bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pseudomonas fluorescens and Erwinia herbicola Reduce Wilt of Grasses Caused by Xanthomonas campestris pv. graminis
Authors: Schmidt Dorothea 
Published: May 2008

Abstract Pseudomonas fluorescens and Erwinia herbicola were isolated from Italian ryegrass surviving to infection by Xanthomonas campestris pv. graminis.They reduced symptom expression and mortality of young ryegrass plants when inoculated simultaneously with or prior to the parasite. Protection from wilt was a quantitative effect, depending on the ratio pathogenic/non‐pathogenic bacteria: it was good with 1/99, less with 10/90 and moderate to low with 50/50.The effect of preinoculation by leaf‐clipping with scissors contaminated by P. fluorescens or E. herbicola could be detected at least seven days after clipping and at a distance of 2 cm below the clipping level. Preinoculation of roots, or stem bases did not protect the plants from leaf infection by the parasite.
Phytoalexin Induction as a Factor in the Protection of Capsicum annuum L. Fruits Against Infection by Botrytis cinerea Pers.
Authors: Adikaram N. K. B. , Brown AverilE. , Swinburne T. R. 
Published: May 2008

AbstractImmature Capsicum annuum fruits treated at wound‐sites with glucans from the hyphal walls of Glomerella cingulata and incubated for 24 h or longer accumulated levels of capsicannol phytoalexins sufficient to inhibit rot development by Botrytis cinerea. Elicitor application to intact fruits induced the accumulation of relatively low levels of capsicannol compounds but further phytoalexin accumulation in fruits after wound‐inoculation with B. cinerea was much more rapid than in untreated fruits and rot development was suppressed.Capsicannol phytoalexins were produced in the live cells of the epidermis and little or no necrosis was associated with quantities produced in intact tissues. Elicitor treatment of intact fruits to protect against rot development by B. cinerea was achieved without the fruits sustaining unsightly damage.
Incidence of Three Major Cassava Diseases on Local Susceptible Cassava Cultivars at Three Planting Dates
Authors: Pacumbaba R. P. 
Published: May 2008

AbstractIncidence of African cassava mosaic (ACMD), cassava bacterial blight (CBB), and cassava anthracnose (CA) on local susceptible cassava cultivars planted in December, February, and April was investigated. December cassava planting had a higher incidence of ACMD, CBB, and CA diseases compared with February and April plantings. CA seemed to be more prevalent at an older stage (8 months old) of plant growth. April planting had significantly lower incidence of major cassava diseases, and higher mean tuber, yield than the same cassava cultivars planted earlier. The length of exposure of cassava plants to the inocula and/or to the vector during the rainy season determines the occurrence of diseases. In the absence of resistant cassava cultivars and through, partial disease escape of susceptible cultivars from ACMD, CBB, and CA, planting the same cultivars in April can still produce a profitable cassava crop.
Detection of Sap‐Transmissible Viruses by ELISA in Tissue‐Propagated Plants of Red Raspberry during in vitro Culture
Authors: Baumann Gisela , Theiler‐Hedtrich R. , Casper R. 
Published: May 2008

AbstractApple mosaic virus and raspberry bushy dwarf virus were detected by ELISA in plantlets of red raspberry still growing in vitro. The plantlets were derived from explants which were excised from plants infected by either of the viruses mentioned. Detection by ELISA of prune dwarf virus in 4‐month‐old in vitro cultures of sour cherry was reported earlier. Thus, application of ELISA to tissue cultured plants in vitro seems to be an appropriate method for early detection of virus‐infected plant cultures.
Increase of Free Space Solutes in Tobacco Leaves in Relation to the Localized Cellular Response Following Injections of a Bacterial Protein‐Lipopolysaccharide Complex*
Authors: Mazzucchi U. , Gasperini C. , Noli E. , Bonatti P. Medeghini 
Published: May 2008

