Species Of Helminthosporium Research Articles

A New Storage Disease of Chillies (Capsicum annuum L.)

Chillies or Green peppers (Capsicum annuumL.) are extensively grown in this country during rainy and winter seasons. The crop brings good profit for the grower as it is widely used in green as well as in dried condition. A fruit spot disease of this valuable vegetable was noticed during the cold months of 1962 at Phule Market, Poona, on the sweet variety (which is usually bigger in size), stored in bamboo baskets and crates. On microscopical examination of such spots the fungus appeared to be a species of Helminthosporium. The pungent varieties of chilies such as‘Gauran’(long in size) and‘Dharwar round’wert; found to be free from infection. Affected fruits incubated in moist chambers gave abundant sporulation of the causal organism. Ripened and red chili-fruits were free from such infection in the markets. The present paper gives an account of the etiology of the disease, pathogen city and cultural behaviour of the fungus.

Growth, sporulation and conidial characteristics of five graminicolous species of Helminthosporium: I. Effect of nutrients

The pH, asparagine concentration and (especially) nitrogen source all significantly affected growth, sporulation and morphology, colour and dimensions (particularly length) of conidia produced by Helminthosporium rostratum Drechsler, H. sorghicola Lefebvre & Sherwin, H. cynodontis Marigoni, H. hawaiiense Bugnicourt and H. australiense Bugnicourt in culture. The optimum for vegetative growth was often about 0–04 % nitrogen as asparagine and that for sporulation somewhat lower (0–02%), but H. australiense and H. hawaiiense had higher optima. Conidia tended to be shorter with increasing nitrogen. Potassium nitrate, asparagine, glycine and urea were with some exceptions suitable for growth, but ammonium nitrate, ammonium sulphate, sodium nitrite, methionine and lysine resulted in poor growth, in some cases probably due to marked acidification of the medium. Nitrogen source greatly affected the size of conidia, mean length in H. rostratum ranging from 75 μ with methionine to 115 μ with sodium nitrite. Maximum growth generally occurred on neutral to slightly acid media and maximum sporulation at a somewhat lower pH, but H. rostratum, H. hawaiiense and H. australiense seemed more tolerant of alkalinity than the other two species. The longest conidia usually developed at neutrality or slight acidity. Conidial variation in culture was mostly within the range occurring in nature, except that sodium nitrite produced greater variation in length.

Saprophytic ability of species of Helminthosporium

Helminthosporium sativum, H. rostratum and H. bicolor were tested for their saprophytic ability in colonizing wheat straws in unsterilized soil by a direct observation method. Straws placed on unsterilized soil were loosely covered with the same soil so that at places the straws were visible. The soil was maintained at its moisture holding capacity and inoculum was provided in the form of 4 mm. disks from young colonies. All three species spread and sporulated well on straws in contact with soil. H. bicolor spread over the adjacent soil and sporulated on and between soil particles; in H. rostratum the spread of the mycelium to soil was restricted. H. sativum a slow growing and heavily sporulating species, spread only over the straws, sporulating when it came in contact with soil.

MICROORGANISMS IN THE ROOT ZONE IN RELATION TO SOIL MOISTURE.

The influence of soil moisture on the microbial population of rhizosphere soil and of the root surface (rhizoplane) of wheat was studied under controlled conditions. Fertile soil adjusted to 30%, 60%, and 90% of its moisture-holding capacity was used. Bacterial counts and numbers of specific "physiological groups" of bacteria all increased in the rhizosphere and the rhizoplane as soil moisture decreased. Taxonomic studies of the bacteria isolated from the rhizoplane showed a marked preponderance of species of Pseudomonas under conditions of low and intermediate soil moisture content. On the other hand species of Arthrobacter, Bacillus, and Cytophaga dominated the population at high soil moisture. Although the distribution of fungi on the roots was very similar for the low and intermediate moisture levels, there was some restriction of colonization at the high level. Species of Mortierella, Rhizopus, Chaetomium, Curvularia, and Helminthosporium were not represented among isolates from roots at high soil moisture and the relative incidence of species of Fusarium and Phoma decreased. However, high soil moisture favored root colonization by species of Rhizoctonia and sterile dark fungi.

