bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pathogenicity of Race‐1 and Race‐2 Tomato Wilt Isolates of Verticillium dabliae to Four Solanaceous and Two Non‐Solanaceous Hosts
Authors: Mingochi D. S. , Clarkson J. M. 
Published: May 2008

AbstractThe pathogenicity of four race‐1 and three race‐2 tomato with isolates of Verticallium dahliae to tomato, eggplant, tobacco, pepper, French bean and cabbage was investigated. Plants were inoculated without wounding and the symptoms assessed 6, weeks later. Both race‐1 and race‐2 isolates caused foliar symptoms on the race‐1 susceptible tomato cultivar GCR‐26 (Ve/Ve) although these were generally more severe with race‐1. All race‐2 isolates were significantly more pathogenic than race‐1, on the race‐1 resistant tomato cultivar GCR‐218 (ve/ve), although two of the race‐1 isolates caused mild foliar symptoms. None of the race‐2 isolates caused stunting of GCR‐26 whereas they all caused significant stunting of GCR‐218. All isolates reduceddry weight on GCR‐26 whereas only race‐2 affected GCR‐218. All isolates induced significant foliar symptoms, stunting and reduction in dry weight on eggplant. Only one isolates (race‐1) caused foliar symptoms on tobacco but this was not accompanied by areduction in either plant height or dry weight. All isolates were able to cause foliar symptoms on pepper, and two caused moderate to severe symptoms. Four isolates caused a significant reduction in plant height and one of these reduced dry weight. One isolates which caused mild foliar symptoms on papper increased host dry weight. No disease symptoms were observed on the non‐solanaceous host French bean. All isolates were capable of inducing mild foliar symptoms on cabbage but none caused reductions ineither plant height or dry weight. Race‐1 and race‐2 isolates could only be distinguished on the near‐isogenic pair of tomato cultivars. Verticallium was re‐isolated for each fungal isolate/host cultivar combination for tomato, eggplant and tobacco but was sporadic for the other hosts.
Spread of Erwinia chrysanthemi in Kalanchoë blossfeldiana
Authors: Bech K. 
Published: May 2008

AbstractMeristems were excised from young and 8‐month‐old Kalanchoë blossfeldiana naturally‐infected with Erwinia chrysanthemi (Echr). From heavily infected plants the bacteria were identified in meristems from the very top of the plant as well as from meristems situated lower on the plant. In other naturally‐infected plants Echr was only found at the stem base, depending on how advanced (old) the infection was. Repetition of identification on meristem samples stored in the refrigerator for1 week revealed more positive samples than in the first test. Infection trials showed a quick spread of bacteria from stem base to apex via xylem vessels in some of the inoculated plants. Spread of Echr via capillary mats from inoculated to non‐inoculated Kalanchoë plants were found after 5.5 months growth on the capillary mat. The time lapse before transmission may vary with the seasons of the year.
Changes in Peroxidase Activity in Bean Suspension Cultures after B. cinerea and Elicitor Treatment
Authors: Malolepsza U. , Urbanek H. 
Published: May 2008

AbstractTreatment of cell suspension cultures of bean (Phaseolus vulgaris) c.v. ‘Gold Saxa’) with Botrytis cinerea resulted in the increase in extra‐ and intracellular peroxidase activity. A similar effect was obtained by treatment of cell suspension cultures with an elicitor active extract from fungal mycelium.It was shown by means of electrofocusing that the infection‐ or elicitor‐related increase in total intracellular peroxidase activity was associated with the increase in the activity of a specific isozyme with an isoelectric point of 4.8. This anionic peroxidase did not differ in substrate specificity to guaiacol, syringaldazine and chlorogenic acid.
Virus Content and Virulence of Polymyxa betae Keskin Isolates Obtained from Different Regions in Europe
Authors: Kastirr U. , Pfeilstetter E. , Burgermeister W. 
Published: May 2008