AbstractVariations in pH, cell ultrastructure, conductivity, calcium ion molarity, reducing sugars, uronic acids and in protein of the intercellular washing fluid were studied at 0, 12, 24 and 48 h in tobacco leaf halves intercellularly injected with a bacterial pr‐LPS complex (250 μg‐ml−1). These injections induced a localized cellular reaction (LCR) in points opposite to intercellular structured deposits on the plant cell walls. The intercellular fluid pH was higher at 24 h than in the control, but not at 12 and 48 h. The conductivity, the calcium ion molarity, the free and hydrolyzed sugar content were higher at 12, 24 and 48 h than in the control tissue; the uronic acid content was higher at 24 and 48 h, but not at 12 h. There was a peak for, all 5 parameters at around 24 h, when LCR showed its highest activity. The protein content was significantly higher at 24 and 48 h than in the control intercellular fluid.The increase in conductivity, calcium ions, sugar, uronic acids and proteins in the intercellular fluids of the pr‐LPS injected tissue were interpreted as direct or indirect effects of the LCR, i.e. as an exocytosis induced by pr‐LPS injections. The associated high sugar and uronic acid content of the intercellular fluid at 12 and 24 h was not correlated to its capacity to prevent the hypersensitive confluent necrosis when injected intercellularly into tobacco tissue.
Cucumis sativus Cryptic Virus, a New Virus in Cucumber
Authors: Jelkmann W. , Maiss E. , Casper R. , Lesemann D. E. 
Published: May 2008

AbstractIsometric virus‐like particles (VLPs) have been purified from cucumber leaf tissue. Three dsRNA segments with estimated molecular weights of 1.8, 1.1 and 1.0 × 106d have been isolated from VLPs occurring in CsCl density gradient fractions but were also readily detected in preparations from as little as 1 g of fresh leaf tissue. The VLPs resemble dsRNA containing cryptic viruses and have been named Cucumis sativus cryptic virus (CsCV).
Pectolytic and Cellulolytic Activity of Botrytis cinerea Pers. Related to Infection of Non‐ripening Tomato Mutants
Authors: Barkai‐Golan Rivka , Lavy‐Meir Gila , Kopeliovitch E. 
Published: May 2008

AbstractEnzymes of Botrytis cinerea were detected in vitro using various carbon sources. Pectin‐pectate as a sole carbon source induced both polygalacturonase (PG) and pectin lyase (PL) activity, whereas carboxymethylcellulose served as an inducer for cellulase (Cx) activity. PG activity appeared earlier than Cx activity when induced by their respective sources. Both PG and PL activities were detected earlier and their level was higher on cell walls of the normal tomato fruit, than of the nor mutant, and in each case activity was higher on cell walls of the mature fruits than of the mature‐green ones. Whereas relatively high rates of PG and PL activity were recorded on autoclaved tomato homogenate (TH) of both the normal and the nor fruits, only trace levels of PG activity were recorded on unautoclaved media, except for those prepared from ripe normal fruits, and no PL activity was detected on either of the unsterilized media. Botrytis‐infection resulted in PG activity in the enzyme‐less rin and nor mutant fruits at both stages of maturity and in the normal and hybrid fruits at their mature‐green stage. In the ripe normal and hybrid fruits, infection increased the level of PG activity recorded prior to inoculation. An association was drawn between the low PG activity recorded in the nor mutant and its hybrid at initial stages of invasion and their resistance to infection.Following infection an increase in the level of Cx activity over that recorded in healthy fruits was found in all the tomato genotypes, whereas no PL was recorded in either healthy or infected fruits.
Cellulolytic Ability of the Scab Fungus, Venturia inaequalis
Authors: Wagner K. , Hitz‐Germann Luzia , Seng J. M. , Gessler C. 
Published: May 2008

AbstractCellulase and β‐D‐glucosidase activity have been identified in Venturia inaequalis, the causal agent of apple scab. Most of the activity of the enzymes was associated with the mycelium after homogenization. The activities were relatively weak in vitro compared to those of other plant pathogens. With a new screening technique, β‐D‐glucosidase hyperproducing mutants were obtained.
Rhabdoviruses in Mentha piperita
Authors: Intert F. , Amelunxen F. 
Published: May 2008

AbstractBacilliform and bullet‐shaped particles measuring 360 × 80 nm and 180x 80 nm respectively, were found in the perinuclear space of parenchymatous cells in the vascular bundles of leaves, or roots of Mentha piperita. All particles contained bullet‐shaped, electron dense cores and were enveloped by a unit membrane with spikes on its surface. The typical morphology and the intracellular occurrence of these particles leads us to the conclusion that they are rhabdoviruses.
Presence of Malformin‐Like Substances in Malformed Floral Tissues of Mango
Authors: Singh Zora , Dhillon B. S. 
Published: May 2008