Some graminicolous fungi associated with spotting of banana leaves in Jamaica

SUMMARYA dense spotting of leaves of young Lacatan banana plants is reported; the diameter of individual lesions rarely exceeds 2 mm. The disease is common near grassland or sugar‐cane but rare in grass‐free areas removed from sugar‐cane. Although widespread throughout Jamaica, it appears to be of negligible economic importance. Direct microscopic examination of lesions, spore‐trapping, isolation work and pathogenicity tests show that Cochliobolus sp. (?C. heterostrophus), Curvularia lunata and C. geniculata, and several species of Helminthosporium are associated with the disease and that spores of these fungi are regular components of the air‐spora in the vicinity of spotted banana leaves. The evidence suggests that grasses and sugar‐cane are major sources of inoculum. Other spots are caused by Detghtoniella torulosa which sporulates abundantly on decaying banana leaves.

Effects of Carbon and Nitrogen Nutrition on Growth and Sporulation of Two Species of Helminthosporium

Effects of Carbon and Nitrogen Nutrition on Growth and Sporulation of Two Species of Helminthosporium

Studies on hyphomycetes—I

Taxonomic notes on some interesting Hyphomycetes are presented in this paper. On the basis of study of type material of three species ofHelminthosporium (H. obclavatulum Bubak and Sydow,H. bombycinum Speg. andH. polyphragmium H. and P. Sydow),H. obclavatulum is removed toSporidesmium asS. obclavatulum (Bubak and Sydow) comb. nov.;Helminthosporium bombycinum is placed in the genusOrmathodium asO. bombycinum (Speg.) comb. nov.;Helminthosporium polyphragmium is considered to be a synonym ofCorynespora cassiicola (Berk. and Curt.) Wei. Type material of two species ofClasterosporium (C. densum H. and P. Sydow, andC. degenerans H. and P. Sydow) was also studied. Both species are described in detail.C. densum is a dematiaceous fungus producing dictyospores acrogenously and singly on conidiophores which have conspicuous annellations; further, the mycelium of this species is not hyphopodiate.C. densum is, therefore, considered distinct from the genusClasterosporium (which has hyphopodiate mycelium and produces phragmospores) and placed in a new genusAnnellophorella asA. densa (H. and P. Sydow) comb. nov.Clasterosporium degenerans is a moniliaceous fungus with hyaline mycelium and hyaline dictyospores; the mycelium is not hyphopodiate. These features exclude this fungus from the genusClasterosporium. It is made the type of a new genus,Hyalodictys and the new combination,H. degenerans (H. and P. Sydow) Subram. is proposed. A dematiaceous phragmospored fungus found in association withHelminthosporium polyphragmium Sydow in the type material of this species was also studied and is considered to be aSporidesmium; it appears to be distinct from species of this genus so far known and is given a new name,Sporidesmium camelliae-japonicae.

Studies on graminicolous species of Helminthosporium: I. H. phlei (Graham) comb.nov.

Since Drechsler (1923) published the results of his studies on some graminicolous species of Helminthosporium , no one has studied in detail a large number of species on grasses at the same time. In some species there is a great variation in dimensions and other characters under different environmental conditions. Especially variable are those species which produce their conidia in chains. In this paper one of these variable species is described in detail. Later papers will deal with several other species.

A Correlation of Interspecific Fertility and Conidial Morphology in Species of Helminthosporium Exhibiting Bipolar Germination

Of 8124 attempted interspecific crosses between 174 isolates of 16 species of Helminthosporium exhibiting bipolar germination, 47 produced viable ascospores and 24 produced sterile asci. The 16 spe...

A Correlation of Interspecific Fertility and Conidial Morphology in Species of Helminthosporium Exhibiting Bipolar Germination

A Correlation of Interspecific Fertility and Conidial Morphology in Species of Helminthosporium Exhibiting Bipolar Germination

Three leaf diseases of young oil palms associated with Helminthosporium spp.

