Peronosclerospora sorghi. [Descriptions of Fungi and Bacteria].

1983 ◽  
Author(s):  
S. M. Francis
Keyword(s):  
Geographical Distribution ◽  
Primary Sources ◽  
Sorghum Halepense ◽  
Great Abundance ◽  
Peronosclerospora Sorghi ◽  
Johnson Grass ◽  
Local Lesions ◽  
Leaf Tissues ◽  
Maize Plants ◽  
Yemen Arab Republic

Abstract A description is provided for Peronosclerospora sorghi. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Panicum trypheron; Sorghum × almum, S. arundinaceum, S. bicolor, S. × drummondii, S. halepense, S. nitidum, S. verticilliflorum (= S. arundinaceum); Zea diploperrenis, Z. mays, Z. mexicana. DISEASE: Sorghum Downy Mildew (SDM); a biotrophic plant pathogen. The disease is systemic. The pathogen invades and colonizes the growing points of young graminiaceous plants. Symptoms are first seen at the base of the leaves which appear yellowish. Later symptoms are the very characteristic streaks of chlorotic tissue alternating with green which run the length of the leaf. Leaves developing later will be totally chlorotic. Conidiophores and conidia form on the undersurface of the green areas when conditions are suitable. Conidiophores do not usually form on the undersurface of chlorotic areas. Oospores form in great abundance in the chlorotic tissues which become dry and brittle. These leaf tissues eventually disintegrate and split. The oospores are released and the leaves assume the characteristic shredded appearance of this disease on sorghum but not on maize. Local lesions can be produced on otherwise non-diseased leaves of susceptible cultivars forming yellowish rectangular diseased lesions varying in size from small flecks to a spot ca. 20 × 5 mm. Asexual spores may be formed on the undersurface of local lesions but oospores have never been found in these lesions. On sorghum diseased panicles are brown and shrivelled and form no grain. Occasionally panicles occur with only the lower portion diseased. In maize the diseased tassles are severely malformed and distorted. GEOGRAPHICAL DISTRIBUTION: CMI Map 179, ed. 3, 1977. Add - Africa (Zimbabwe, as 'Rhodesia'); Asia (Iran (50, 5475), Yemen Arab Republic (60, 196); Australia (Queensland (58, 1220)); N. America (I11. (58, 2774), Neb. (59, 179); C. America (El Salvador, Guatemala, Honduras; Malaguti, 1980); S. America (Bolivia, Uruguay; Malaguti, 1980) TRANSMISSION: Initial infections can occur from oospores in the soil and also from conidial showers from infected leaves. In certain regions, i.e., Venezuela, the perennial wild grasses, Johnson grass, Sorghum halepense and S. arundinaceum, are reservoirs of infection and provide primary sources of inoculum. Oospores have not been found in Thailand in the tissues of maize plants infected by the Thai maize pathotype.

Sclerospora sorghi. [Descriptions of Fungi and Bacteria].

1975 ◽  
Author(s):  
R. Kenneth
Keyword(s):  
Geographical Distribution ◽  
Systemic Infection ◽  
Geographic Region ◽  
Transmitted Infection ◽  
Peronosclerospora Sorghi ◽  
Heteropogon Contortus ◽  
Resting Spores ◽  
Local Lesions ◽  
Systemic Infections ◽  
Sclerospora Sorghi