AbstractMalformin‐A like substances were detected in malformed floral tissues of mango at four stages of development, viz., fully swollen buds, bud inception, fully grown panicles prior to full bloom and in panicles at full bloom. Spraying with 2000 ppm ascorbic acid, prior to flower bud differentiation significantly reduced the incidence of malformation and resulted in increased fruit yield.
Carbohydrate Composition and Acid Invertase Activity in Rice Leaves Infected with Pyricularia oryzae
Authors: Hwang Byung Kook , Kim Ki Deok , Kim Young Bae 
Published: May 2008

AbstractEthanol‐soluble carbohydrates in healthy and blast‐infected leaves and also cultures of Pyricularia oryzae were analyzed using gas chromatography. Arabitol, mannitol, and trehalose occurred in infected leaf tissue, but not in healthy controls. Cultures of P. oryzae contained mannitol and trehalose, but not arabitol and sucrose. The presence of arabitol only in blast‐infected rice leaves suggests that arabitol synthesis may be induced in infected leaf tissue as a result of the rice‐blast fungus interaction, but may not be within blast fungus itself. The amounts of glucose, fructose, and sucrose in infected leaves were slightly increased until 5 days, and greatly enhanced at 7 days after inoculation, There were no differences in amounts of these sugars between the cultivars Nakdong and Dobong. At 7 days after inoculation, increases in amounts of arabitol, mannitol, and trehalose were pronounced in the susceptible cultivar Nakdong than in the moderately susceptible cultivar Dobong. The increased amounts of glucose and fructose in infected plants of the two cultivars were closely correlated with the presence of a very active invertase.
Influence of Phospholipids on Growth, Sporulation and Virulence of the Endoparasitic Fungi Drechmeria coniospora, Verticillium balanoides and Harposporium anguillulae in Liquid Culture
Authors: Lohmann Ulrich , Sikora Richard A. , Höfer Milan 
Published: May 2008

Abstract Verticillium balanoides mycelial growth was stimulated on solid corn meal agar (1.7 %) and in liquid corn meal broth (0.2 %) upon the addition of phospholipids at various concentrations. Sporulation differed with phospholipid products and was highest in pure corn meal. Drechmeria coniospora mycelial growth increased upon addition of phospholipids at all concentrations in solid or liquid culture. Sporulation increased at high concentration (1000 ppm) and decreased at low concentration (100 ppm) of phospholipids in the medium. For both fungi, infectivity of conidia produced in liquid culture decreased when compared to conidia from parasitized nematodes. Addition of phospholipids partly restored this effect. Harposporium anguillulae mycelial growth and sporulation was not affected by addition of phospholipids to solid or liquid corn meal medium.
Bodenbewohnende Schädlinge und Seitenwurzelfäule der Zuckerrübe in Abhängigkeit von der Rotation – Ergebnisse eines Fruchtfolgeversuches
Authors: Schäufele W. R. , Winner C. 
Published: May 2008

AbstractSoil inhabiting pests and rot of feeding roots of sugar beet depending on rotation ‐ Results of a long‐term trialOver a period of 17 years a trial was carried out with sugar beet, cereals and oilseed rape in different crop rotations on a field near Göttingen (Lower Saxony). The frequency of sugar beet in the rotation was 17, 25, 33 and 67 %.In absence of beet nematodes, root and sugar yield of the beet decreased after repeated growing of sugar beet in short rotations compared to variants with long rotations. Sugar content and beet quality were only slightly influenced.By applying a bioassay (BW‐Test) with young beet plants in the greenhouse it was shown that increasing infections on the tips of rootlets of the beet plants were the cause for decreasing beet yield in close rotations. Mortality of young beet plants and progress of infection in the test indicated roughly the quantity of pathogenic fungi in the soil. In the roots of the bait platits the parasitic fungus Aphanomyces cochlioides predominated.Rate of infection and yield reduction in the field were decisively influenced by weather conditions. Differences in yield between sugar beet grown in a three‐year and a four‐year rotation, however, were not significant.An occurrence of beet pests depending on crop rotation was stated only for Atomaria linearis and this only in a few years.
Occurrence of Aggregate Sheath Spot of Rice in Iran
Authors: Rahimian H. 
Published: May 2008

AbstractAggregate sheath spot of rice caused by Rhizoctonia oryzae‐sativae (Swa.) Mordue was found in several locations in Mazandaran Province. The polyacrylamide gel electrophoretic pattern of cell proteins of isolates from different regions were identical. The protein profiles of Iranian isolates were also identical with that of an anastomosis group (AG)‐Bb tester isolate of binucleate Rhizoctonia from Japan, but distinctly different from an AG‐Ba tester strain.
ACC Synthesis as the Activated Step Responsible for the Rise of Ethylene Production Accompanying Citrus Exocortis Viroid Infection in Tomato Plants
Authors: Bellés J. M. , Granell A. , Durán‐vila N. , Conejero V. 
Published: May 2008

