bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of Polyphenol Oxidase and Peroxidase in Potato Tuber Resistance to Soft Rot Caused by Erwinia carotovora
Authors: ŁOjkowska E. , Hołubowska M. 
Published: May 2008

AbstractTubers from somatic hybrids produced by protoplast fusion between Solanum brevidens, a diploid, non‐tuber‐bearing wild species, and a tetraploid S. tuberosum showed resistance to decay caused by soft rot Erwinia. Tubers of the S. tuberosum fusion parent and potato cultivar Russet Burbank are susceptible to bacterial soft rot. Tubers of somatic hybrids indicated higher levels of activities of polyphenol oxidase and peroxidase than tubers of the parental line of S. tuberosum and cultivar Russet Burbank. This is true for intact tubers and also for injured or inoculated tubers.Polish commercial potato cultivars indicated a higher susceptibility to soft rot than somatic hybrids. However, there were some differences in susceptibility to soft rot between Polish commercial potato cultivars, only slight differences were observed in the activities of the polyphenol oxidase and peroxidase between Polish cultivars. A relation between soft rot resistance and the activity of each enzyme was not found for intact, injured or inoculated tissue of commercial cultivars. On the contrary, the activities of both enzymes were significantly higher in the periderm than in the medullary tissue of somatic hybrids, the parental line and the commercial cultivars.
Isolation and Pathogenicity of Rhizosphere Fungi of Cocoyam in Relation to Cocoyam Root Rot Disease
Authors: Pacumbaba R. P. , Wutoh J. G. , Eyango Sama Anne , Tambong J. T. , Nyochembeng L. M. 
Published: May 2008

AbstractCocoyam is the second most important staple crop of Cameroon and root rot is a destructive disease of this plant. Pythium myriotylum (Pm), Fusarium solani (Fs), and Rhizoctonia solani (Rs) were isolated from the rhizosphere of root rot affected cocoyams and from the soil of a cocoyam experimental field plot temporarily devoid of same in Mamu, Cameroon. Pm was isolated from the above soil by the cocoyam leaf disc baits. Fs and Rs were also isolated from the same soils by the water dilution method and from the roots of diseased cocoyams but were always associated with mycelial growth of Pm. Pathogenicity of Pm and in combinations with Fs or Rs or Fs + Rs all developed cocoyam root rot disease (CRRD) symptoms on 3– and 7–month old cocoyam plantlets 2–7 days after inoculation. Symptoms included rotted roots and wilting with general chlorosis of inoculated plantlets. No symptoms of CRRD were noted on cocoyam plantlets inoculated with Fs, Rs, Fs + Rs, and distilled water. Results indicated that CRRD is not caused by several pathogens but only by Pm. Pm isolates from the soils and roots of diseased cocoyams and those maintained in the ROTREP laboratory have significantly bigger diameter of mycelial colony growth in 24 h–period at 31 °C on lima bean sucrose agar, V–8 juice sucrose agar, and potato sucrose agar than on potato dextrose agar and 2 % water agar. The cocoyam plantlets were raised axenically from tissue culture of explants in the laboratory.
The Effect of Glomus mosseae and Enterobacter aerogenes on Apple Seedlings Grown in Apple Replant Disease Soil
Authors: Utkhede R. S. , Li T. S. C. , Smith E. M. 
Published: May 2008

AbstractInoculation of apple seedlings with the mycorrhizal fungus Glomus mosseae significantly increased their growth in apple replant disease soil that was neither pasteurized nor fertilized with monoammonium phosphate. The application of Enterobacter aerogenes and peat suppressed the stunting effect observed in apple replant disease soil. These results suggest the potential of using G. mosseae alone or a E.aerogenes and peat combination for the control of apple replant disease.
Purification and Characterization of Indian Cassava Mosaic Virus
Authors: Mathew A. V. , Muniyappa V. 
Published: May 2008

AbstractThe Indian cassava mosaic virus (ICMV) was transmitted by the whitefly Bemisia tabaci and sap inoculation. ICMV was purified from cassava and from systemically infected Nicotiana benthamiana leaves. Geminate particles of 16–18 × 30 nm in size were observed by electron microscopy. The particles contained a single major protein of an estimated molecular weight of 34,000. Specific antiserum trapped geminate particles from the extracts of infected cassava and N. benthamiana plants in ISEM test. The virus was detected in crude extracts of infected cassava, ceara rubber, TV. benthamiana and N. tabacum cv. Jayasri plants by ELISA. ICMV appeared serologically related to the gemini viruses of Acalypha yellow mosaic, bhendi yellow vein mosaic, Croton yellow vein mosaic, Dolichos yellow mosaic, horsegram yellow mosaic, Malvastrum yellow vein mosaic and tobacco leaf curl.
Leaf Spot of Hemp Dogbane Caused by Stagonospora apocyni, and its Phytotoxins
Authors: Venkatasubbaiah P. , Baudoin A. B. A. M. , Chilton W. S. 
Published: May 2008

