. sudanense, S. vulgare and Zea mays (35, 125; 40, 626; 44, 648), and others cereals and grasses. DISEASE: Downy mildew of sugarcane and one of the downy mildews of maize, the others are caused by Sclerospora philippinensis[Peronosclerospora philippinensis] (CMI Descript. 454) and S. maydis (Racib.) Butler. Sclerospora sacchari has larger oogonia than S. philippinensis; these spores are unknown in S. maydis which has smaller conidia than those of S. philippinensis. The symptoms on sugarcane differ, depending on when infection occurs. When diseased setts are used the young plant may die or become generally stunted, discoloured and conspicuous. Infection at a later stage causes pale green to yellow longitudinal stripes which increase in length after each leaf unfolds. The stripes may become a chlorotic mottling, later necrotic with oospores lying interveinally. Later infections cause abnormal stem elongation (jump up canes); stems are weak, have more internodes and fewer shorter leaves which may not unfold. Shredding caused by the disintegration of leaf tissue occurs in sugarcane but not in maize. In the latter host infection at a very early growth stage causes stunting and death. Systemic infection causes chlorotic leaf streaks, small poorly filed ears (formed in abnormally large numbers), elongated ear shanks, imperfect tassels with grain and sterility (21, 347; 42, 47, 629; 48, 1166). GEOGRAPHICAL DISTRIBUTION: Australia (Qd.), Fiji, India. Japan, Philippines, Taiwan, Thailand (CMI Map 21. ed. 2. 1965). Recent records from Central America are considered doubtful (49, 3185, 3740). TRANSMISSION: In Taiwan conidial air dispersal was mostly at 0100-0300hr (50, 3701). There is evidence for seed transmission in maize (47, 2705). The role of the oospore in spread appears uncertain, most spread in sugarcane apparently occuring through the conidia, but infection of this host with the sexual spore was successful (41, 544). The fungus passes readily from one primary host to the other.

Clavibacter michiganensis subsp. nebraskensis. [Descriptions of Fungi and Bacteria].

1991 ◽  
Author(s):  
J. F. Bradbury
Keyword(s):  
Geographical Distribution ◽  
Systemic Infection ◽  
Seed Transmission ◽  
Growing Season ◽  
Saccharum Officinarum ◽  
Distribution Map ◽  
Tripsacum Dactyloides ◽  
Clavibacter Michiganensis ◽  
Clavibacter Michiganensis Subsp ◽  
Dark Green

Abstract A description is provided for Clavibacter michiganensis subsp. nebraskensis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Zea mays is the natural host. By inoculation Euchlaena mexicana, Saccharum officinarum, Sorghum bicolor, S. sudanense and Tripsacum dactyloides are infected (Schuster et al., 1973). DISEASE: Leaf freckles and wilt, or Goss's bacterial wilt and blight. The disease is characterized by the appearance of discrete, water-soaked spots, dark green to blackish at first, becoming brown and more freckle-like, then coalescing and inducing a leaf scorch. The spots may arise from direct infection or via systemic infection from roots and stems (Schuster et al., 1973). GEOGRAPHICAL DISTRIBUTION: USA (IA, IL, KS, NE). (IMI Distribution Map 549, ed. 1, 1982; 67, 4495). TRANSMISSION: The bacterium can overwinter in debris from diseased corn, particularly stubble and this is a source of primary inoculum in the new growing season. It is also present within the seed where it can remain viable for more than a year. However, experiments suggest that seed transmission is rare (Schuster et al., 1973).

Sclerospora graminicola. [Descriptions of Fungi and Bacteria].

