bluuebunny/crossref_metadata_2025_split huggingface dataset:
Supplementary Antimold Activity of Phosethyl AL, A New Brown Rot Fungicide for Citrus Fruits
Authors: Gutter Y. 
Published: May 2008

AbstractPhosethyl Al (= Aliette) is a new and promising postharvest fungicide against brown rot of citrus fruits. Its effectiveness in controlling green mold (Penicillium digitaum), the major citrus fruit pathogen, was studied on artificially inoculated fruit and compared with that of sodium o‐phenylphenate (SOPP) and thiabendazole (TBZ). In vitro and in vivo experiments have shown that phosethyl Al is capable — although to a lesser extent than SOPP and TBZ — of inhibiting growth of P. digitatum and reducing the incidence of decay of citrus fruits, caused by a wild‐type, and apparently also by a benzimidazole‐resistant strain of this fungus.The influence of times of treatment and modes of application (including temperature and duration of treatment, rinsing of the fruit) on the effectiveness of phosethyl Al, SOPP and TBZ in controlling green mold was studied and discussed. It is concluded that, under conditions of natural infection, phosethyl Al can be used for the postharvest control of Phytophthora‐caused brown rot without any apparent increase in the incidence of green mold in the treated fruits.
Pleospora drummondii spec. nov. und ihr Anamorph Stemphylium drummondii spec. nov.
Authors: Nirenberg H. I. , Plate H.‐P. 
Published: May 2008

AbstractPleospora drammondiispec. nov. and its anamorphStemphylium drammondiispec. nov.The causal organism of a leaf spot disease onPhlox drummondiiis described asPleospora drummondiispec. nov. and its anamorphStempbylium drummondiispec, nov. — in contrast to earlier reports from the USA, in which the fungus was identified asS. botryosum.
Scanning Electron Microscopy of Pseudomonas syringae pv, morsprunorum on Sweet Cherry Leaves
Authors: Roos Isabel M. M. , Hattingh M. J. 
Published: May 2008

AbstractScanning electron microscopy indicated that sub‐stomatal cavities on sweet cherry leaves are “protected sites” which shelter resident populations of Pseudomonas syringae pv. morsprunorum. Bacteria entered the stomata, multiplied in the cavities and emerged in a mass 6 days after inoculation. There were no visible symptoms, suggesting that the pathogen colonized the host in “sub‐clinical” numbers to generate populations which were then released onto the leaf surface under suitable conditions.
The Association of Brome Mosaic Virus and Wheat Rusts: I. Transmission of BMV by Uredospores of Wheat Stem and Leaf Rust
Authors: Erasmus D. S. , Von Wechmar M. B. 
Published: May 2008

AbstractBoth the stem and leaf rust fungi of wheat (Puccinia graminis f. sp. tritici, P. recondita f. sp. tritici) were investigated as potential vectors of brome mosaic virus (BMV), a pathogen of Gramineae. They were found to transmit BMV to healthy plants through uredospore transfer from hosts infected with both the viral and fungal pathogens. Virus was transmitted even to rust‐resistant and non‐susceptible hosts. Rust‐transmitted virus produced atypical symptoms on plants, could not be extracted by normal low pH methods, and multiplied only to low levels in leaf tissue. Extracted virus was shown to be similar to BMV‐type strain (ATC) by serology, density gradient centrifugation and immunospecific electron microscopy. The importance of the association of BMV with the rust fungus in natural infections is discussed.
The Genera and Species Spectrum of Cucumber Powdery Mildew in Czechoslovakia
Authors: Lebeda A. 
Published: May 2008

AbstractIn 1979 and 1980, the fungi causing cucumber powdery mildew were investigated in Czechoslovakia. In 37 localities in the major growing 102 samples of mildew were collected. Most of them came from cucumber leaves (especially from field cultures), few came from squash leaves. Studies of the imperfect stage served to identify, in the samples, two pathogen species, viz. Erysiphe cichoracearum and Sphaerotheca fuliginea have been found. E. cichoracearum predominated under field conditions; S. fuliginea was found in only two localities. In glasshouses S. fuliginea predominated.
Zur Rolle des Pektins bei der Ausprägung sorten‐ und jahresbedingter Unterschiede der Naßfäuleanfälligkeit von Kartoffelknollen
Authors: Weber J. 
Published: May 2008

