bluuebunny/crossref_metadata_2025_split huggingface dataset:
Independent Inheritance of Genes Governing Virulence and the Production of a Polypeptide in Ustilago hordei*
Authors: Thomas P. L. , Kim W. K. , Howes N. K. 
Published: May 2008

AbstractDetergent soluble polypeptides from teliospores of Ustilago hordei were examined by two‐dimensional isoelectric focusing‐polyacrylamide gel electrophoresis. A relatively prominent polypeptide (M.W. 28,000, P1 6.8) was found in extracts of teliospores from two isolates that were avirulent on the barley cultivar ‘Plush’ but was not detected in extracts from two isolates that were virulent on this cultivar. The polypeptide was also detected in extracts from teliospores of an F1, hybrid between one of the virulent and one of the avirulent isolates. Haploid cultures from five meiotic tetrads, isolated from the F1 hybrid, were backcrossed to haploids from the virulent parent to determine the pathogenicity of each strain. The polypeptide segregated among the 20 progeny as if under the control of a single, dominant allele. The gene governing virulence on ‘Plush’ was not linked to the gene governing the segregating polypeptide.
Increase of Fusarium Rot in Stored Citrus Fruit
Authors: Schiffmann‐Nadel Mina , Chalutz E. , Waks J. , Lomaniec Ella , Yoffe A. Z. 
Published: May 2008

AbstractIn recent years the incidence of Fusarium spp. isolated from Stem End Rot (SER) and Internal Core Rot (ICR) of grapefruit and oranges has increased markedly. Fusarium spp. were isolated from apparently healthy green buttons and from the tissue underneath the button of healthy fruits.Of all the SER‐ and ICR‐rotted fruit, the incidence of Fusarium spp. alone and of Fusarium spp. with Alternaria citri was between 75 and 100%. Fusarium was also found to be the single causal agent of ICR of oranges and grapefruit.Species of Fusarium isolated from Stem End Rot and Internal Core Rot of citrus fruit were F. oxysporum, F. moniliforme and recently also F. culmorum.
Characterization of Potyvirus Isolates from West African Yams (Dioscorea spp.)
Authors: Porth A. , Lesemann D.‐E. , Vetten H. J. 
Published: May 2008

AbstractIn comparative studies on potyviruses from West African yams (Dioscorea spp.) the following isolates were used: Dioscorea greenbanding mosaic virus (DGMV) and a Nigerian yam virus (YV‐N), both isolated from Dioscorea rotundata, and a beet mosaic virus isolate from D. alata (BtMV‐Y) formerly designated Dioscorea alata ring mottle virus. Naturally infected D. alata containing very few particles of BtMV‐Y, contained primarily particles of a second potyvirus (Dioscorea alata virus, DaV) which could not be transmitted but which was included in these studies wherever possible.The normal lengths of DGMV, YV‐N, DaV, and BtMV‐Y were 754, 772, 805, and 812 nm, respectively. All viruses induced cytplasmic inclusions of the pinwheel type and laminated aggregates. In addition, the nucleoli of BtMV‐Y infected cells contained characteristic electron dense inclusions. The buoyant density of purified DGMV and BtMV‐Y in CsCl was 1.336 g/cm3 and 1.321 g/cm3, respectively. The sedimention velocities (Srel) of DGMV, YV‐N, and BtMV‐Y were 156, 158, and 162 Srespectively. In SDS‐polyacrylamide gel electrophoresis the coat protein of purified DGMV and YV‐N all migrated as a single band with an apparent molecular weight of 36 kd. Coat protein of purified DaV showed up to 5 bands with molecular weights of 36 to, 32 kd. Polypeptides of purified BtMV‐Y had an estimated molecular weight of 35 kd but those from infected plant extracts had a molecular weight of 36 kd. DGMV, YV‐N, and BtMV‐Y particles contained a single nucleic acid with an apparent molecular weightof 3.2, 3.2, and 3.1 Md, respectively. Using λ‐DNA digested with Hind III as a marker, the molecular weight of DGMV and BtMV‐Y nucleic acid was calculated to be 3.6 Md ± 10%. The nucleic acid was determined to be single‐stranded RNA by enzymatic digestion and by staining with acridine orange.In serological studies using immunoelectron microscopy (IEM), electro‐blot immunoassay (EBIA), and enzyme‐linked immunosorbent assay (ELISA), DGMV and YV‐N were closely related. Strong serological reactions were also obtained in IEM and EBIA when DGMV and YV‐N were tested with antiserum to yam mosaic virus (YMV). Antisera against DGMV, YV‐N, and YMV also reacted strongly with DaV antigen. Serological reactions between these viruses and BtMV‐Y were usually not found or were weak. A very close serological relationship could be detected between BtMV‐Y and beet mosaic virus isolated from beet (BtMV); both isolates were also very similar in host range, symptomatology, and cytopathology.
A Field and Storage Rot of Onion (Allium cepa L. var. cepa) Caused by Pseudomonas cepacia in Lowland Papua New Guinea
Authors: Tomlinson D. L. 
Published: May 2008