1983 ◽  
Author(s):  
S. M. Francis
Keyword(s):  
Pearl Millet ◽  
Geographical Distribution ◽  
Pennisetum Glaucum ◽  
Systemic Disease ◽  
Leaf Tissue ◽  
Seed Transmission ◽  
Distal Portion ◽  
Sclerospora Graminicola ◽  
Complete Replacement ◽  
Pennisetum Typhoides

Abstract A description is provided for Sclerospora graminicola. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: The two hosts on which this pathogen causes diseases of major economic importance are Pennisetum typhoides[Pennisetum glaucum] (syn. P. americanum) and Setaria italica. Also recorded on Echinochloa crusgalli, E. crusgalli var. fumentacea, Eleusine indica, Panicum miliaceum, Pennisetum leonis, Saccharum of ficinarum (by inoculation only), Setaria lutescens, S. magna, S. verticillata, S. viridis and Zea mexicana. The disease is very rare on Zea mays with only two confirmed reports, Melhus & Bliss (1928) in the USA and Kenneth (1966) in Israel. DISEASE: Graminicola downy mildew; green ear of pearl millet (Pennisetum typhoides[Pennisetum glaucum]). A biotrophic plant pathogen which invades and colonizes the growing points of young graminaceous plants causing systemic disease. The first leaf to show symptoms is yellowed in the basal portion with a distinct margin between the basal colonized portion and the non colonized distal portion. Leaves formed later show increasing amounts of disease until the entire leaf shows symptoms. Under suitable conditions sporangia form in great profusion on the under surface of the diseased leaf (and, when conditions are favourable, also on the upper surface) forming a conspicuous and characteristic white 'down'. Occasionally discrete local lesions have been observed on otherwise healthy leaves in highly susceptible cultivars in W. Africa. The most distinctive appearance of the disease on pearl millet is, however, the transformation of the inflorescences to vegetative structures with various leaf-like protrusions which vary greatly in size and number from very few on an almost normal inflorescence to complete replacement of the inflorescence by small leafy shoots. As diseased organs mature they become necrotic and often contain oospores within the tissue. In pearl millet the leaves containing oospores do not shred. The areas containing oospores are a deep chocolate brown and usually appear as long stripes down the leaf. On Setaria the symptoms are similar to those observed on pearl millet except that shredding of the leaf tissue containing oospores occurs. In the phase of the disease described above the height of the infected plants differs little from that of healthy plants. Another and less frequent reaction is that the diseased plants are severely stunted, show a yellow mottle, with non-infected parts becoming a much darker green than in healthy plants; few sporangia are produced and no green ears for the plants generally do not head. This reaction is a characteristic response of certain host genotypes. GEOGRAPHICAL DISTRIBUTION: CMI Map 431, ed. 2, 1979. Note that the pearl millet pathotype has not been reported from the Americas. TRANSMISSION: Initial infection is by oospores which may remain viable for up to 10 years (Nene & Singh, 1976). Later infection comes from sporangia developing on early diseased leaves and spread by wind and rain to newly developed tillers which are produced throughout the growth of the plant (Singh & Williams, 1980). Seed transmission occurs from oospores carried with, and on, seed and there are conflicting reports of transmission from mycelium carried within seed (Williams, 1980).

Xanthomonas axonopodis. [Descriptions of Fungi and Bacteria].

1977 ◽  
Author(s):  
J. F. Bradbury
Keyword(s):  
Geographical Distribution ◽  
Seed Transmission ◽  
Saccharum Officinarum ◽  
Vascular Bundles ◽  
Xanthomonas Axonopodis ◽  
Digitaria Decumbens ◽  
Pasture Grasses ◽  
Tropical America ◽  
Rain Splash ◽  
Short Time

Abstract A description is provided for Xanthomonas axonopodis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Axonopus scoparius, A. micay, A. compressus and A. affinis. Also able to infect by inoculation Digitaria decumbens, Hypharrhenia rufa, Panicum sp. (Guinea grass) and Saccharum officinarum (54, 5464). DISEASE: Gummosis of Imperial and Micay grasses, important pasture grasses in tropical America. Diseased stems usually stand out from healthy ones in the same tuft by their elongated, partly bare appearance with a few pale, yellowish leaves at their ends, giving a characteristic flag-like appearance. Closer examination shows many diseased leaves with pale stripes running parallel to the main veins. After cutting diseased Imperial grass the new shoots are feeble and twisted, and often wither in a short time. Subsequent shoots behave in the same way. In severe attacks of whole tuft may shrivel and die. Such tufts are very easily pulled from the soil. When diseased stems are cut across, especially in the rainy season, minute droplets of yellowish bacterial ooze appear in a short time. In longitudinal cuts the vascular bundles are seen to be stained reddish or brownish, especially near the nodes. Masses of bacteria and mucilage are found in vessels when examined under the microscope. GEOGRAPHICAL DISTRIBUTION: Colombia. TRANSMISSION: Mainly by machete and other agricultural implements. Cattle can infect young shoots when grazing, evidently transmitting the bacteria in their saliva. Trampling by cattle and man and the passage of wheeled vehicles can also transmit the disease, and rain splash can carry infection from the exudate of recently cut stems. Insect transmission is not thought to be important and the bacteria do not survive free in the soil (46, 666). Seed transmission is also thought to occur (43, 2799c).