AbstractEthylene production was stimulated during the period when systemic symptoms appeared in tomato plants infected with citrus exocortis viroid (CEV).Neither methionine nor S‐adenosylmethionine increased ethylene production in leaf discs. In contrast, 1‐aminocyclopropane‐l‐carboxylic acid (ACC) stimulated ethylene production notably. Whether viroid infection acted upon ACC production, its conversion to ethylene, or both, was studied by determining the time course of the concentration of ACC and its in vivo production and conversion rates. During early symptoms, ACC synthesis increased and then remained steady during the development of symptoms, but no difference in the capacity of conversion of ACC to ethylene between healthy and CEV‐infected tissues was observed. This indicates that ethylene production in tomato leaves showing systemic symptoms to CEV is activated at the level of ACC production.
Structure‐Biological Activity Relationships in Alfalfa Antimycotic Saponins: The Relative Activity of Medicagenic Acid and Synthetic Derivatives Thereof Against Plant Pathogenic Fungi1
Authors: Levy M. , Zehavi U. , Naim M. , Polacheck I. , Evron R. 
Published: May 2008

AbstractThe antimycotic activity of medicagenic acid and of some synthetic derivatives thereof was tested against plant pathogenic fungi. In general they all possess antimycotic activity. Furthermore, in the case of Sclerotium rolfsii, compounds where the hydroxyl functions of the aglycon remained unchanged (medicagenic acid and its dimethyl ester) or could be enzymically released (3‐0‐β‐D‐glucoside of medicagenic acid dimethyl ester) were significantly more active than compounds where these functions were modified by acetylation or methylation.Selective 2‐0‐methylation of medicagenic acid and comparison of the antimycotic activity of the resulting derivative against S. rolfsii to that of other derivatives suggests that a potential free hydroxyl at position 3 is essential to antimycotic activity.
Changes in Cell Size and Flagellation in the Phytopathogen Pseudomonas syringae pv. tabaci Cultured in vitro and in planta: A Comparative Electron Microscope Study
Authors: Sigee D. C. , El‐Masry M. H. 
Published: May 2008

AbstractIn parallel experiments, cells of Pseudomonas syringae pv. tabaci were infiltrated into tobacco leaves (to determine bacterial changes occurring in planta) and inoculated into nutrient broth (to make comparative observations on cells cultured in vitro). In each case, details of surface structure, bacterial size and flagellation were determined in a sequence of samples by transmission electron microscopy of whole mount stained and unstained preparations.In both in planta and in vitro environments, bacterial population showed a clear phase of exponential increase. In each case, bacterial size was highest during the early part of the multiplication phase, then decreased during the rest of the multiplication period. In each case also, the proportion of cells with flagella showed a similar trend ‐ with an initial decrease after infiltration, followed by a major increase during the phase of bacterial multiplication. These results suggest that changes in bacterial size and flagellation in planta relate directly to the growth phase of the population, and are therefore determined primarily by internal cellular (endogenous) factors ‐ rather than by external factors within the leaf environment.
Occurrence and Identification of Eggplant Mottled Crinkle Virus in India
Authors: Raj S. K. , Aslam M. , Srivastava K. M. , Singh B. P. 
Published: May 2008

AbstractA virus isolated in India from eggplant (Solanum melongena) showing chlorotic rings, line pattern and mosaic on leaves accompanied with stunted growth was identified as a strain of eggplant mottled crinkle virus on the basis of host range, in vitro properties, particle morphology, molecular weight of capsid protein and serological relationship. The sodium dodecyl sulfate‐polyacrylamide gel electrophoresis of virus coat protein revealed the presence of a single polypeptide with a molecular weight of 41,000. An antiserum to the virus produced in rabbit had a titre of 1: 2048 in double diffusion tests.
Characterization of a Latent Elongated Virus from Globe Artichoke (Cynara scolymus L.) in Italy
Authors: Rana G. L. , Piazzolla P. , Lafortezza R. , Greco N. 
Published: May 2008