Abstract Polymyxa betae isolates were obtained by means of bait plants from a large number of soil samples collected in eastern Germany. Additional P. betae isolates were received from several institutions in western Germany and abroad. Isolates were grown on sugarbeet seedlings and tested for the presence of beet necrotic yellow vein virus (BNYVV) and beet soilborne virus (BSBV). BNYVV was only present in isolates from western Germany and abroad but absent in all isolates from eastern Germany., In contrast, BSBV was detected in more uniform geographic distribution in 14 out of 33 P. betae isolates tested. The virulence of P. betae isolates was estimated on the basis of the extent of resting spore formation in the root system of sugarbeet seedlings. Differences in virulence were found among virus‐free as well as virus‐carrying P. betae isolates. The mean value of virulence ratings was distinctly lower with BNYVV‐carrying isolates and slightly lower with BSBV‐carrying isolates as compared to virus‐free isolates.
Restriction Fragment Length Polymorphisms Within the Apple Proliferation Mycoplasmalike Organism
Authors: Kison H. , Schneider B. , Seemüller E. 
Published: May 2008

AbstractGenetic homogeneity of the mycoplasmalike organisms (MLOs) associated with apple proliferation (AP) disease was examined by comparing samples collected in south‐western Germany, France, Italy, and Romania by Southern blot analysis. The material examined consisted of two periwinkle‐maintained strains of the AP‐MLO, samples from witches' brooms of 48 symptomatic trees, and root samples from 14 latently infected trees. Six cloned chromosomal DNA fragments of one of the periwinkle‐maintained strains were used as probes. These probes, which were specific for the AP‐MLO and other European fruit MLOs, hybridized with DNA of all samples which indicates that the MLO5 examined were closely related with one another. However, restriction fragment length polymorphism was common bands. Therefore, the AP agent can be regarded as a taxonomic entity. The variability among the isolates seems not to due to their geographical origin but might be related to pathological traits.
Adenosine/Adenine‐Containing Nucleotides in the Leaves and Roots of Young Barley Plants after Infection of the Primary Leaf by Erysiphe graminis
Authors: Schmidt G. , Boyle C. , Aust H. J. , Wagner K. G. 
Published: May 2008

AbstractThe levels of adenosine, the adenine nucleotides AMP, ADP, ATP, as well as NAD, NADP, protein and chlorophyll were determined in young barley plants of which the primary leaves were infected by Erysiphe graminis DC. f. sp. hordei MARCHAL. The largest changes of these metabolite levels, compared to the non‐infected control, occurred in the infected leaf and to a lesser degree also in the roots and in healthy younger leaves. The increase in the levels of most metabolites in the primary leaf revealed the sink property of this infected tissue and possible stress or defence reactions of the host, whereas the reductions in the roots showed the impaired supply of this natural sink organ due to the infection. Changes in the healthy leaves were most pronounced in the tertiary leaf and may reflect metabolic stimulation in that healthy organ. The changes of the adenosine pool, a precursor of the adenine nucleotides, were discussed in terms of translocation and its possible role as a precursor for fungal purine nucleotide synthesis.
Sources of Resistance to Common Bunt (Tilletia foetida and T. caries) in Durum Wheat
Authors: Mamluk O. F. , Nachit M. M. 
Published: May 2008

AbstractScreening of durum wheat germplasm for resistance to common bunt (Tilletia foetida and T. caries) resulted in the identification of 26 resistant genotypes. The screening was made using nine common bunt isolates from the West Asia and North Africa (WANA) region. In one isolate the two pathogens were represented in ratio of 1:1, whereas eight isolates contained only T. foetida. The correlation, principal components and clustering analyses grouped the genotypes into three clusters., Cluster one comparised genotypes close to Senatore (S.) Cappelli and Haurani, the latter is a landrace from Syria. Cluster three comprised advanced genotypes containing resistance genes from Mindum, a Turkish landrace. Results indicated that donor sources of resistance appear to be related to the three major sources mentioned. Cultivar S. Cappelli is considered resistant since it has been grown by farmers on a large scale for many years and remained resistant to common bunt throughout 7 years of testing. This resistance is assumed to be of a durable type. The isolates were also grouped into three clusters representing different ecological areas and the wheat types from which the isolates originated. We infer that the different clusters reflect the presence of three pathotype groups of the pathogens.
Evaluation of Some Fungi and Bacteria for Potential Control of Safflower Rust
Authors: Tosi L. , Zazzerini A. 
Published: May 2008