Peronospora trifoliorum. [Descriptions of Fungi and Bacteria].

1983 ◽  
Author(s):  
S. M. Francis
Keyword(s):  
Medicago Sativa ◽  
Downy Mildew ◽  
Geographical Distribution ◽  
Systemic Infection ◽  
Seed Transmission ◽  
Field Conditions ◽  
Infected Leaf ◽  
Light Green

Abstract A description is provided for Peronospora trifoliorum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Medicago sativa subsp. saliva, M. sativa subsp. falcata. DISEASE: Downy mildew of lucerne (alfalfa). Infected leaflets, which tend to be near the top of the stem, are light green or yellow. The affected areas can vary from small localized spots to larger areas of infected leaf or a systemic infection where the entire shoot may become yellow, stunted and swollen. GEOGRAPHICAL DISTRIBUTION: Worldwide, wherever lucerne is grown. CMI Map No. 343 includes records on clover and other hosts. TRANSMISSION: Mycelium is reported to overwinter in the crown bud (42, 617). Conidia are produced the following spring and in damp and humid conditions soon spread the disease. Oospores occur but reports on their frequency under field conditions are so few that it is difficult to assess their importance in overwintering the disease. Seed transmission, though suspected by Eriksson (1930) and also reported from Italy in a sample of seed from Argentina (Campbell, 1922), is thought to be unimportant (Richardson, 1979).

Pseudomonas andropogonis. [Descriptions of Fungi and Bacteria].

1973 ◽  
Author(s):  
J. F. Bradbury
Keyword(s):  
Geographical Distribution ◽  
Leaf Spot ◽  
Rapid Development ◽  
Trifolium Subterraneum ◽  
Seed Transmission ◽  
Saccharum Officinarum ◽  
Leaf Spot Disease ◽  
Wet Season ◽  
Velvet Bean ◽  
Stem Lesions

Abstract A description is provided for Pseudomonas andropogonis[Burkholderia andropogonis]. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Sorghum vulgare[Sorghum bicolor] and its vars. sudanense, technicum, saccharatum, S. halepense and unspecified grain and grass varieties of Sorghum, Zea mays, Bougainvillea sp., Mucuna deeringiana, Trifolium repens, T. pratense, Euchlaena mexicana and Vicia saliva. The following have been infected artificially: Medicago sativa, Viciafaba, Trifolium subterraneum by spray inoculation, and Dolichos lablab, Lespedeza sp., Phaseolus vulgaris (Allen et al. ; 36, 408) and Saccharum officinarum (Elliott & Smith, 1929) after injury. DISEASE: Bacterial stripe of sorghum, bacterial leaf spot or blight of velvet bean, vetch and other legumes. usually a leaf spot disease. On species of Sorghum spots and stripes on leaves and sheaths vary in colour from reddish or purplish-brown to tan or brick red, depending on host reaction. On legumes the spots are usually small, angular, dark brown to dark reddish-brown or nearly black. Stem lesions are extensive in vetch, where they can result in death progressively from the base. GEOGRAPHICAL DISTRIBUTION: Argentina, Brazil, USA, Rhodesia, Uganda, Zambia, South Africa, Nigeria, Hungary, USSR, China, Australia (NSW), Japan, Taiwan (CMI Map 495, ed. 1, 1973). TRANSMISSION: In the field transmission is by wind and rain and can lead to very rapid development of the disease if conditions remain humid. Overwintering is thought to take place in plant debris, in soil and possibly in weed hosts (42, 194). There is some observational evidence for seed transmission in Sorghum (Elliott & Smith, 1929) and in Mucuna (Allen et al, 1970). This would explain the very scattered distribution. With Bougainvillea, when the new wet season starts, the young growth is infected by rain splash from old infected leaves that have lasted over from the previous wet season, either attached or on the ground.