AbstractThe influence of soil moisture and mean day temperature of July to September on pectin structure and soft rot resistance of potato tubers was investigated.Tuber samples of middle early and middle late potato cultivars respectively were tested from 1976 to 1979.Cultivar characteristics as well as growth conditions effect the pectin structure. The tuber tissue of soft rot resistant cultivars contains relative high amounts of esterified pectin. The pectin esterification was promoted by drought during vegetation periods (1976, 1978). A late rise of metabolic activity caused by rainfall at the end of the vegetation period (1978) increased the amount of soluble pectin in the cell wall. This lack of pectin stabilization facilitates tissue maceration by soft rot bacteria.Increased pectin solubility was also caused by unfavorable storing conditions of potato tubers.A low degree of esterification and high solubility of the cell wall pectin affect the relative resistance of potato tubers against soft rot caused by Erwinia carotovora var. atro‐septica (van Hall) Dye adversely.
Metabolites of Alternaria solani, Part IX: Phytotoxicity of Altersolanol A
Authors: Holenstein J. E. , Stoessl A. 
Published: May 2008

AbstractThe fungal tetrahydroanthraquinone altersolanol A has been found to exhibit nonspecific phytotoxicity to potato, tomato, pea and cress tissues, causing necrosis on leaves and inhibiting root growth.
Selection of Antagonistic Fluorescent Pseudomonas spp. and their Root Colonization and Persistence following Treatment of Seed Potatoes
Authors: Geels F. P. , Schippers B. 
Published: May 2008

AbstractOne hundred and twelve fluorescent Pseudomonas isolates from potato periderm were screened for antagonistic activity in vitro against 5 pathogenic and saprophytic fungi, 5 Gram‐positive bacteria including Streptomyces scabies and 4 Gram‐negative bacteria including Erwinia car. var. carotovora and Erwinia car. var. atroseptica. Fifty‐seven percent of the isolates showed wide spectrum inhibitory activity, mostly due to the production of fluorescent siderophores. Only 4 % of the isolates were very strong antagonists. By adding iron (Fe3+) to the test medium, the antagonistic activity drastically diminished but revealed some strong antagonists of which the antagonism was not affected. Apparently growth‐inhibiting substances other than siderophores were involved. Antibiotic‐resistant mutants of the antagonists were used to establish that the bacteria on the seed tubers migrated to the roots under different conditions. Drying of the treated potatoes gradually diminished the number of viable cells, but subsequent planting in moist soil led to substantial increases in the first three days. Initially high numbers of the antibiotic‐resistant antagonists on the roots tended to drop quickly in time, probably due to loss of resistance to the antibiotics in the selective medium.
Culturing Puccinia coronata on a Cell Monolayer of the Avena sativa Coleoptile
Authors: Mendgen K. , Dressler Elvira 
Published: May 2008

AbstractA culture of Puccinia coronata on an epidermal cell monolayer dissected from the Avena sativa caleoptile is described. To induce fungal development, infection structure formation had to be induced with a heat treatment. The host cells were fed with 1 % sucrose (or glucose or manitol) to sustain fungal growth. Under these conditions, normal development of hyphae, haustoria with haustorial mother cells and uredospores occurred. Uredospores had normal infectivity.
Reactions in Maize Infected with Swedish Isolates of Barley Yellow Dwarf (BYDV)
Authors: Eweida M. , Tomenius Karin , Oxelfelt P. 
Published: May 2008

AbstractNine cultivars of maize (Zea mays L.) were tested for susceptibility to BYDV under three temperature ranges in the greenhouse. Three Swedish isolates of BYDV were used, two specifically transmitted by Rhopalosiphum padi (L.) (39/78) and by Sitobion avenae (Fabr.) (27/77), respectively, and the third by both species (70). The virus isolates were transmitted successfully from different grasses to maize and from infected maize to the susceptible oat cultivar “Sol II” by the respective aphid species. S. avenae showed very high ability to transmit the S. avenae specific isolate to and from maize plants.The main symptoms that developed on maize were fine chlorotic irregular spots, reddish purple discoloration and malformed leaves.The relationship between maize cultivar, temperature and percent of infection is discussed. Enzyme‐linked Immunosorbent Assay (ELISA) was used with success to detect the virus isolate 27/77 in susceptible and symptomless maize plants.Electron microscopy of maize (cv. LG ll) infected with the 27/77 isolate of BYDV revealed virus‐like particles, about 22 nm in diameter, in the nuclei of companion cells, in the plasmodesmata connecting companion cells with mature sieve tubes, in the lumen of mature sieve tubes and in xylem tracheal elements.
Über die Pleomorphie von MLO in Catharanthus roseus (Vinca rosea)
Authors: Schmitt U. , Petzold H. , Marwitz R. 
Published: May 2008

