An evaluation of corn lines and seed condition in the cold test

Call number: LD2668 .T4 1951 C85Master of Scienc

BROWN SPOT CAUSED BY CURVULARIA SPP., A NEW DISEASE OF ASPARAGUS

The distribution, aetiology and symptomatology of a new disease on asparagus ferns, which we have termed brown  spot,  is  described.  Descriptions  of  and  a  key  to  identification  of  the  causal  organisms,  Curvularia brachyspora, C. eragrostidis, C. lunata and C. pallescens, are also presented. Pathogenicity tests showed that C. lunata was the dominant and most virulent of the four species. Inoculation with conidial suspensions or mycelial transfers through wounded ferns were more effective in inducing the disease than inoculations on unwounded ferns. This is the first record of C. brachyspora in Malaysia and the first report of this disease on asparagus.Key words:  Malaysia/Plant diseases/Brown spotJCurvularia brachyspora/Curvularia eragrostidts/Curvularia lunata/Curvularia pallescens/Asparagus

A Pictorial Guide for the Identification of Mold Fungi on Sorghum Grain

Sorghum is one of the main staple food crops of the world's poorest and most food-insecure people. Approximately 90% of the world's sorghum areas are located in Africa and Asia. During 1992-94, 42% of the total sorghum produced worldwide was utilized for food, and 48% for animal feed. A preliminary study was conducted to understand the various storage conditions of sorghum grain, and the potential occurrence of mold fungi under such conditions. A total of 67 sorghum grain samples were collected from two surveys, 15 samples from the 1996 rainy season harvest, and 11 from the 1996/97 postrainy season harvest collected in June 1997, and 19 samples from the 1996/97 postrainy season and 22 from 1997 rainy season harvest collected in October 1997. Approximately 1 kg grain from each of the grain lots stored under various conditions (gunny bags, mud-lined baskets, metallic containers, polypropylene bags, and grains piled in a corner of a room) by farmers in rural India was collected. Each grain sample (200 grains treatment1) was examined to identify fungi up to the species level. Grains with and without surface sterilization were transferred separately to pre-sterilized petri dish humid chambers under aseptic conditions. The petri dishes were incubated for 5 days at 28±1 °C in an incubator with a 12-h light cycle. Under each treatment, 200 grains (25 grains dish-1) were examined for 49 mold fungi, including the species of Aspergillus and Penicillium. The major fungi observed on the grains included species of Alternaria, Curvularia, Drechslera, Fusarium, and Rhizopus. The frequency of occurrence of the various fungi on each grain sample under the various treatments was analyzed. This bulletin reports some new mold fungi on sorghum grain in India: Alternaria longipes, Bipolaris zeicola, Curvularia affinis, C. clavata, C. fallax, C. geniculata, C. harveyi, C. ovoidea, C. pallescens, C. tuberculata, Drechslera halodes, Gonatobotrys simplex, Nigrospora oryzae, Periconia macrospinosa, Spadicoides obovata, Torula graminis, and Trichothecium roseum

Pragmatic approach to subject indexing: A new concept

In 1982 it was decided to computerize the indexing activities of SMIC—the Sorghum and Millets Information Center—located in the Library of ICRISAT (International Crops Research Institute for the Semi-Arid Tropics). The previously used manual indexing procedure was found to be unsuitable for computer manipulation, and it was decided to replace it by some other system which would be computer-manipulative and could represent subject contents of the documents accurately and precisely. A survey of the existing systems was made and none of them was found entirely satisfactory for SMIC. A simple indexing system has been developed which is free from any classification system and which is not limited by cumbersome postulates. In this system, keywords chosen by the indexer (who is expected to have some subject knowledge) are arranged in a meaningful sequence (a logical string). The keywords are connected by punctuation marks depicting various types of associations. The keywords are rotated to provide access through each significant keyword. The system, which is computer-manipulative, can also be used manuall

Black Kernel and White Tip of Rice.

14 p

Phenotypic and molecular characterization of clinical isolates of bipolaris, curvularia, exserohilum and pithomyces

The generaBipolaris, Curvularia, Exserohilium and Pithomyceshave species clinically relevant.However, their identification is not easy. A total of 281 clinical isolates of Bipolaris,Curvularia,ExserohilumandPithomyceshave been studied by morphological and molecular methods. The in vitrosusceptibility studies of these genera were performed against the different antifungal drugs availables. Our studies revealed the presence of many species of Bipolaris, Curvularia and Pithomyces species can be isolated from human specimens; we proposed five new species ofCurvularia such as C. americana, C. chlamydospora, C. hominis, C. muehlenbeckiae and C. pseudolunata.Our phylogenetic analysis revealed that only E. rostratum should be considered as human opportunist. Evaluation of the in vitro antifungal susceptibility profile revealed that most of the antifungal drugs tested presented a good activity against the genera studied.Bipolaris, Curvularia, Exserohilumand Pithomycesson agentes responsables de infecciones oportunistas.El gran número y lasemejanza morfológicaentre las especies en estos géneros dificultan su identificación. Se han estudiadoun total de 281 cepasde Bipolaris, Curvularia, Exserohilum y Pithomyces por métodos morfológicos y moleculares además dela susceptibilidad in vitro de los mismo frente alos antifúngicos. Los resultados obtenidos demuestran la presencialas siguientes especies:Bipolariscynodontis, B. micropus, B. setariae, Curvulariaaeria, C. borreriae, C. intermedia, C. protuberata, C. pseudorobusta,C. sorghina, Pithomycessacchariy P. maydicus,por primera vez en muestras clínicas, además de las 5 nuevas especies de Curvularia. Nuestro análisis filogenético ha demostrado que del género Exserohilum sólo E. rostratum debe de ser considerada como un patógenooportunista. Laevaluación del patrón de susceptibilidad antifúngicaha evidenciado que la mayoría de antifúngicosensayados presentan una buena actividad frente a las distintas especies estudiadas

Nota Corta: Endophytic fungi in healthy soybean leaves

SUMMARY Fungal endophytes were isolated from healthy cultivated soybean leaves at two growth stages (R2-R3 and R4-R5) during the growing season 1997/98. Samples were obtained from a segregating population (F 3 generation) cultivated at the experimental field of the Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, Buenos Aires, Argentina. Twelve genera of endophytic fungi were isolated and identified. In general, in both growth stages the same species were isolated and most of them did not show significant differences in their infection frequencies. Most of the fungi isolated are cited as soybean pathogens in different places of the world. The most commonly isolated endophytes included Alternaria alternata and Glomerella cingulata (= Colletotrichum gloeosporioides). Key words: endophytes, Glycine max Endophytes are fungi that form inapparent infections within leaves and stems of healthy plant

Plant pathogenic Magnaporthales in Australia, with particular reference to Pyricularia oryzae on wild and cultivated rice

The Magnaporthales is an order of fungi that contains plant pathogens and saprobes. This order consists of three families, Pyriculariaceae, Magnaporthaceae and Ophioceraceae, which are phylogenetically, morphologically and ecologically distinct. To date, about 200 species have been described in Magnaporthales, of which approximately 50% are plant pathogens. Some species are important pathogens of grasses and cereals such as the rice blast fungus Pyricularia oryzae (syn. Magnaporthe oryzae) and the take-all pathogen of cereals Gaeumannomyces graminis. The study of classification and identification of Magnaporthales in Australia and pathogenicity of Pyricularia oryzae are reported in this thesis