AbstractA virus with filamentous particles was isolated from symptomless plants of Cynara scolymus cvs Romanesco and Terom obtained by in vitro meristem culture in northern Italy. The virus was characterized biologically, physico‐chemically and serologically. The cytopathology induced by its infection in two artificial hosts (Chenopodium quinoa and Nicotiana benthamiana) was also investigated. The virus has slightly flexuous elongated particles measuring 12 ± 664 nm; its sedimentation coefficient, RNA content, mol. wts. of RNA and coat protein subunits are 150 S, 6 %, 2.2 × 106 and 2.9 × 104, respectively. In microprecipitation tests, it resulted serologically related to poplar mosaic virus (PopMV) (SDI = 4–5). Cellular inclusions and cytopathology observed in both the artificial hosts conform to those of the carlavirus group.
Phytophthora and Pythium in Pot Plant Cultures Grown on Ebb and Flow Bench with Recirculating Nutrient Solution
Authors: Thinggaard K. , Middelboe A. L. 
Published: May 2008

AbstractThe occurrence of pythiaceous fungi in pot plant cultures grown in ebb and flow bench systems was investigated monthly from May to December, Phytophthora, Pythium and Saprolegnia (in all 351) were isolated from water samples and identified. Nearly all the isolates of Pythium produced zoospores in water.A pathogenicity test involving 15 isolates of Pythium“group P”, and 7 of Pythium“group F” showed that 73 % were pathogenic on cucumber, 66 % on Gerbera, 59 % on lettuce, 50 % on tomato, and 32 % on cress. Control of Pythium and Phytophthora is important in order to improve the health of plants grown in ebb and flow systems.
Ultrastructural Studies of Zoosporangium and Resting Sporangium of Synchytrium desmodii
Authors: Lange Lene , Lenné Jillian M. , Olson Lauritz W. 
Published: May 2008

AbstractThe development of the zoosporangium and resting sporangium of Synchytrium desmodii, the causal agent of the wart disease of Desmodium is described. During zoosporangium development synaptonemal complexes are formed. (The presence of synaptonemal complexes is characteristic for pachytene of the first meiotic nuclear division.) Zoospore differentiation and maturation in zoo‐sporangia within the same sorus is asynchronous. Prosorus formation was not observed and it is suggested that previous descriptions of a prosorus in S. desmodii may have been based on observations of an empty collapsed zoosporangium. The resting sporangium of S. desmodii is ultrastructurally similar to that observed for S. endobioticum, S. mercuralis and S. anemones. The mature resting sporangium contains a single centrally located nucleus, a large amount of reserve material (lipid) and is surrounded by an extremely thick multilaminate wall which may be up to 15 μm in thickness.Germination studies of surface sterilized seeds of Desmodium and seeds contaminated with resting sporangia of S. desmodii did not lead to plants infected with S. desmodii and thus no conclusion can be made about whether the wart disease of Desmodium can be seed transmitted but only that resting sporangia of S. desmodii may be found on the surface of seeds harvested from naturally infected fields.
Purification and Serology of the Iranian Maize Mosaic Rhabdovirus1)
Authors: Izadpanah K. 
Published: May 2008

AbstractLeaves of maize infected with the Iranian maize mosaic rhabdovirus (IMMRV) were homogenized in 0.1 M citrate‐0.04 M Na2SO3 buffer, pH 5.4, containing 10 % sucrose and the extract was subjected to low speed and high speed centrifugation followed by resuspension in 0.05 M potassium phosphate buffer, pH 7.2, containing 10 % sucrose. Partially purified preparation was obtained by density‐gradient centrifugation, removal of the virus zones and their concentration by high speed centrifugation. Two virus specific bands were observed in density‐gradient columns. An antiserum with a titer of 128 was prepared by injecting partially purified virus into rabbits. In agar‐gel‐diffusion tests, the antiserum produced one or two precipitin lines against diseased maize extract but none against healthy maize extract. IMMRV was not related to barley yellow striate mosaic (BYSMV), cereal chlorotic mottle (CCMV), Cynodon chlorotic streak (CCSV), Festuca leaf streak, and maize mosaic (MMV) viruses as well as to two unidentified rhabdoviruses occurring in wheat and Bermuda grass in the vicinity of Shiraz, when these viruses were tested against IMMRV antiserum in agar‐gel‐diffusion and enzyme‐linked immunosorbent assay. Likewise, IMMRV did not react with antisera to BYSMV, CCMV, CCSV and MMV in agar‐gel‐diffusion tests. IMMRV appears to be different from most reported rhabdoviruses of cereals.