AbstractAbout the pleomorphism of MLO in Catharanthus roseus (Vinca rosea) MLO of the flower greening (virescence)‐type of Primula in the phloem of Catharanthus roseus (Vinca rosea) were fixed in two different ways. After prefixation with OsO4 they showed a diminished pleomorphic morphology, most MLO were spherical. With the fixation of KARNOVSKY (1965) and subsequent treatments with OsO4 and uranyl acetate, however, an extremely high pleomorphism was observed. Such pleomorphic MLO in single thin sections are probably the expression of a threedimensional network‐like connection. The concentration of MLO in the sieve elements seems to influence the pleomorphism only insignificantly.
Common Leafspot of Alfalfa: Ascospore Germination and Disease Development in Relation to Moisture and Temperature
Authors: Semeniuk G. 
Published: May 2008

AbstractIn a moist chamber Pseudopeziza medicaginis ascospores infected alfalfa (Medi sativa L.) moderately to abundantly within 6–10 h at 10–20 °C and within a longer time‐span outside this temperature range. Approximate limits of the range were 2.5 and 28 °C; no infection took place at 30 °C. At 14°C ascospores infected alfalfa abundantly at 98 %relative humidity (RH) and above, moderately at 97%, sparsely at 95 and 96%, but not at 94% and below. Ascospores were hydrophilic, germinating best at or near 100%, RH but did not germinate at or below 93 % RH. After infection was established, tiny leafspots became visible within 6–7 days at constant temperatures of 15–25°, 10 days of 10°C, 13 days of 5 °C, and 25 days of 2.5 °C. They failed to develop into normal size spots within 4 weeks at constant temperatures near 30 °C, or near 10 °C and lower. Temporary exposure of incipiently diseased plants 1–6 days to 30–38 °C adversely affected subsequent leafspot development at 20–24°C. Inhibition depended on temperature and on the extent of post‐infection disease development.
Clostero virus‐Like Particles of Two Types Associated with Diseased Grapevines
Authors: Milne R. G. , Conti M. , Lesemann D. E. , Stellmach G. , Tanne Edna , Cohen J. 
Published: May 2008

AbstractPrevious work led to the characterization of, and the production of an antiserum to a closterovirus referred to as grapevine stem pitting‐associated virus (GSP‐AV). Using this antiserum and immunoelectron microscopy, we now show that GSP‐AV is widespread in grapevines and that a second serologically distinct closterovirus‐like particle is also widely present. One or both of the closterovirus‐like particles were often but not always associated with leafroll symptoms. However, some plants indexed as suffering from stem pitting also contained one or both of the particles.As “grapevine stem pitting‐associated virus” no longer seems appropriate as a name, we suggest changing it to grapevine virus A (GVA). We provisionally refer to the second closterovirus‐like virus as grapevine virus B (GVB).
Biological Control of Phytophthora Root Rot of Soybean by Hyphochytrium catenoides in Greenhouse Tests
Authors: Hsu S. C. , Lockwood J. L. 
Published: May 2008

AbstractMycelia of Hyphochytrium catenoides applied to soil artifically or naturally infested with Phytophthora megasperma var. sojae was effective in affording a high degree of protection of soybean plants against root rot in greenhouse tests. Seedling emergence, plant height and root diseases were restored to values near those of plants grown in soil without the pathogen, and root disease severity was greatly reduced, though never eliminated. Control was similar whether soil was treated with H. catenoides, then folded for 7 days before seeding, or if the flooding and prior incubation periods were eliminated. Abundant inoculum of H. catenoides was produced in a semi‐solid medium containing tryptone, glucose and yeast extract in which the colonies remained suspended. The inoculum, applied to vermiculite and stored in the laboratory, survived well: colony counts after 25 weeks were 63% of those present initially.
Effect of Bacterial Antagonist on Phytopthora cactorum and Apple Crown Rot
Authors: Utkhde R. S. 
Published: May 2008

AbstractBacterial antagonist B8 produced an inhibition zone with each of four Phytophthora cactorum isolates on corn meal agar (CMA) plates. Infections with three P. cactorum isolates were significantly reduced when the soil was simultaneously inoculated with B8. Growth of P. cactorum was completely inhibited on CMA amended with 40–100 per cent 10 fold concentrated B8 extract. Percent oospore germination of P. cactorum was significantly reduced when B8 was present in suspension for 9, 12 and 15 days from inoculation. Survival of oospores was significantly reduced at 60 and 90 mm depths in soil. Bacterial antagonist B8 significantly reduced the population of viable P. cactorum oospores in the top 30 mm of soil where oospores generally survive.
Occurrence of Falcarinol and Falcarindiol In Tomato Plants after Infection with Verticillium albo‐atrum and Characterization of Four Phytoalexins by Capillary Gas Chromatography‐Mass Spectrometry
Authors: Elgersma D. M. , Weijman A. C. M. , Roeymans H. J. , van Eijk G. W. 
Published: May 2008