Abstract Stagonospora apocyni causes a leaf spot disease on hemp dogbane (Apocynum cannabinum L.). The fungus produced phytotoxins citrinin, mellein, tyrosol and α–acetylorcinol in liquid culture. All toxins caused necrosis when placed on leaves of hemp dogbane, and eight other weed species. All four toxins were non–specific phytotoxins. Citrinin showed antimicrobial properties against some bacteria and fungi.
Blossom–end Rot of Pears: Systemic Infection of Flowers and Immature Fruit by Botrytis cinerea1
Authors: de Kock Selma L. , Holz G. 
Published: May 2008

AbstractA histological study was made of the systemic growth of Botrytis cinerea from styles, stamens and sepals to the flower receptacle and mesocarp of immature pear fruit. In most styles, hyphal growth ceased in the upper portion at the onset of stylar senescence, which occurred at about 1 wk after full bloom. Hyphae never passed through styles into the carpel. Unlike the styles, hyphae in filaments grew without restriction and progressed within 4 days, via vascular tissue, through sepals into tissues of the upper end of the flower receptacle, or of the mesocarp adjoining the sepals, without causing symptoms. Filaments remained green to partly green until harvest. B. cinerea entered filaments and spread into the receptacle or mesocarp at any time between blossoming and harvest and then became latent in these tissues. Filaments were, however, more susceptible at the flowering stage. After 2 months floral tubes were closed, and the stamens protected from infection. Careful inspection of ripe, cold–stored fruit showed that decay invariably spreads from mesocarp tissue adjoining the sepals, outward along the vascular bundles, but not from secondary inoculum in the floral tube. The behaviour of the pathogen suggests that control of blossom–end rot could be achieved if pears are sprayed with fungicide at 75—100% petal fall (when most stamens are exposed) and a month later (before floral tubes started to close).
Interactions Between Race 2 of Fusarium oxysporum f. sp. Lycopersici and Near‐Isogenic Resistant and Susceptible Lines of Intact Plants or Callus of Tomato 58731 F71 137
Authors: Kroon B. A. M. , Elgersma D. M. 
Published: May 2008

AbstractThe interaction between Fusarium oxysporum f. sp. lycopersici race 2 and near‐isogenic resistant and susceptible tomato lines of the cultivar Moneymaker and callus cultures derived from these lines was studied. Resistance was expressed in callus tissue for a short period, during 4 days after inoculation. This was shown by a delay in fungal growth on callus tissue derived from resistant plants. Accumulation of the phytoalexin rishitin was similar in callus tissue and whole plants. Tomato plants resistant to race 2 did not accumulate more rishitin than susceptible plants during the first 4 days after inoculation, in contrast to plants resistant to race 1 and inoculated with race 1. The different response of tomato plants and calli towards race 1 and 2 of F. oxysporum f. sp. lycopersici suggests that the mechanism of resistance controlled by the 1–1 and the 1–2 gene is different. Callus tissue might be useful to study these differences in resistance.
About Changes in the Chromatin Structure after Resistance Induction in Hordeum vulgare L.
Authors: Kraska T. , Schönbeck F. 
Published: May 2008

AbstractThe application of the three resistance inducers Trigonelline (N‐Methyl‐nicotinic acid), Isonicotinic acid methyl ester and the culture filtrate of Bacillus subtilis (B 50) to barley resulted in a reduction of infection with powdery mildew up to 65 %. When the isolated high molecular‐weight DNA was hydrolized to single bases the genomic DNA methylation of induced resistant plants was reduced between 3.1 % and 4.8 % compared to the control. On the basis of the given results the hypothesis that inducers could change the DNA structure is discussed considering further information from literature about gene regulation.
Studies of Polyclonal Antibodies for the Detection of MLOs Associated with Faba Bean (Vicia faba L.) Using Different ELISA Methods and Dot‐blot
Authors: Saeed Essam M. , Roux Jacqueline , Cousin Marie‐Thérèse 
Published: May 2008