AbstractA bacterium consistently isolated from rotting onions in the field and in storage was shown by biochemical and pathogenicity tests to be Pseudomonas cepacia. In experiments to determine the mode of entry of the pathogen only injured bulbs developed a soft rot after a 10 min soak in a suspension of P. cepacia (approx. 108 cfu/ml).
Effects of Two Carboxylic Acid Anilide Fungicides on Pustule Development and Carbohydrate Movement and Metabolism in Barley Leaves Infected by Brown Rust (Puccinia hordei Otth.)
Authors: Whipps J. M. , Roderick H. W. , Clifford B. C. , Lewis D. H. 
Published: May 2008

AbstractThe effects of two concentrations of two carboxylic acid anilide fungicides (benodanil and oxycarboxin) on fungal growth, carbohydrate movement and metabolism in barley leaves infected with Puccinia hordei were investigated using radiological, biochemical and histological techniques. At the higher concentration, both fungicides killed the fungus and prevented normal movement of carbohydrate to the pustules and accumulation of fungal carbohydrates. Autoradiography showed that small amounts ofassimilates accumulated at infection sites when leaves or leaf segments were treated with the lower concentration that allowed slight fungal growth. Associated biochemical changes were monitored. Possible mechanisms involved in the alterations caused bythe fungicides are discussed.
Occurrence of Malformin‐like Substances in Seedlings of Mango (Mangifera indica L.)*
Authors: Singh Zora , Dhillon B. S. 
Published: May 2008

AbstractThe ether soluble extracts from stem and root tissues of malformed seedlings of mango showed four malformin‐like substances on chromatograms in the corn root curvature test at Rf 0–0.1 (M1), 0.1–0.2 (M2), 0.8–0.9 (M9) and 0.9–1.0 (M10). M10 was identified as a malformin A‐like substance(s). Stems and roots of malformed seedlings contained high levels of malformin A‐like substance(s) (42.0 μg/g and 41.0 μg/g) respectively, which were absent in stems and roots of healthy seedlings.
The Role of White Mold‐Infected White Bean (Phaseolus vulgaris L.) Seeds in the Dissemination of Sclerotinia sclerotiorum (Lib.) de Bary
Authors: Tu J. C. 
Published: May 2008