AbstractFalcarinol and falcarindiol were isolated from tomato vascular tissue infected with Verticillium albo‐atrum and identified. Separation and characterization of trimethylsilyl derivatives of four tomato phytoalexins could be obtained by capillary gas chromatographymass spectrometry.We are most grateful to Dr. P. J. G. M. de Wit, Agricultural University, Wageningen, to Dr. D. T. Coxon, Food Research Institute, Norwich and to Dr. M. S. Kemp, Long Ashton Research Station, Bristol for making their analytical data available for us. Also thanks are due to Miss J. I. Liem, Mr. G. Verweij and C. Loriaux for their assistance.
Kugelige, umhüllte Mikrokonidien‐Aggregate als Überdauerungs‐ und Verbreitungseinheiten von Botrytis cinerea Pers.
Authors: Von Urbasch I. 
Published: May 2008

Abstract Spherical, coated microconidia‐aggregates as survival and dispersal units of Botrytis cinerea Pers. As a reaction to longer lasting unfavourable growth conditions Botrytis cinerea is able to form spherical microconidia‐aggregates enclosed in a protective coat. Genesis, structure and occurrence of these so far unknown microconidia‐aggregates are described and their function as survival and dispersal units of the fungus is discussed.
Natural Occurrence of a Strain of Cowpea Mild Mottle Virus on Groundnut (Arachis hypogaea) in India*)
Authors: Iizuka N. , Rajeshwari R. , Reddy D. V. R. , Goto T. , Muniyappa V. , Bharathan N. , Ghanekar A. M. 
Published: May 2008

AbstractVein‐clearing followed by downward rolling and necrosis of leaves and severe stunting of groundnut (Arachis hypogaea) plants were caused by cowpea mild mottle virus (CMMV). The virus was readily transmitted by mechanical sap inoculations to groundnut and to 10 plant species belonging to Leguminosae, Chenopodiaceae and Solanaceae. Chenopodium quinoa and Beta vulgaris were good diagnostic hosts. Diseased sap remained infective at 10–3 but not 10–4, when stored 8 to 9 days at 25 °C; for 10min at 75 °C but not 80°C. In limited tests, virus was not seed‐transmitted m groundnut or soybean. Virus was transmitted by Bemisia tabaci but not by Aphis craccivora or Myzus persicae. An antiserum for CMMV was produced and virus was serologically related to CMMV reported on cowpea and groundnut crinkle virus (GCV) from West Africa. Employing carbon diffraction grating replica as a standard the modal length of virus particles to be 610 nm. Infected cells contained large number of virus particles associated with endoplasmic reticulum.
Little Leaf: A Disease of Sweet Potato in Papua New Guinea Probably Caused by Mycoplasma‐Like Organisms
Authors: Pearson M. N. , Keane P. J. , Thiagalingham K. 
Published: May 2008

AbstractA disease of sweet potato which causes dwarfing and shoot proliferation is reported from the Central Province of Papua New Guinea. The disease primarily effects yield by reducing tuber number and yield reductions of more than 50 % have been recorded. Mycoplasma like organisms have been detected in the phloem cells of diseased plants using electron microscopy and may be the cause of the disease. Early stage infections can be detected using fluorescent light microscopy and this may prove an appropriate method for rapid diagnosis of the disease. Treatment of diseased plants with tetracycline results in temporary symptom remission.
Transmission Studies with Cucumber Green Mottle Mosaic Virus
Authors: Rao A. L. N. , Varma A. 
Published: May 2008

AbstractCucumber green mottle mosaic virus may spread in bottlegourd under field conditions through soil contaminated with infected plant debris followed by contact. No seed transmission was noticed in bottlegourd (Lagenaria siceraria) or vegetable marrow (Cucurbita pepo) although pollen grains and cotyledons from infected bottlegourd flowers or seeds, respectively, contained negliginle amounts of virus. Cucumber leaf beerles (Raphidopalpa fevicollis) are probable vectors since their regurgitated fluid and excretes contained infective virus particles. No vector fungi were found in the soil around infected bottlegourd plants.
Developmental Morphology of Hop Stunt Viroid‐infected Hop Plants and Analysis of Their Cone Yield1)
Authors: Momma T. , Takahashi T. 
Published: May 2008