AbstractSome fungal and bacterial isolates applied as soil and seed treatments in greenhouse trials gave a good protection against Puccinia carthami Cda. on safflower, significantly reducing the infection from rust‐infested seeds. Trichoderma viride and T. harzianum added alone and in combination as air‐dried inoculum to the soil were the most effective fungal isolates. However T. viride at two higher rates reduced the rate of emergence of safflower seedlings.Among bacteria, Bacillus subtilis, B. cereus, isolates of Pseudomonas fluorescens and B. thuringiensis reduced rust infection when added both as soil drench and as seed treatment.Good results in the biocontrol of P. carthami were also obtained with some combination antagonist treatments such as T. viride + B. cereus, T. viride + P. fluorescens (16), T. viride + T. harzianum + B. cereus and T. viride +, T. harzianum + P. fluorescens (16).Fungal isolates added as soil treatment increased seedling length, whereas no similar effects were observed when these isolates were applied as seed treatment.
Rapid Differentiation of Soybean Mosaic Virus Isolates by Antigenic Signature Analysis
Authors: Hill J. H. , Benner H. I. , Van Deusen R. A. 
Published: May 2008

AbstractAntigenic differences among 14 soybean mosaic virus (SMV) isolates were shown by signature analysis employing a panel of nine well‐characterized monoclonal antibodies. Sets of binding curves were generated by reacting aliquots of serial dilutions of leaf extracts from soybean plants infected with each strain of SMV simultaneously with each antibody in the panel. An iterative alignment procedure allowed comparison of binding profiles from different assays in which the starting concentrations of SMV antigen were unknown. Desiccation of infected soybean leaf tissue altered antigenic signatures by inducing changes in reactivity of epitopes recognized by certain antibodies. The method was useful for the elucidation of subtle antigenic differences amongSMV strains. The procedure requires a minimum amount of tissue processing, the analysis is rapid and sensitive, and it requires neither purification nor knowledge of concentration of virus in ground leaf tissue from infected plants.
Differential Interaction Between PAV‐like Isolates of Barley Yellow Dwarf Virus and Barley (Hordeum vulgare L.) genotypes
Authors: Chalhoub B. A. , Sarrafi A. , Beuve M. A. , Lapierre H. D. 
Published: May 2008

AbstractFour PAV‐like isolates of barley yellow dwarf virus (BYDV) were identified as causing very severe (RG), severe (2t), moderately severe (3b) and mild symptoms (13t) in barley (Hordeum vulgare) cultivar Plaisant in a growth chamber at 25 days after inoculation. These isolates had different effects on a range of barley genotypes. Cultivar Vixen, which contains the Yd2 resistance gene, and 80‐81 BQCB10 were not affected by any isolate. Five other genotypes were significantly affected by at, least one of the isolates. Line Ea52 (which is a mutant of the Japanese cultivar Chikurine Ibaraki) was more susceptible to BYDV‐PAV than Chikurin Ibaraki 1.No serological differences were detected between the four isolates using monoclonal or polyclonal antibodies. Virus antigen concentration, estimated by enzyme‐linked immunosorbent assay (ELISA), was correlated with the decrease in the shoot fresh weight for all isolates and all genotypes except for Vixen and 80‐81BQCB10.In field tests, the severity of symptoms induced by the BYDV‐PAV isolates was in accordance with that estimated in the growth chamber. However isolate 2t was more severe on cultivar Vixen and overcame the partial resistance of Chikurin Ibaraki 1 to the three other isolates.The results show that virus antigen concentration not only contributes to characterizing the resistance levels of barley genotypes but also the severity of BYDV‐PAV isolates.
The Grouping of Strains of Pseudomonas syringae subsp. savastanoi by DNA Restriction Fingerprinting
Authors: Mugnai L. , Giovannetti L. , Ventura S. , Surico G. 
Published: May 2008

AbstractA selected group of strains of Pseudomonas syringae subsp. savastanoi from olive, oleander and ash were compared with pathogenicity tests and with DNA restriction fingerprinting using sodium dodecyl sulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE) and silver staining. The strains from each host were distinguishable by their pathogenicity to the same host and to the other two plant species. A division into the same groups was obtained with unweighted pair‐group method with averages (UPGMA) clustering of the data from genomic fingerprinting, even though high overall similarity between the strains also indicated that they formed a single, well characterized taxon. It seems clear that the subspecies savastanoi of P. syringae comprises at least 3 groups of strains that differ in their precise host range, in the nature of the symptoms induced on the individual hosts, and in their genomic profile.
Interaction of Partially Purified Phytotoxins from Phytophthora cactorum on Apple Cell Plasma Membrane
Authors: Mezzetti B. , Capasso R. , Evidente A. , Hammerschlag F. A. , Zimmerman R. H. , Cristinzio G. , Rosati P. 
Published: May 2008