Abstract Sclerotinia sclerotiorum survived in infected seeds of white beans as dormant mycelium in testa and cotyledons. The rate of survival averaged 85 to 89% and did not change appreciably over a 3‐year period. When the infected bean seeds were sown in soil or sand, 88 to 100% failed to germinate. The seeds that failed to germinate, depending on the severity of seed infection, were rotted by S. sclerotiorum. In place of each seed, 3 to 6 sclerotia were formed. A low percentage of these sclerotia germinated carpogenically with or without preconditioning, (2.5 and 11.5% respectively). Myceliogenic germination of sclerotia with and without preconditioning was 35.5% and 70.5% on water agar and 81.0% and 93.0% on glucose agar, respectively. Both, preconditioning and nonpreconditioned sclerotia which were scattered on soil surface could germinate myceliogenically and infect bean leaves by contact. It is therefore, concluded that dormant mycelia in the infected seeds play an important role notonly in dissemination of the fungus but also in epidemiology of the disease.
Seed Transmission of Telfairia Mosaic Virus in Fluted Pumpkin (Telfairia occidentalis Hook f.) in Nigeria
Authors: Anno‐Nyako F. O. 
Published: May 2008

AbstractTelfairia mosaic virus (TeMV) was transmitted through seeds of four highly susceptible cultivars of fluted pumpkin (Telfairia occidentalis Hook f.) in a screenhouse experiment.Infection was confirmed through visual appraisal and electron microscopy in cvs NHTo 75–10 (14), 54–4 (4), 54–4 (7), and 6–7 (14), to the extent of 20, 10, 6.4 and 6 % respectively.
Rhabdovirus‐Like Particles in Crinkle‐Diseased Strawberries in Germany
Authors: Jelkmann W. , Lesemann D. E. , Casper R. 
Published: May 2008

AbstractThin sections of midribs from a Fragaria vesca UC‐5 indicator plant infected by leaf grafting with a German isolate of strawberry crinkle contained typical rhabdovirus‐like particles within cytoplasmic vesicles. Masses of rhabdovirus‐like particles with a dark stained core and a transparent surrounding layer were seen in necrotic cells surrounding the vascular bundle and in necrotic leaf parenchyma.
Multiplication of Pseudomonas solanacearum in Rhizosphere and Root Tissue of Susceptible and Resistant Varieties of Solanum melongena
Authors: Khan A. N. A. , Shetty K. S. , Patil R. B. 
Published: May 2008

AbstractThe population build‐up of Pseudomonas solanacearum in the rhizosphere, and root‐tissues of two egg plant varieties, susceptible and resistant, raised in infested soil was investigated at different stages of plant growth. There was no perceptible difference in the population build‐up of the pathogen in the non‐rhizosphere soils of both the susceptible and resistant plants. However, the soil 3 cm away from the tap root of the susceptible variety contained a higher population of the pathogen compared to the soil similarly drawn from the resistant plants. The pathogen population in the rhizosphere of the susceptible variety increased 1,000‐fold with increasing age of the plant and was highest at flowering. The rhizosphere of the resistant plant, showed only a 10‐fold increase in pathogen population. The trend was similar with the root tissue populations of the pathogen, but the differences in the root tissue populations of the resistant and susceptible plants were more pronounced. Considerable, buildup of the pathogen population in the susceptible variety was also seen in the above ground portions of the plants. Root extracts of the resistant variety had a marked inhibitory effect on the growth of the pathogen.
Occurrence of Southern Bean Mosaic Virus on Cowpea in Senegal
Authors: Gaikwad D. G. , Thottappilly G. 
Published: May 2008

AbstractFor identification of cowpea viruses existing in Senegal, 180 samples collected from 4 different locations were examined. Initially agar gel diffusion tests were employed to identify the viruses present in these samples using antisera to 3 beetle‐transmitted viruses viz. CPMV, SBMV and CMeV. The results indicated the presence of SBMV in 78 samples mostly from Casamance while none of these viruses were detected in the samples collected from northern Senegal. These results were later confirmed by Enzyme‐linked Immunosorbent Assay (ELISA). This is the first report of occurrence of SBMV in Senegal.
A Muslin Wick Culture Technique for Mass Production of Conidia of Venturia inaequalis
Authors: Puttoo B. L. , Basu Chaudhary K. C. 
Published: May 2008