AbstractInfection of hop plants with hop stunt viroid (HSV) results in the retardation of the growth rate except for the rate of leaf emergence and the disappearance of the fold‐like structure over the epidermal cell. Mature cones from HSV‐infected hop plants remained small‐sized and the content of α‐acid was half to one third of that of HSV–free hop cones. In HSV‐infected hop cones, the lupulin glands are distributed most abundantly on the bracteoles and the perianths and their numbers are reduced by at least 60% of that in the HSV‐free control. Scanning electron micrographs confirm that most of the lupulin glands on bracteoles from HSV‐infected hop cones shrivel severely, but not those from HSV‐free hop cones. They also reveal that the lupulin glands on the perianths from both, HSV‐free and HSV–infected hop cones become withered. Moreover, spherical granules (1.2 to 1.9μm in diameter) were not observed on the surface of the lupulin glands from HSV‐infected hop cones.
Combined Gene Effects on Resistance against Erysiphe graminis DC. f. sp. hordei Marchal Analysed by Means of Double Mutants1)
Authors: Heun M. , Röbbelen G. 
Published: May 2008

AbstractThe effect of genes for resistance against powdery mildew of barley was determined microscopically in stained leaf segments 44 h after inoculation and compared with the visual was established between the number of haustoria and the visual disease symptoms. Deviations were expressed after C17 Am inoculation of the mutant B682, which exhibited low infection grade although high numbers of haustoria were formed; thus the induced resistance gene of B682 is expressed only in later stages of the infection process. On the other hand, after inoculation of SR1 with the ml‐o virulent isolate HL3 high infection grade was measured following low haustoria numbers; obivously, this isolate is able to grow more intensively after first haustoria have been formed.Consequently, the close relation between haustoria numbers and infection grade is reestablished in the double mutants under HL3 infection. The implications of this finding for resistance breeding are discussed.
Resistance of Three Bean Cultivars to Uromyces phaseoli Expressed Through Sporulation of the Fungus
Authors: Aust H. J. , Bergamin Filho A. , Menten J. O. M. 
Published: May 2008

AbstractSporulation of the rust fungus Uromyees phaseoli was checked on three different Brasilian bean cultivars on the upper and lower leaf surface of primary leaves in a growth chamber at 21°C. Although the sporulating area of the pustules was greater on the upper leaf surface, the pustules on the lower leaf surface produced nearly two times more spores on all three cultivars.The total number of spores produced per pustule was 41,600/81,000 spores (upper/ lower leaf surface) for the susceptible cultivar Rosinha G‐2/C‐21 and for the cultivars which possess horizontal resistance: Carioca/C‐224 29,600/49,500 spores (upper/lower leaf surface), Roxo/C‐743 32,964/50,700 spores (upper/lower leaf surface). The two cultivars with horizontal resistance produced nearly a third less spores than the susceptible cultivar.
Untersuchungen zur Bildung extrazellulärer Hemicellulasen durch Pseudocercosporella herpotrichoides in vitro
Authors: Redlhammer S. , Menke G. , Grossmann F. 
Published: May 2008

Abstract Investigations on the production of extracellular hemicellulases by Pseudocercosporella herpotrichoides in vitro For all 15 isolates of Pseudocercosporella herpotrichoides investigated, xylanase as well as arabanase activity could be demonstrated. After cultivation of 3 weeks, the activity of the enzymes reached a peak. The activity of xylanase was considerably increased by addition of xylan in comparison to Maltzin as the sole source of carbohydrate. Also the arabanase activity could be increased significantly by addition of araban or xylan as compared to the Maltzin variant.The optimum temperature with regard to activity and stability of xylanase ranged at 50°C. The pH‐optimum for xylanase activity was found to be at pH 5.0, and the enzyme was stable in ° range between pH4.0 and 8.0 (9.0). In case of arabanase, the temperature optimum varied between 40 and 50°C; up to this temperature, the enzyme was also stable. At pH 5.0, the arabanase activity reached its optimum; stability was observed in ‐ pH range between 4.0 and 9.0.In extracts prepared from autoclaved wheat coleoptiles which were inoculated with Pseudocercosporella herpotrichoides, the presence of the enzymes xylanase, arabanase, cellulase and polymethylgalacturonase could be demonstrated. The enzyme activities of the inoculated samples were considerably higher than those of non‐inoculated controls. The differences, in most cases, were statistically significant.Der Deutschen Forchungsgemeinschaft danken wir für finanzielle Unterstützung.
Changes in Phenolic Acids in Groundnut Leaves Infected with Rust
Authors: Reddy M. N. 
Published: May 2008

AbstractQuantitative changes of individual phenolic acids in rust‐infected groundnut leaves were studied at various stages of disease development. There was no qualitative change in the phenolic acids. However, the concentration of the phenolic compounds increased due to infection more particularly of chlorogenic and trans and cis caffeic acids.