AbstractThe ‘crude’ filtrate (CF) of Phytophthora cactorum containing phytotoxin(s), having some properties similar to the toxins isolated from other Phytophthora species, was processed by three steps (acetone precipitation, dialysis and gel filtration chromatography). The CF fractions corresponding to the progressive steps of purification were tested for phytotoxicity on tomato sedlings and for activity on cell trans‐membrane electrical potential (Em) of susceptible and resistant apple root stocks (Malus domestica).The fractions (F4), obtained from chromatography on Sephadex G50 fine and eluted in the zone corresponding to a molecular weight of 15 ± 2kD, induced a specific alteration on susceptible apple cell membranes. These metabolites, even though incompletely purified, are able to induce a high and specific activity on susceptible apple cell Em only, not on resistant ones. As a consequence, they may be of potential use in screening for insensitive cells.
Effect of Herbicides on the Toxicity of Fungicides Against Rhizoctonia solani Causing Damping‐off of Cotton
Authors: Omaima A. Awadalla , Ilham M. El‐Refaie 
Published: May 2008

AbstractThe effect of two herbicides (paraquat and simazine on the antifungal activity of two fungicides (captan and mounsrin) against Rhizoctonia solani was studied. when the herbicides paraquat and simazine were applied to soil they altered the effectiveness of both fungicides in controlling R. solani, thus causing damping‐off of cotton. Both herbicides increased the toxicity of both fungicides against mycelial growth of the fungus. In pot tests, seeds or soil treated with captan or mounsrin, gave better control of R. solani damping‐off disease when the soil was treated with paraquat or simazine compared to untreated soil. Captan was, however, found to be more effective in controlling the disease than mounsrin.
Antagonistic Activity in Fusarium acuminatum
Authors: Logrieco A. , Mule G. , Bottalico A. 
Published: May 2008

AbstractTen of 19 (53%) tested isolates of Fusarium acuminatum, from different geographical origins and sources, showed in vitro antagonistic activity (inhibition at distance) to mycelial growth of F. moniliforme. Moreover, when F. acuminatum ITEM‐728 was tested against 25 different fungal species, an initial inhibition at a distance was observed which was followed by the spread of the F. acuminatum mycelium over the opposite fungal colony to various degrees. Most of the F. acuminatum isolates which showed antagonistic activity proved to be enniatin B (EB) producers, and some of them also formed moniliformin (MF). The toxic activity of the methanol extract of F. acuminatum ITEM‐728 towards some test microorganisms was closely related to the EB concentration. In particular, Bacillus subtilis proved to be a very sensitive test microorganism.
Production, Characterization, and Use of Monoclonal Antibodies Against Acremonium coenophialum
Authors: Scott S. W. 
Published: May 2008

AbstractMonoclonal antibodies were produced using intact mycelium of the fungus Acremonium coenopbialum as the immunogen. During the initial stages of characterization, the antibodies were found to react to A. coenophialum, A. loliae, Epichloe typhina, and also to cross‐react with some other fungi normally associated with tall fescue. Careful selection of the ELISA system in which the antibodies were used eliminated reactions to all but the two Acremonium spp. and E. typhina. Asa result it was possible to detect Acremonium spp. (presumably A. coenophialum) sensitively and unambiguously in leaf tissue of tall fescue.
Water Stress in Leaves of Pbaseolus vulgaris Infected with Xanthomonas campestris pv. phaseoli
Authors: Goodwin P. H. , Sopher C. R. 
Published: May 2008

AbstractInfection of bean leaves (Phaseolus vulgaris) by Xanthomonas campestris pv. phaseoli in the field frequently resulted in the appearance of isolated flaccid areas in green leaf tissue adjacent to necrotic and chlorotic lesions. The flaccid leaf areas had significantly higher stomatal resistances compared to nearby turgid areas on the same leaf, and the turgid areas had stomatal resistances that were the same or only moderately elevated compared to those of healthy leaves. The flaccid tissues also had significantly lower relative water contents than turgid tissues on the same leaf demonstrating that pathogeninduced water stress was localized. The levels of free proline, another indicator of water stress, were directly correlated (r2= 0.556) with disease severity. The change in free proline content implied that water stress increased in direct proportion with the amount of tissue infected. Water stress may be due to the disruption of xylem elements by the invasion of X. c. phaseoli from nearby lesions. One result of xylem invasion could have been severe water deficits which were sufficient to cause stomatal closure and leaf flaccidity; however, this effect was highly localized and the remainder of the diseased leaf was either significantly less water stressed or not affected.
Effects of Temperature and Leaf Weness on the Latent Period of Rbynchosporium Secalis (Leaf Blotch) on Leaves of Winter Barley
Authors: Davis Helena , Fitt B. D. L. 
Published: May 2008