AbstractFor in vitro and glasshouse studies, mass production of conidia of Venturia inaequalis is essential. A wick culture technique utilising ordinary muslin cloth in 250 ml prescription bottles wetted in 4 % malt extract medium and maintained at 18 ± 2°C for 21 days in darkness produced abundant conidia and proved superior to other methods.
Variations of Phenoloxidase Activities as a Consequence of Stresses that Induce Resistance to Fusarium Wilt of Tomato
Authors: Abbattista Gentile I. , Ferraris L. , Matta A. 
Published: May 2008

AbstractThe variations over 7–8 day of peroxidase (PO) and polyphenoloxidase (PPO) activity have been investigated in tomato plants the roots of which had been subjected to stresses (heat, chloroform and a non‐pathogenic form of Fusarium oxysporum) that induce resistance to Fusarium oxysporum f. sp. lycopersici.All treatments induced increase of PO and PPO activity that reached a maximum 3 days after the treatments in leaves, 4 days in stem and roots and were higher in leaves than in other parts. Activity decreased to levels for the control plants after 8 days.Inoculation with Fusarium oxysporum f. sp. lycopersici further stimulated PO and PPO activity in all treated plants over that caused by the treatments alone. Again, activity of treated plants was lower than in controls 7 days after inoculation.It is concluded that 1. increased PO and PPO activity in tomato is a systemic response to cellular injury caused in the root by heat, chloroform and non‐pathogenic Fusarium oxysporum, 2. these treatments do no prevent the pathogen from interacting with the plants and inducing further enzyme increase, 3. treated plants react more strongly to the challenge inoculation than untreated plants.
Relationship of Cyanogenic Capacity (HCN‐c) of the Rubber Tree Hevea brasiliensis to Susceptibility to Microcyclus ulei, the Agent Causing South American Leaf Blight
Authors: Lieberei Reinhard 
Published: May 2008

AbstractLiberation of HCN from cyanogenic plant tissue depends on cyanogen content (HCN‐potential), cyanogen splitting enzymes, cyanohydrin cleaving activity (hydroxynitrile lyase) and nonenzymatic cyanide detoxifying compounds. The maximal amount of HCN potentially set free is governed by the total cyanogen content, whereas the velocity of HCN liberation depends on enzymatic activities (β‐glucosidase [β‐G], hydroxynitrile lyase [HN]). Plants revealing a high HCN‐potential and a high β‐glucosidase activity generally are susceptible to infection with Microcyclus ulei. Based on the data of HCN‐p and β‐G activity of different Hevea species a proposal for future screening work in Hevea resistance selection is given.
Behaviour of Phytophthora citrophthora and P. nicotianae var. in soil, and Differences in Their Tolerance to Antimicrobial Components of Selective Media Used for Isolation of Phytophthora spp.
Authors: Sneh Baruch , Katz DaniellaA. 
Published: May 2008

Abstract Phytophthora citrophthora was inhibited to a greater extent than P. nicotianac var. parasitica by chloramphenicol, hymexazol, PCNB and pimaricin at concentrations used in selective media for the isolation of Phytophthora spp. Reduced concentrations of the antimicrobial components of the selective media to tolerant levels for P. citrophthora markedly increased the recovery of the two brown rot pathogens from soil.Mycelium of both Phytophthora spp. survived in air‐dried soil for at least 5 months while mycelium of most Phytophthora spp. do not survive in dry soil. In moist soil, P. nicotianae var. parasitica produced hyphal swellings, sporangia and chlamydospores. P. citrophthora produced hyphal swellings and sporangia, but no chlamydospores. No oospores were produced, even in pairing cultures on agar plates with isolates obtained from several locations of citrus groves andfruits by both species. Sporania were obtained in both species in citrus groves on mycelium mats, in the rhizosphere, in infected leaves and fruits buried at soil depths of 5–35 cm. Numbers of propagules declined during the incubation period, but conside, rable numbers survived throughout the experimental period (6 months). Although P. nicotianae var. parasitica produced chlamydospores while P. citrophthora did not, numbers of surviving propagules recovered from soil after 6 months were comparable with both species. The brown rot pathogens survived in soil both as colonizers of detached leaves and fruits and as parasites in living root tissues.
Development of Infection Structures by the Direct‐Penetrating Soybean Rust Fungus (Phakopsora pachyrhizi Syd.) on Artificial Membranes
Authors: Koch E. , Hoppe H. H. 
Published: May 2008