Observations on pre-nursery and nursery oil palms in the Belgian Congo have resulted in the identification of three, previously unreported, leaf diseases which have been tentatively named ‘Eye Spot’, ‘Leaf Rot’ and ‘Leaf Speckle’. Eye Spot and Leaf Rot are allied in that they appear together in the pre-nursery, and double infection of the seedlings is of common occurrence. Eye Spot is caused by Helminthosporium carbonum whilst Leaf Rot is associated with the Helminthosporium state of Cochliobolus heterostrophus . Nurseries and pre-nurseries are commonly established on recently cleared forest and it has been observed that both these fungi are associated with diseases of Sarcophrynium arnoldianum (Marantaceae), a plant usually present in the re-growth of cleared forested areas. This host is believed to be a common source of infection for Eye Spot and Leaf Rot of the oil palm. Leaf Speckle has been shown to be caused by a suspected new species of Helminthosporium .

An Undescribed Species of Helminthosporium on Sudan Grass and Sorghum

An Undescribed Species of Helminthosporium on Sudan Grass and Sorghum

An Undescribed Species of Helminthosporium on Sudan Grass and Sorghum

In 1939, G. W. Burton collected and sent us (7) leaves of a common Sudan grass x Leoti sorghum hybrid (now Tift Sudan grass), bearing a leaf that was defoliating some of his breeding material. Lesions on these leaves varied considerably, the smaller ones being 0.5 to 1.0 mm. in each direction, whereas the longer ones measured up to 15 mmn. in length and 1 to 6 mm. in width. The lesions were round to elliptical, the long axis parallel to the leaf veins, and oftentimes the spots seemed to be limited in their spread by the veins. Many of the lesions had coalesced so that comparatively large portions of the leaves were affected (FIG. 1, A). The most characteristic features of the lesions, however, were the alternate light tan and darker, more narrow bands of tissue, producing a zonate appearance which suggests the common name spot (FIG. 1, A). Lesions were usually surrounded by a narrow tannish-brown border setting off the affected area from the healthy tissue. The symptoms on Tift Sudan grass are strikingly similar to the lesions on corn and teosinte caused by the fungus originally described as Ophiobolus heterostrophus Drech. (5), but later transferred to the genus Cochliobolius (6). Although the fungus causing the target of Tift Sudan grass has never been collected on common Sudan grass, the latter was found to be susceptible when inoculated. On common Sudan, however, the lesions appear less zonate (FIG. 1, B). The spots are often uniformly dark, or when older they may have a strawcolor center surrounded by a reddish-purple border; others have an additional band of straw-color tissue that in turn is surrounded by a dark border. The striking difference in the leaf spots of the two varieties of Sudan grass is in the color because Tift Sudan

STUDIES ON ROOT ROT OF CORN IN ONTARIO

Root rot of corn in Ontario is caused primarily by parasitic soil micro-organisms, the most important of which are species of Pythium, Helminthosporium, and Fusarium in that order. The disease causes a decrease in the stand by pre-emergence killing and a dwarfing of the plants by the parasitic invasion and destruction of their roots by the organisms. The pathogens have different optimum soil temperatures but the lower ranges favour those that cause the most severe damage. The roots of other field crops can be parasitized by the organisms found associated with corn root rot, but their effect on the development of the crop varies greatly. It has been proved under greenhouse conditions that the severity of the disease is greatly reduced if the corn is preceded by cover crops of soybeans and materially increased when preceded by timothy. Other crops tested have an intermediate effect.

