Trichometasphaeria turcica. [Descriptions of Fungi and Bacteria].

IMI Descriptions of Fungi and Bacteria ◽

10.1079/dfb/20056400304 ◽

1971 ◽

Author(s):

M. B. Ellis

Keyword(s):

Zea Mays ◽

Saudi Arabia ◽

Geographical Distribution ◽

Leaf Blight ◽

Diurnal Periodicity ◽

Northern Leaf Blight ◽

Setosphaeria Turcica ◽

Seedling Infection

Abstract A description is provided for Trichometasphaeria turcica[Setosphaeria turcica]. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Zea mays, Sorghum spp., Euchlaena mexicana and other Gramineae (RAM 41: 40). DISEASE: Northern leaf blight of maize and sorghum forming larger and fewer lesions than Cochlioholus heterostrophus (CMI Descript. 301), mostly on the leaves. They begin as small, dark, water-soaked areas, becoming irregular or elliptical, sometimes linear, brown then straw coloured or greyish, with red-purple or tan borders, often 4 × 10 cm or larger, coalescing and leading to death of leaves. Tassel infection on maize is less conspicuous, ear and crown rots and seedling infection occur (16: 450; 34: 716). GEOGRAPHICAL DISTRIBUTION: Widespread (CMI Map 257, ed. 3, 1968). Additional records not yet mapped are: Australia (NT), Cameroon, Ecuador, Fiji, Haiti, Indonesia, Iraq, Lebanon, Pakistan (E.) and Saudi Arabia. TRANSMISSION: Air-dispersed, probably violently discharged conidia and showing a diurnal periodicity with a forenoon max. (45, 795; 46, 114). The fungus occurs in seed and survives in host debris (15: 289; 19: 602).

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Identification and Genetic Diversity of Formae Speciales of Setosphaeria turcica in China

Plant Disease ◽

10.1094/pdis-06-14-0570-re ◽

2015 ◽

Vol 99 (4) ◽

pp. 482-487 ◽

Cited By ~ 6

Author(s):

L. Tang ◽

Z. G. Gao ◽

Y. Yao ◽

X. Liu

Keyword(s):

Genetic Diversity ◽

Polymerase Chain Reaction ◽

Geographical Distribution ◽

Leaf Blight ◽

Pcr Analysis ◽

Northern Leaf Blight ◽

Chain Reaction ◽

Setosphaeria Turcica ◽

Formae Speciales ◽

Polymerase Chain

Setosphaeria turcica is an important pathogen that causes northern leaf blight of corn and sorghum. In total, 188 isolates were isolated from diseased leaves of maize and sorghum in China. However, differences in morphology were not apparent among S. turcica isolates derived from different hosts. The formae speciales were identified as S. turcica. f. sp. zeae and S. turcica. f. sp. sorghi. Universally primed polymerase chain reaction (UP-PCR) analysis led to the conclusion that genetic differences were present among these formae speciales and divided these isolates into five clades. The isolates of each clade belonged to the same forma specialis, and different formae speciales were assigned to different clades. The results of the present study demonstrated that pathogenic specialization of the S. turcica isolate correlated more closely with genetic diversity than geographical distribution. Therefore, combined with assays for pathogenicity, UP-PCR analysis yields an enhanced understanding of the formae speciales of S. turcica.

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Khuskia oryzae. [Descriptions of Fungi and Bacteria].

IMI Descriptions of Fungi and Bacteria ◽

10.1079/dfb/20056400311 ◽

1971 ◽

Author(s):

A. Sivanesan

Keyword(s):

Zea Mays ◽

Oryza Sativa ◽

Geographical Distribution ◽

Saccharum Officinarum ◽

Diurnal Periodicity ◽

Western Hemisphere ◽

Plant Debris ◽

Stalk Rot ◽

Rare Phenomenon ◽

The Tropics

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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Cochliobolus heterostrophus. [Descriptions of Fungi and Bacteria].

IMI Descriptions of Fungi and Bacteria ◽

10.1079/dfb/20056400301 ◽

1971 ◽

Author(s):

M. B. Ellis

Keyword(s):

Zea Mays ◽

Geographical Distribution ◽

Leaf Sheath ◽

Leaf Blight ◽

Disease Spread ◽

Cochliobolus Heterostrophus ◽

Sorghum Vulgare ◽

Main Host ◽

The Tropics ◽

Diffuse Lesion

Abstract A description is provided for Cochliobolus heterostrophus. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Generally on leaves of Zea mays, the main host, Euchlaena mexicana, Sorghum vulgare and many species of Gramineae (41: 40; 45, 3084; 48, 414; 50, 2257i). During an epidemic in USA caused by race T in 1970 no important hosts apart from Z. mays were noted (50, 2257b). DISEASE: Southern leaf blight of maize, forming very numerous lesions up to 2.5 cm long, mostly on the leaves. They are at first elliptical, then longitudinally elongate, becoming rectangular as restriction by the veins occurs; cinnamon-buff (sometimes with a purplish tint) with a reddish-brown margin and occasionally zonate, coalescing and becoming greyish with conidia. Symptoms caused by race T show a less well defined, somewhat diffuse lesion, with marginal chlorosis leading to leaf collapse, and all parts of the plant can be attacked. Perithecia have been recently reported in the field at the junction of leaf sheath and blade (50, 2257j). GEOGRAPHICAL DISTRIBUTION: Widespread in the tropics and subtropics (CMI Map 346, ed. 3, 1969) but not reported from Australia. Records not yet mapped are: Brunei, Guatemala, Hawaii, Israel, Laos, Mexico, Salvador and Venezuela. TRANSMISSION: Presumably air-dispersed but no detailed studies seem to have been reported. During the recent USA outbreak the disease spread from Florida to Maine in c. 6 months (50, 2257c). Spread by seed occurs (50, 3690, 3692; Crosier & Boothroyd, Phytopathology 61: 427, 747).

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