AbstractPolyclonal antibodies were raised in rabbits against MLO associated with faba bean (Vicia. faba L.) phyllody which exists in the Sudan. Two indirect ELISA methods were able to detect the MLO antigens. In the former, the whole antigen was directly coated onto plates, while in the second, only the F(ab')2, fragments of the IgG were used to coat the ELISA plates. Higher detectable efficiency was obtained when the F(ab')2 method was used. Moreover the obtainable antiserum was found to exhibit a high degree of specificity through which the MLO associated with faba bean phyllody in the Sudan, are serologically differentiated from other isolates of MLO existing in the Sudan as well as European MLO isolates maintained at Versailles, and Spiroplasma citri, causal agent of Citrus Stubborn Disease. The positive reactions obtained with this antiserum against MLO phyllody naturally existing in the Sudan on Crotalaria saltiana and some Catharanthus roseus demonstrate that these plants are potential reservoirs of the disease in the Sudan. The same antiserum was used in order to distinguish healthy and diseased plant preparations using the membrane ELISA method (dot‐blot).
Occurrence of Mosaic Mottle, a Viroid Disease of Pigeonpea (Cajanus cajan) in India
Authors: Bhattiprolu S. L. 
Published: May 2008

AbstractDuring investigations of viroid diseases of food crops in Delhi, India, an infectious low‐molecular‐weight RNA (Mr 1.3 × 105) was isolated from pigeonpea (Cajanus cajan) plants showing mosaic mottling and reduced size of leaves, stunting and no flowering. This RNA infected mechanically inoculated C. cajan, Chenopodium amaranticolor, Nicotiana glutinosa, and N. clevelandii. The causal agent, for which the name pigeonpea mosaic mottle viroid (PMMVd) is proposed, differed from N. glutinosa stunt viroid (NgSVd), the only viroid reported to infect legumes, in size and symptom expression on the original host species.
Cytopathology of Lettuce Mosaic Virus‐infected Lettuce Seeds and Seedlings
Authors: Hunter D. G. , Bowyer J. W. 
Published: May 2008

AbstractThe ultrastructure of lettuce mosaic potyvirus (LMV)‐infected lettuce seeds and seedlings was studied by transmission electron microscopy. Conventional thin‐section electron microscopy and immunogold cytochemistry were both successfully employed to study the location of LMV in embryonic and non‐embryonic seed parts. LMV particle aggregates and cytoplasmic “pinwheel” inclusions characteristic of potyviruses were observed throughout the embryonic tissues (radicle, hypocotyl and cotyledon) of infected lettuce seeds and seedlings, and also in the non‐embryonic endosperm layer. LMV particles, but not inclusions, were also located in the non‐embryonic pericarp layer.
Cucumber Vein Yellowing Virus; Host Range and Virus Vector Relationships
Authors: Mansour A. , Al‐Musa A. 
Published: May 2008

AbstractCucumber vein yellowing virus (CVYV) is transmitted by Bemisia tabaci, it has a narrow host range restricted to some cucurbitaceous plants including Cucumis sativus, C. melo, C. melo var. flexousus, Cucurbita pepo, C. foesti, Citrullus vulgaris, C. colocynthis and Lagenaria siceraria.Although a single whitefly can transmit the disease, the efficiency of transmission was low. At least 15–20 insects per plant were required to cause an infection of 55 % of inoculated plants. The minimum acquisition and inoculation feeding periods were 30 and 15 min, respectively.The latent period in the vector is about 75 min and the whitefly was infectious for not more than 5 h.
Serological Specificity of the Lipopolysaccharides, the Major Antigens of Pseudomonas syringae
Authors: Guillorit Christians , Samson Regine 
Published: May 2008

AbstractThe nature of major antigens of Pseudomonas syringae was studied on one strain of four pathovars (pvs aptata, mors‐prunorum, phaseolicola and tabaci) belonging to four separate serogroups. Bacterial antigens were prepared by 4 procedures: extraction by phenol‐water (PW), by citrate‐NaCl (CN), by trichloracetic acid (TCA), and precipitation of a glycoproteic extracellular complex (GP). 3‐Deoxy‐2‐octulosonic acid (KDO) revelation in all the extracts showed that the four procedures led to antigens containing similar amounts of lipopolysaccharide (LPS). Twenty polyclonal antisera were raised in rabbits against whole bacteria and the different extracts. Serological reactions were tested by gel double diffusion (DD) and indirect immunofluorescent staining (IF).The anti‐whole cell sera were shown to contain mostly anti‐LPS antibodies. For each pathovar, whole bacteria used as antigens in DD gave precipitation bands identical to the bands given by the LPS extracts (PW, CN or TCA), identical to the heated bacteria (HB), and identical to LPS sidechain preparations. The GP extract itself was shown to be rich in LPS. To serotype P. syringae, it is advised to raise antisera against either whole bacteria or GP extracts; whereas the reacting antigens for DD would be heated bacteria.
Etiology of a Root Rot Disease Complex of Alstroemeria in Alberta, Canada
Authors: Chang K. F. , Mirza M. , Hwang S. F. 
Published: May 2008