AbstractThe development of infection structures by the directly infecting soybean rust fungus of different artificial membranes was followed by light and scanning electron microscopy. On water agar uredospores developed germ tubes without appressoria. On dialysis membranes more than 80% of the uredospores formed appressoria. With low frequencies (1–7%) also primary hyphae and/or penetration hyphae were present. When cellulose nitrate membrane filters with pore diameters ≤ 0.2 μm were used, uredospores germinated but showed a strongly reduced appressoria formation. Membranes with pores ≥ 0.1 μm allowed a development of infection structures similar to that on dialysis membranes. In experiments with paraffin oil incorporated into collodion membranes more than 90% of the uredospores formed appressoria, about 50% of the appressoria developed hyphae. Ungerminated spores and germ tubes always contained 2 nuclei. In fully developed appressoria 4 nuclei were present. Compared with stomata entering rust fungi appressoria formation by Phakopsora pachyrhizi occurred more frequently and seemed to be less dependent on specific stimuli. Moreover, in most cases only few of the appressoria formed penetration or primary hyphae. The induction of these structures seemed to be dependent on further unknown stimuli.
Prevention of Bacterial Wilt of Grasses by Phylloplane Bacteria
Authors: Schmidt Dorothea 
Published: May 2008

AbstractVarious chromogenic bacteria were isolated from the mowing site in natural and sown meadows and in pastures. Their ability to protect young ryegrass plants from wilt by simultaneous inoculation with Xanthomonas campestris pv. graminis was tested under low concentrations of the parasite inoculum. From about 200 isolates tested 35% had a very high protective effect, 45% a moderate one, and only 20% had no significant effect. Mixtures of different species of phylloplane bacteria usually gave very good protection. Most of these bacteria live between the leaf‐sheaths. In vitro antagonism of the phylloplane bacteria was not related to their protective effect. Avirulent mutant strains of X. c. pv. graminis and pathovars, of other grass species, e.g. pv. poae, pv. phlei, and pv. arrhenatheri, have the same protecting effect. Heat killed bacteria were no longer effective.These observations suggest an unspecific reaction of the plant, such as the induction of a general defense mechanism which results in resistance also to the parasite.
Detection of Pseudocercosporella herpotrichoides (Fron) Deighton in Wheat by Indirect ELISA
Authors: Unger J.‐G. , Wolf G. 
Published: May 2008

AbstractAn indirect ELISA for quantitative detection of P. herpotrichoides in fections in wheat is presented. All tested isolates of the virulent varieties P. herpotrichoides var. herpotrichoides, P. h. var. acuformis or the W‐ and R‐type react on a high level in the test, while the less virulent P. anguioides is assessed only with 40% and the avirulent P. aestiva with 20% of the homologous reaction. No crossreactions occur with extracts of 11 other species of in, vitro cultivated fungi nor with plant material infected with other pathogens. The infection profile throughout the leaf‐sheaths was clearly reflected by ELISA. The examination of 24 stembase samples from the field showed that the values assessed by ELISA correlate well also with the disease indices of naturally infected plant material.
Changes in the Lipid Composition of Rhizoctonia solani Infected Groundnut Hypocotyls
Authors: Reddy M. N. , Sujathamma P. 
Published: May 2008

AbstractAlterations in the total and individual lipids in healthy and Rhizoctonia solani infected groundnut hypocotyl tissues were determined. Infection resulted in an increase in the total as well as individual lipid components at various stages of disease development.
Races of Xanthomonas campestris pv. malvacearum (Smith) Dye, the Causal Organism of Bacterial Blight of Cotton, in Nigeria
Authors: Poswal M. A. T. 
Published: May 2008