Phoma insidiosa. [Descriptions of Fungi and Bacteria].

1972 ◽  
Author(s):  
E. Punithalingam
Keyword(s):  
South Africa ◽  
Triticum Aestivum ◽  
Puerto Rico ◽  
Sierra Leone ◽  
Geographical Distribution ◽  
Seed Transmission ◽  
Saccharum Officinarum ◽  
Seed Infection ◽  
Subsequent Growth ◽  
A Minor

Abstract A description is provided for Phoma insidiosa. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Sorghum spp., Oryza sativa, Saccharum officinarum, Setaria, Triticum aestivum and Zea mays. DISEASE: A minor leaf spot of Sorghum and Setaria spp. and other Gramineae. The macroscopic symptoms are variable and not particularly distinctive. Leaf lesions have an irregular outline, sometimes beginning at the tip or edge, and are brown to grey with narrow redish-purple margins. The scattered pycnidia occur sometimes in clusters or lines, interveinally. Spotting and pycnidia form on grain and glumes. GEOGRAPHICAL DISTRIBUTION: Argentina, Australia (W.), Brazil, Canada, China, Cuba, Ethiopa, Hawaii, India, Jamaica, Kenya, Laos, Malawi, Malaysia (W.), Nepal, Nigeria, Puerto Rico, Rhodesia, Senegal, Sierra Leone, South Africa, Sudan, Tanzania, Uganda, USA, USSR, Venezuela, Zaire Republic, Zambia. The fungus may be detected on introduced seed. TRANSMISSION: Probably carried on the seed; infection of the seed reduces both germination and subsequent growth. May remain viable on seed for 1 yr.

Sorosporium saponariae. [Descriptions of Fungi and Bacteria].

1988 ◽  
Author(s):  
J. E. M. Mordue
Keyword(s):  
North America ◽  
South America ◽  
Southern Hemisphere ◽  
Geographical Distribution ◽  
Contaminated Soil ◽  
Systemic Infection ◽  
Seed Transmission ◽  
Floral Organs ◽  
Soil P

Abstract A description is provided for Sorosporium saponariae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Dianthus and Saponaria spp. and other members of the Caryophyllaceae including Arenaria, Cerastium, Lychnis, Minuartia, Moehringia, Petrorhagia, Silene, Stellaria and Tunica spp. DISEASE: Flower smut of the Caryophyllaceae.GEOGRAPHICAL DISTRIBUTION: Africa: Algeria, Morocco. Asia: USSR (Caucasia, Siberia, Turkestan). Australasia: Australia (33, 634). Europe: widespread, including Austria, Bulgaria, Czechoslovakia, Denmark, Finland France, Germany, Hungary, Italy, Norway, Poland, Romania, Spain, Sweden, Switzerland, Yugoslavia. North America: USA. South America: Argentina, Chile (33, 634). Southern hemisphere records are infrequent. TRANSMISSION: No detailed studies have been reported. Floral organs, including ovules, frequently develop in infected flowers (55, 3947), therefore seed transmission is probable, with systemic infection established in seedlings from either this source or contaminated soil.

Ascochyta desmazieresii. [Descriptions of Fungi and Bacteria].

1980 ◽  
Author(s):  
E. Punithalingam
Keyword(s):  
Geographical Distribution ◽  
Leaf Spot ◽  
Crop Residues ◽  
Lolium Multiflorum ◽  
Leaf Tissue ◽  
Lower Side ◽  
Soil P ◽  
Wet Weather ◽  
Irish Republic

Abstract A description is provided for Ascochyta desmazieresii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Lolium multiflorum and L. perenne. DISEASE: Glume and leaf spot of Italian and perennial ryegrasses. At first leaf lesions start as small purplish or chocolate-brown spots with a distinct red-purple margin. With time these enlarge, become irregular or elliptical, up to 5 mm long and distinctly visible on both sides of the leaves. Finally the centres of older lesions fade to fawn to straw yellow with numerous pycnidia immersed within the leaf tissue on both sides of the leaves but usually abundant pycnidia occur on the lower side. GEOGRAPHICAL DISTRIBUTION: Asia (Japan); Europe (Belgium, Czechoslovakia, Denmark, France, Irish Republic, UK); N. America (USA, California, Oregon, Washington); S. America (Chile, Brazil). TRANSMISSION: No specific studies reported; infection is presumably spread by air-borne conidia in wet weather or heavy dews. The fungus is also probably carried over on crop residues and debris in soil.