Abstract Fusarium oxysporum, Pythiu‐m ultimum, and Rhizoctonia solani were isolated from the basal stems of diseased alstroemeria showing symptoms of dark brown stripes along leaf margins, leaf chlorosis, plant wilting, browning or rotting of basal stem, rhizome, and storage and fibrous roots. The pathogen isolated most frequently was Fusarium spp. (40.5 % of plants examined). Pythium spp. and R. solani were isolated less frequently (5.5 % and 6.8 % of plants examined, respectively). F. oxysporum caused the highest mortality in alstroemeria when rhizomes were grown in unsterilized soil‐less mix medium. This is the first report in North America of a root‐rot disease complex affecting alstroemeria.
Chalara elegal‐Infected Tobacco Roots: Ultrastructural Observations on in vitro Host‐Fungus Relationships
Authors: Tahiri‐Alaoui A. , Gianinazzi S. , Dumas‐Gaudot E. 
Published: May 2008

AbstractEvidence, based on ultrastructural observations of stages involved in root infection oi Nicotiana tabacum cv. Xanthi n.c. in vitro by the black root rot fungus Chalara elegans, indicates that host cells from various layers react differently when challenged by the pathogenic fungus. All the host responses observed were associated with host cell wall modifications. Host reaction to fungal invasion occurring in the epidermal cells was limited to a disorganization of the cytoplasm. In the hypodermal cell layer, fibrillar cell wall outgrowths and wall thickenings were the earliest and the most obvious host reactions. In parenchymal cells, the host reacted by depositing papilla‐like wall appositions directly adjacent to the infecting hyphae; with secondary infection of these cells, a densely staining material was laid down, mainly around the distal region of the infecting hyphae. In all these tissues, infection also led to disorganization of the host cytoplasm. Colonization of the endodermis did not lead to any rapid lethal modifications in either the host or the fungus, and a biotrophic‐like state seemed to occur at this stage of the infection. No hyphal infection occurred in the central cylinder.
Strains of Peanut Stripe Potyvirus Rapidly Identified by Profiling Peptides of the Virion Proteins
Authors: Kittipakorn Kruapan , McKern Neil M. , Gibbs Adrian J. , Shukla Dharma D. 
Published: May 2008

AbstractVirion proteins of five potyvirus isolates from groundnut in Thailand which induce a range of symptoms were compared with those from the type strains of peanut stripe potyvirus (PStV) and peanut mottle potyvirus (PeMoV). Profiles obtained by high performance liquid chromatography (HPLC) of tryptic peptide digests of the virion proteins of all five Thai isolates and PStV were very similar, whereas that of PeMoV was quite different. The results indicate that the Thai isolates are strains of PStV, and reaffirm the value of HPLC peptide profiling for rapidly identifying potyviruses.
Crassulacean Acid Metabolism in Two Species of Orchids Infected by Tobacco Mosaic Virus‐orchid Strain and/or Cymbidium Mosaic Virus
Authors: Izaguirre‐Mayoral Maria Luisa , De Uzcategui Rafaela C. , Carballo O. 
Published: May 2008

AbstractThe effect of viral infections on the Crassulacean Acid Metabohsm (CAM) was determined in two orchid species. Plants of a Sophrolaeliocattleya (SLC) commercial hybrid were inoculated with either the orchid strain of the Tabacco Mosaic Virus (TMV‐O), with Cymbidium Mosaic Virus (CybMV) or with a mixture of both viruses. Plants of Epidendrum elongatum, a wild terrestrial orchid, were inoculated either with TMV‐O or with TMV‐O and CybMV simultaneously. Virus infected plants started to show a systemic mosaic on the leaves 3 to 4 years after inoculation, the symptoms being more appreciable in SLC than in E. elongatum. Double inoculation with TMV‐O and CybMV proved to the lethal for the SLC plants. TMV‐O infection caused 58 % and 24 % reduction in nocturnal leaf titratable acidity (TA) in SLC and E. elongatum, respectively. TMV‐O also changed the daily pattern of leaf nonstructural carbohydrates typical of CAM plants. A 50 % decrease in TA at dawn and a mid‐morning peak of sugar accumulation were measured in leaves of doubly inoculated E. elongatum plants. In SLC CybMV infection inhibited CAM and induced an accumulation of glucans in the leaves. Cytoplasmic agglomerations of CybMV, but not of TMV‐O, were detected in SLC mfected cells, whereas TMV‐O particles were clearly observed in the cytoplasm of E. elongatum. Infection by TMV‐O or CybMV in SLC caused an increase in chloroplasts volume and distortion of the grana due to high glucan accumulation. In contrast, TMV‐O infection in E. elongatum induced a lesser degree of damage in the cell ultrastructure.
Germination of Teliospores of Tilletia bardayana, the Causal Agent of Kernel Smut of Rice, in Relation to Some Physical Factors
Authors: Ghahal S. S. , Aulakh K. S. , Mathur S. B. 
Published: May 2008