AbstractRaces 6, 7 and 10 of Xanthomonas campestris pv. malvacearum (Smith) Dye, the causal organism of bacterial blight of cotton, were identified among twelve isolates of the pathogen from the three cotton growing zones of Nigeria. Races 7 and 10 were, however, predominant. The races were distinguished by inoculation of eight cotton lines known to differentiate through possession of different resistance genes. Further work is necessary, on a much greater number of isolates, to determine therange and distribution of different virulence types in Nigeria.
PhytophthoraRoot Rot of Pepper Influence of Host Genotype and Pathogen Strain on the Inoculum Density‐Disease Severity Relationships
Authors: Palloix A. , Daubeze A. M. , Pochard E. 
Published: May 2008

AbstractThe relationship between inoculum density and mortality or infection was studied for various pepper varieties (Capsicum annuumL.) inoculated with zoospores of twoP. capsiciisolates. The inoculum concentrations required for 50% mortality (LD 50) varied greatly between pepper varieties andP. capsiciisolates: with one isolate, LD 50 was 40 zoospores/ml for a susceptible variety and reached 4,380 to 97,300 zoospores/ml for resistant varieties. For another isolate, LD 50 for the, same varieties ranged from 26 to 800 zoospores/ml. Comparisons between LD 50 and inoculum doses required for 50 % Infection (ID 50) also revealed differences between varieties but not between isolates. After multiple infection correction, regression slopes of infections/inoculum concentration were low for resistant varieties (0.28 to 0.50) but higher for susceptible varieties (0.72 to 0.94), indicating strong competition between spores for infection of resistant plants, but not for infection of susceptible plants. This analysis provided many criteria which can be used to differentiate susceptible from resistant varieties and to evaluate with precision the resistance level of the different resistance genitors used in our breeding program.
Physical Factors that Influence the Growth and Spread of Charcoal Rot Pathogen (Macrophomina phaseolina) Infecting Maize
Authors: Kaiser S. A. K. M. , Das S. N. 
Published: May 2008

AbstractThe rabi maize, that is being popularised in the eastern parts of the country may suffer from charcoal rot disease [Rhizoctonia bataticola Taub. Butl. (Macrophomina phaseolina (Tassi) Goid.)] if the pathogen gets timely entry into the host, as has been revealed in the present study. In vitro studies show that the spread of the pathogen within the maize stalk is influenced by high temperature, the optimum being 38°C. The role of RH on the incidence of this disease was, however, not well defined. These observations hold true as well for the data recorded in the field.
Isolation and Characterization in Gynura aurantiaca of a Possible Citrus Rhabdovirus
Authors: Rodriguez J. L. , Diaz‐Ruiz J. R. , Flores R. 
Published: May 2008

AbstractRhabdovirus particles were detected in greenhouse‐grown Gynura aurantiaca plants during a study of citrus diseases, and some of their biological and physicochemical properties were determined. The gynura plants displayed vein clearing of young leaves as the earliest symptom and later on, an anomalous growth of some leaves. This syndrome could be easily transmitted by graft, dodder and, with more difficulty, by sap inoculation. Electron microscopy showed bacilliform virions of about 260 × 70nm, in perinuclear spaces. Purified rhabdovirus particles inoculated to healthy plants were infectious, showing that this virus was the causal agent of the gynura syndrome. An estimate of the buoyant density in sucrose of the virus gave a value of 1.17g/,cm3. Analysis of virion proteins by SDS‐PAGE revealed four major bands of relative molecular mass 81.5, 56.6, 31.6 and 24.6 x 103, suggesting that these corresponds to the G, N, M1 and M2 proteins respectively, of the subgroup B of plant rhabdoviruses. From these data we conclude that the rhabdovirus here described should be placed in the potato yellow dwarf virus subgroup of plant rhabdoviruses. The fact that a Citrus could be the original source of the virus is discussed.