Abstract A description is provided for Sclerospora sorghi[Peronosclerospora sorghi]. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Sorghum bicolor, Sorghum sudanense, Sorghum almum, Sorghum halepense, maize, teosinte and, apparently, Heteropogon contortus. DISEASE: Sorghum downy mildew (SDM); both systemic and local infections occur in sorghums, in maize usually only systemic. In systemic infections, chlorotic laciniate areas extend from bases of leaf blades (half-leaf symptoms), with successive leaves displaying greater or complete chlorotic involvement. Sporulation (white down) occurs on dewy nights; conidia, actively ejected, germinate and infect immediately, inducing local lesions on sorghum leaves but seldom on maize. Resting spores form in systemically-infected plants in immense numbers within chlorotic areas (less, or sometimes not at all in maize, according to geographic region and variety) and leaves of sorghum, but not maize, later shred. Systemically infected plants tend to be dwarfed and, on many cultivars, produce few or sterile inforescences. There may be late expression of chlorotic symptoms in some plants inoculated at seedling stage. Local lesions are elongate, yellowish, then purple, with white down, finally necrotic. GEOGRAPHICAL DISTRIBUTION: Widespread (CMI Map 179 cd. 2, 1966, with some additions and deletions). Africa: Nigeria, Egypt, Sudan, Kenya, (?) Congo, Uganda, Tanzania, Rhodesia, Zambia, South Africa. Asia: Israel, (?) Iran, Pakistan, India, Thailand, Nepal, China. N. America: USA, Mexico, Honduras. S. America: Venezuela, Brazil, Peru, Argentina. TRANSMISSION: Primary infection (systemic) in USA, Israel and part of India is by resting spores (oospores) which may remain viable in soil for a number of years. Conidial-induced systemic infection in all lands occurs on plants up to 4 weeks of age. and in Thailand is apparently the principal or only mode. With oospore infection, the frst leaf is never chlorotic: with early inoculation by conidia, the frst leaf may be infected and seedlings may die. Seed-transmitted infection has been proven (49, 744), mostly by adhering oospores, but when internal hyphae are present, no transmission occurs if seed is dried before sowing (52, 1114). Local lesions are induced only by conidial inoculation. Sowing in cold soil (less than 20°C) prevents infection by oospores (50, 1765). Conidia are normally viable only a few hours after sporulation which occurs after midnight to before dawn at 18-28°C (opt. 21°C) (15-30°C with opt. 22-25°C or 24-26°C in Thailand) and transmission of disease by air-borne conidia apparently is restricted to nearby fields. Opt. for conidial infection is 21-24°C. Resting spores were reported to retain infectivity after passage through digestive tract of cattle.

Claviceps sorghi. [Distribution map].

1987 ◽  
Author(s):  
Keyword(s):  
South Africa ◽  
Sri Lanka ◽  
Geographical Distribution ◽  
Sorghum Halepense ◽  
Distribution Map ◽  
Sorghum Vulgare ◽  
Yemen Arab Republic ◽  
New Distribution

Abstract A new distribution map is provided for Claviceps sorghi Kulkarni Seshadri & Hegde. Hosts: Sorghum vulgare, Sorghum halepense and other Sorghum species. Information is given on the geographical distribution in AFRICA, Botswana, Ethiopia, Ghana, Kenya, Mozambique, Nigeria, Rwanda, Senegal, South Africa, Sudan, Tanzania, Uganda, Zambia, Zimbabwe, ASIA, Burma, India, Japan, Philippines, Sri Lanka, Thailand, Yemen, Arab Republic (North Yemen).

Population variation in Sorghum halepense, Johnson grass, at the northern limits of its range

1984 ◽  
Vol 62 (9) ◽  
pp. 1781-1790 ◽  
Author(s):  
S. I. Warwick ◽  
B. K. Thompson ◽  
L. D. Black
Keyword(s):  
New York ◽  
Dry Weight ◽  
Population Variation ◽  
Sorghum Halepense ◽  
Johnson Grass ◽  
Allocation Patterns ◽  
Cultivated Species ◽  
Relationship Of ◽  
The Relationship ◽  
Enzyme Patterns

Thirteen populations of Sorghum halepense, Johnson grass, were sampled from fields in Ontario, Canada, and Ohio and New York, United States. Only four of these populations were reported to overwinter as rhizomes. The morphology, phenology, resource allocation patterns, and growth of seedling and mature plants of the overwintering and the non-overwintering populations were compared. Field-collected specimens from the nonoverwintering populations had wider culms and leaves and larger seeds and inflorescences. Analysis of material grown in a 5-month greenhouse trial indicated similar differences. Greenhouse plants from the nonoverwintering populations were also characterized by greater percent emergence, larger and faster growing seedlings, earlier flowering, larger culms and seeds, greater reproductive dry weight per plant, and about 1/10th the rhizome dry weight of overwintering plants. Differences between populations within a biotype were evident for both biotypes, although there was little within-population variation, except in rhizome production, where certain individuals of some nonoverwintering populations did not produce extended rhizomes. Among the five enzymes which were examined electrophoretically, only one, phosphoglucomutase (PGM), showed variable isozyme patterns. No differences in enzyme patterns were apparent between the overwintering and the nonoverwintering biotypes. The relationship of the nonoverwintering populations to the cultivated species, Sorghum bicolor and S. almum, an introgressant between S. halepense and S. bicolor, is discussed.