AbstractTeliospores of Tilletia harclayana germinated equally well on the surface of 2 % water agar, soil extract agar and in cavities made in water agar. Maximum germination occurred at 29 °C under 12 h photoperiod with artificial daylight (cool fluorescent light). There was marked increase in germination when the teliospores in bunted grains were pre‐treated for 30 min at 60 °C. Seventeen‐week‐old tehospores did not germinate while 73 week‐old‐tehospores showed retention of good germinability. Teliospores buried at 2 mm depth showed no germination whereas those at the moist surface germinated to produce sporidia. Implications of these results in the disease development are discussed.
Enantioselective Antiphytoviral Activity of l‐(α‐carboxyalkyl)‐4,5‐dimethyl imidazol‐3‐oxides in Systemically Infected Host Plants
Authors: Bauer Ute , Kluge S. , Nuhn P. , Stengerand P. , Lettau H. 
Published: May 2008

Abstractl‐(α‐carboxyalkyl)‐4,5‐dimethyl imidazol‐3‐oxides were tested as D forms, L forms and racements to their antiviral activity to red clover mottle virus (RCMV) and alfalfa mosaic virus (AMV) in systemically infected host plants. A high enantioselective activity of antiphytoviral compounds was detected.While the D forms reduce the virus content by more than 90 %, the L forms do no show any antiviral activity. With a virus‐inhibiting activity of 40 to 50 %, the racemates are in between these two forms and similar to Virazole. The optimal effective dose is 10–2 mol × 1–1 for the D forms. Reduced virus concentrations were observed in the systemically infected hosts more than six weeks after application of the compounds. The growth reduction of pea plants caused by the virus infection could be partially abolished by the viral inhibiting activity of the compounds.
Differential Screening in a cDNA‐Library from Spruce for Clones Associated with Forest Decline Reveals Accumulation of Ribulose‐l,5‐Bisphosphate Carboxylase Small Subunit mRNA
Authors: Etscheid M. , Buschmann K. , Köhler R. , Köster S. , Riesner D. 
Published: May 2008

AbstractIn this work we identified mRNA species in spruce (Picea abiesL., Karst), which are expressed in altered concentration if the symptoms of forest decline are present. A cDNA library was constructed and ‘damage‐associated’ clones were identified by differential screening. A procedure for polyA+‐RNA preparation from needles of spruce was established which yielded a RNA fraction of sufficient purity for gel electrophoresis, hybridization and most importantly, for reverse transcription and the consecutive steps of molecular cloning. RNA isolated from a symptomless and a damaged tree was combined and a cDNA library in phageλgt 10 was constructed. Three series of differential screening were carried out. In the first series radioactively labeled cDNA samples were prepared from poly A+‐RNA from a symptomless tree and a damaged tree. Differential hybridization of 10,000 cDNA clones with the two different samples yielded 37 cDNAs with different levels of hybridization signals. In a second series samples for hybridization tests were prepared from a symptomless and from a damaged tree at three different seasons, July, September, and December. These six different samples were used to search for significant hybridization differences in 2,000 clones. Five clones could be identified which showed hybridization differences independent of the annual season. In a third series, we tried to differentiate between genetic variations of individual trees and differences solely induced by the damage. Two mixed samples were prepared, one from an ensemble of 10 symptomless and one of 10 damaged trees. Six cDNA clones could be identified, which exerted clear differences with the mixed probes from the symptomless ensemble and the damage ensemble, respectively. In Northern hybridizations the cDNA clones could be attributed to mRNAs of well defined length.After sequence analysis of the cDNA clones and homology search in a gene data bank two sequences could be identified. One clone codes for the small subunit of ribulose‐l,5‐bisphosphate carboxylase (Rubisco SS) and another for the subunit II of photosystem I. By quantitative Northern