AbstractEffects of temperature and leaf wetness on the latent period of Rhynchosporium secaits (leaf blotch) on winter barley were examined in controlled environment experiments. At 100% relative humidity (continuous leaf wetness) the mean length of the latent period was c.24 days at 5°C, c. 19 days at 10°C, c. 16 days at l5°C and c. 13 days at 20°C. The mean number of days between the appearance of the first and the last lesions was c. 13 days at 5°C, c. 6 days at 10°C, c. 5 days at 15°C and c. 3 days at 20°C. A negative curvilinear regression of latent period on temperature accounted for 99% of the variance. The mean area of lesions per leaf was 38 mm2 at 5°C, 46 mm2 at 10°C, 24 mm2 at 15°C and 24 mm2 at 20°C. At 10°C, after a 48 h wet infection period, the interruption of leaf wetness for 5 or more days at any time during the next 15 days of the latent period did not decrease subsequent lesion area. However, absence of leaf wetness after these 15 days, at the onset of sporuiation, did decrease the area of lesions which developed.
Multiplication of Xanthomonas campestris pv. Phaseoli and Intercellular Enzyme Activities in Resistant and Susceptible Beans
Authors: Goodwin P. H. , Sopher C. R. , Michaels T. E. 
Published: May 2008

AbstractIn order to assess resistance to common bean blight, populations of two isolates of Xanthomonas campestris pv. phaseoli were monitored in leaves of two Phaseolus vulgaris breeding lines, BLT87‐2 (susceptible) and OAC88‐1 (partially resistant) and a resistant tepary bean accession, P. acutifolius P. I. 440795. The breeding line OAC88‐1 possesses resistance to common bacterial blight which was incorporated from P. acutifolius by an interspecific cross. In susceptible, leaves, bacterial populations increased to 108 CFU/g leaf at 3 wk after inoculation whereas, in resistant leaves, bacterial populations declined to 101 ‐ 103 CFU/g leaf. In partially resistant leaves the population first declined similar to that in resistant P. acutifolius but later increased, and typical bacterial blight symptoms appeared. Cellulase, protease and amylase activities were monitored in culture and intercellular leaf spaces. Only cellulase activity was, clearly related to bacterial growth in the susceptible host; other enzyme activities were variable in their relationship to host resistance and bacterial growth. Differences between strains in cellulase activity inside partially resistant leaves corresponded to their ability to secrete cellulase in culture. Measuring cellulase activity in intercellular wash fluids may be a simple and sensitive method for determining X. c. phaseoli populations in leaves.
The Genetic Relationship Between Mycoplasma‐like Organisms Causing Diseases in the Sudan and Different Continents Revealed by Polymerase Chain Reaction (PCR) Amplification of the 16S rRNA Gene Followed by Restriction Fragment Length Polymorphism Analysis
Authors: Saeed E. M. , Cousin M. T. 
Published: May 2008

AbstractThe genetic relationship between faba bean (Vicia faba L.) phyllody and other mycoplasma‐like organism (MLO) diseases has been studied by amplification of the conserved region of the 16S rRNA gene followed by restriction fragment length polymorphism (RFLP) analysis using Alu I restriction endonuclease. The restriction patterns produced by faba bean phyllody MLO were smilar to that of Crotalaria saltiana phyllody MLO which persists throughout the year in the Sudan. These, and serological results clearly confirmed that C. saltiana is a reservoir of faba bean phyllody MLO in the Sudan. Moreover, restriction patterns have also shown that MLOs of other diseases have the same RFLP fragment pattern as faba bean phyllody MLO, including C. juncea witches'broom (Thailand) and tomato big‐bud (Australia), which differs from the other selected MLO diseases (Gladiolus aster yellow, clover phyllody and yellow decline of lavender, aqll from France).Fragment patterns also revealed the existence of genetically diverse MLO strains in the Sudan. Faba bean phyllody may be placed in group III including WX, apricot chlorotic leaf roll, golden flaveswcence dorée of grapevine, plum leptonecrosis of Prunus salciana, peachy yellow leaf roll, sunnhemp phyllody from Thailand, and blueberry witches' broom.