Cercospora sorghi. [Descriptions of Fungi and Bacteria].

1974 ◽  
Author(s):  
J. L. Mulder
Keyword(s):  
Geographical Distribution ◽  
Leaf Spot ◽  
Sorghum Vulgare ◽  
Grey Leaf Spot ◽  
Sudan Grass ◽  
Leaf Colour ◽  
Black Light ◽  
Johnson Grass

Abstract A description is provided for Cercospora sorghi. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Sorghum vulgare, S. sudanense, S. halepense and S. dochna. DISEASE: Grey leaf spot of sorghum, Sudan grass, Johnson grass and broomcorn. Spots usually first form on the lower leaves and infection gradually spreads upwards; they are elongate, somewhat delimited by the veins and individually > 1 cm long and 3-5 mm in width. Coalescence can take place, to give larger stripes or patches and kill large areas of the leaf. The colour (shades of red to black, light brown or yellowish) of the lesions varies with that of leaf colour. The deep coloured spots tend to have lighter coloured outer rings than the paler ones where the margins are darker. Colours darken with age and a faint zonation may be found (10, 516). GEOGRAPHICAL DISTRIBUTION: Widespread (CMI Map 338, ed. 3, 1974). TRANSMISSION: No studies reported; conidia presumably air-dispersed and spread from host debris.

scholarly journals First Report of Pyricularia oryzae Causing Blast on Sorghum halepense (Johnson Grass) in Iran

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 3061-3061
Author(s):  
Adel Pordel ◽  
Didier Tharreau ◽  
Golzar Ghorbani ◽  
Mohammad Javan-Nikkhah
Keyword(s):  
Pyricularia Oryzae ◽  
Sorghum Halepense ◽  
First Report ◽  
Johnson Grass

Ramulispora sorghicola. [Descriptions of Fungi and Bacteria].

1978 ◽  
Author(s):  
K. H. Anahosur
Keyword(s):  
Sorghum Bicolor ◽  
Geographical Distribution ◽  
Wild Species ◽  
Leaf Spot ◽  
Lower Surface ◽  
Infected Leaf ◽  
Small Water ◽  
Leaf Tissues ◽  
Upper Volta

Abstract A description is provided for Ramulispora sorghicola. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Sorghum bicolor, S. halepense, S. nitidum, S. vulgare, Sorghum spp. (wild). DISEASE: Leaf spot. Small water-soaked lesions develop into oval to elliptical spots up to 7 × 3 mm, delimited by veins, with dark red or tan border up to 1 mm wide. Spots become irregular by 2-3 spots coalescing, with pinkish grey to straw necrotic centres. A few black sclerotia are found on the lower surface of roots. GEOGRAPHICAL DISTRIBUTION: Africa (Ethiopia, Nigeria, Malawi, Upper Volta); Asia (India, Indonesia, Pakistan). TRANSMISSION: The fungus can survive in the fragments of infected leaf tissues which remain on the ground and produce masses of conidia in damp weather which are disseminated by rain and wind. Sclerotia also survive and produce conidia in damp weather (Harris, 1960; Tarr, 1962). Wild species of sorghum act as collateral hosts.

Setosphaeria pedicellata. [Descriptions of Fungi and Bacteria].

1986 ◽  
Author(s):  
A. Sivanesan
Keyword(s):  
South Africa ◽  
Geographical Distribution ◽  
Root Rot ◽  
Sorghum Halepense ◽  
Wheat Roots

Abstract A description is provided for Setosphaeria pedicellata. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Echinocloa, Oryza, Triticum, Zea. It can also infect Paspalum dilatum, Setaria lutescens and Sorghum halepense (46: 2000). DISEASE: The anamorph is associated with dark brown lesions on wheat roots and root rot of maize (46: 2000; 48: 1671) but is only weakly parasitic. GEOGRAPHICAL DISTRIBUTION: Egypt, India, Pakistan, USA, South Africa. TRANSMISSION: By air-borne conidia.

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