Studies in the biochemistry of micro-organisms

Research Article| September 01 1941 Studies in the biochemistry of micro-organisms: Synthesis of catenarin (1:4:5:7-tetrahydroxy-2-methylanthraquinone), a metabolic product of species of Helminthosporium Winston Kennay Anslow; Winston Kennay Anslow 1The Division of Biochemistry, London School of Hygiene and Tropical Medicine, University of London Search for other works by this author on: This Site PubMed Google Scholar Harold Raistrick Harold Raistrick 1The Division of Biochemistry, London School of Hygiene and Tropical Medicine, University of London Search for other works by this author on: This Site PubMed Google Scholar Biochem J (1941) 35 (8-9): 1006–1010. https://doi.org/10.1042/bj0351006 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation Winston Kennay Anslow, Harold Raistrick; Studies in the biochemistry of micro-organisms: Synthesis of catenarin (1:4:5:7-tetrahydroxy-2-methylanthraquinone), a metabolic product of species of Helminthosporium. Biochem J 1 September 1941; 35 (8-9): 1006–1010. doi: https://doi.org/10.1042/bj0351006 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Journal Search Advanced Search This content is only available as a PDF. © 1941 CAMBRIDGE UNIVERSITY PRESS1941 Article PDF first page preview Close Modal You do not currently have access to this content.

Two diseases of grasses caused by species of Helminthosporium not previously recorded in Britain

Summary Two species of Helminthosporium are recorded for the first time in Britain, H. siccans Drechsler on Lolium perenne, L. multiflorum and Festuca pratensis and Helminthosporium vagans Drechsler on Poa pratensis . Monospore cultures of both species have been studied. Certain isolates of H. siccans showed slight but consistent variations in cultural characters and in the size and shape of the conidia.

Species of Helminthosporium and Curvularia associated with root-rot of wheat and other graminaceous plants

Species of Helminthosporium and Curvularia associated with root-rot of wheat and other graminaceous plants

Studies in the biochemistry of micro-organisms

Research Article| January 01 1934 Studies in the biochemistry of micro-organisms: (a) On the production of hydroxyanthraquinones by species of Helminthosporium. (b) Isolation of tritisporin, a new metabolic product of Helminthosporium tritici-vulgaris Nisikado. (c) The molecular constitution of catenarin Harold Raistrick; Harold Raistrick 1The Division of Biochemistry, London School of Hygiene and Tropical Medicine, University of London, and the Dyson Perrins Laboratory, Oxford University Search for other works by this author on: This Site PubMed Google Scholar Robert Robinson; Robert Robinson 1The Division of Biochemistry, London School of Hygiene and Tropical Medicine, University of London, and the Dyson Perrins Laboratory, Oxford University Search for other works by this author on: This Site PubMed Google Scholar Alexander Robertus Todd Alexander Robertus Todd 1The Division of Biochemistry, London School of Hygiene and Tropical Medicine, University of London, and the Dyson Perrins Laboratory, Oxford University Search for other works by this author on: This Site PubMed Google Scholar Biochem J (1934) 28 (2): 559–572. https://doi.org/10.1042/bj0280559 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share MailTo Twitter LinkedIn Cite Icon Cite Get Permissions Citation Harold Raistrick, Robert Robinson, Alexander Robertus Todd; Studies in the biochemistry of micro-organisms: (a) On the production of hydroxyanthraquinones by species of Helminthosporium. (b) Isolation of tritisporin, a new metabolic product of Helminthosporium tritici-vulgaris Nisikado. (c) The molecular constitution of catenarin. Biochem J 1 January 1934; 28 (2): 559–572. doi: https://doi.org/10.1042/bj0280559 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Journal Search Advanced Search This content is only available as a PDF. © 1934 CAMBRIDGE UNIVERSITY PRESS1934 Article PDF first page preview Close Modal You do not currently have access to this content.

THE NATURE OF SALTATION IN CERTAIN SPECIES OF HELMINTHOSPORIUM AND FUSARIUM

Journal Article THE NATURE OF SALTATION IN CERTAIN SPECIES OF HELMINTHOSPORIUM AND FUSARIUM Get access SYDNEY DICKINSON SYDNEY DICKINSON CAMBRIDGE Search for other works by this author on: Oxford Academic PubMed Google Scholar Annals of Botany, Volume os-47, Issue 4, October 1933, Pages 920–921, https://doi.org/10.1093/oxfordjournals.aob.a090427 Published: 01 October 1933

On Some New Ascigerous Stages of the Species of Helminthosporium Parasitic on Cereals

On Some New Ascigerous Stages of the Species of Helminthosporium Parasitic on Cereals