Gaeumannomyces graminis var. tritici. [Descriptions of Fungi and Bacteria].

1973 ◽  
Author(s):  
J. Walker
Keyword(s):  
Geographical Distribution ◽  
Root Hairs ◽  
Seed Transmission ◽  
Gaeumannomyces Graminis ◽  
Root Infection ◽  
Root Death ◽  
Meristematic Region ◽  
Germ Tubes ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Abstract A description is provided for Gaeumannomyces graminis var. tritici. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Gramineae, especially Triticum, Hordeum, Secale, Agropyron and several other grass genera and, more rarely, Sorghum and Zea; also recorded from the roots of plants in other families. DISEASE: Take-all of cereals and grasses (also referred to as deadheads or whiteheads, pietin and pied noir (France), Schwarzbeinigkeit and Ophiobolus Fusskrankheit (Germany), Ophiobolusvoetziekt (Netherlands) and others). Root infection is favoured by soil temperature from 12-20°C (Butler, 1961). Ascospore germ tubes penetrate root hairs and the epidermis in the meristematic region (Weste, 1972) leading to plugging of xylem and root death. GEOGRAPHICAL DISTRIBUTION: (CMI Map 334, ed. 3, 1972). Widespread, especially in temperate zones. Africa; Asia (India, Iran, Japan, USSR): Australasia and Oceania; Europe; North America (Canada, USA); South America (Argentina, Brazil, Chile, Colombia, Uruguay). TRANSMISSION: In soil on infected organic fragments, as runner hyphae on roots of cereals and grasses and, under special conditions, by ascospores. Seed transmission very doubtful (47, 3058).

scholarly journals Importance of Different Pathways for Maize Kernel Infection by Fusarium moniliforme

1997 ◽  
Vol 87 (2) ◽  
pp. 209-217 ◽  
Author(s):  
G. P. Munkvold ◽  
D. C. McGee ◽  
W. M. Carlton
Keyword(s):  
Fusarium Moniliforme ◽  
Field Experiments ◽  
Systemic Infection ◽  
Seed Transmission ◽  
Maize Hybrids ◽  
Systemic Movement ◽  
Kernel Infection ◽  
Important Pathway ◽  
Infection Pathways ◽  
Systemic Development

The relative importance of several infection pathways (silks, stalks, and seed) leading to kernel infection of maize hybrids by Fusarium moniliforme was investigated in field experiments in 1993 and 1994. Systemic movement of specific fungal strains within plants was detected by using vegetative compatibility as a marker. Transmission of F. moniliforme from inoculated seed to stalks and developing kernels was detected in two of three field experiments; the seed-inoculated strain was detected in kernels on approximately 10% of ears. The percentage of kernels infected with the seed-inoculated strain ranged from 0 to 70%, with a mean of 0 to 2.5% (0 to 8.3% of F. moniliforme-infected kernels). Other pathways to kernel infection were more effective than seed transmission and systemic infection. F. moniliforme strains inoculated into the crowns and stalks of plants were found throughout the stalks and in up to 95% of the kernels in individual plants. Infection through the silks was clearly the most effective pathway to kernel infection. This was the only inoculation method that significantly increased overall incidence of F. moniliforme infection in kernels; the silk-inoculated strain infected up to 100% of the kernels in individual ears, with a treatment mean as high as 83.7% of kernels. When plants were silk-inoculated, the percentage of kernels infected by other F. moniliforme strains from the seed or stalk was reduced, apparently due to competition among strains. This study provides evidence that systemic development of F. moniliforme from maize seed and stalk infections can contribute to kernel infection, but silk infection is a more important pathway for this fungus to reach the kernels.

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