bluuebunny/crossref_metadata_2025 huggingface dataset:
A Simple DNA Extraction Method for PCR‐based Detection of Xanthomonas campestris pv. pelargonii in Geraniums
Authors: Sulzinski M. A. , Moorman G. W. , Schlagnhaufer B. , Romaine C. P.
Published: May 2008

A simple method for PCR‐based plant clinical diagnosis of bacterial blight of geraniums caused by Xanthomonas campestris pv. pelargonii is described. The method entails maceration of infected tissues in water or 10mM Tris‐ HCI, pH 8.0 buffer, followed by treatment of the macerate with a commercially‐available extraction matrix (GeneReleaserTM) in which nucleic acid is released by brief microwave heating. Nucleic acid prepared in this manner served directly as template for PCR amplification with primers targeting a sequence in the genome of the bacterium. Using this protocol, it was possible to quickly identify X. campestris pv. pelargonii in infected geraniums, whereas amplification products were not obtained with nucleic acid preparations from noninfected plants, or from plants infected with the bacterial pathogens, Corynebacterium fascians or Pseudomonas cichorii.
Infectivity of Chlamydospores vs Microconidia of Fusarium oxysporum f.sp. lycopersici on Tomato
Authors: De Cal A. , Pascual S. , Melgarejo P.
Published: May 2008

The effect of nature of inoculum on disease induced by Fusarium oxysporum f.sp. lycopersici on tomato was tested. Chlamydospores produced in soil 30 days after inoculation induced a more severe disease than microconidia indicating a higher inoculum potential of chlamydospores.

The method proposed produces easily an inoculum of F. oxysporum f.sp. lycopersici which infects the plants consistently and induces a relatively high disease severity.
Use of the Reverse Transcription‐Polymerase Chain Reaction for the Detection of Pelargonium Flower Break Carmovirus
Authors: Franck A. , Loebenstein G. , Gera A.
Published: May 2008

A polymerase chain reaction (PCR)‐based assay was used to detect pelargonium flower break carmovirus (PFBV) in total RNA extractions made from infected Pelargonium plants. Extracts were reverse transcribed (RT) and the resultant cDNA was amplified by PCR, using oligonucleotide primers specific for 343, 510 and 832 base pair fragments of the RNA‐dependent RNA polymerase gene of PFBV.

The specificity and sensitivity of RT‐PCR were compared with the enzyme‐linked immunosorbent assay (ELISA) for the detection of PFBV in Pelargonium tissues. The virus could be detected efficiently in high dilutions of sap from infected plants and at low concentrations of purified virus. Although ELISA is a powerful tool for virus detection, RT‐PCR was over 1000 times more sensitive in detecting PFBV in leaf extracts of infected Pelargonium than was ELISA. The limit of detecting PFBV RNA by RT‐PCR was 200 fg, compared with 200 pg of virus by ELISA.
Cytopathological Responses of Picea abies Seedling Roots Challenged in vitro by a Necrotrophic Fusarium avenaceum (Fr.) Sacc.
Authors: Asiegbu F. O. , Johansson M. , Daniel G.
Published: May 2008

Interaction of the necrotroph Fusarium avenaceum with seedling roots of Norway spruce was studied. The results showed that Norway spruce seedlings were susceptible to the pathogen but disease progression and severity was dependent on inoculum potential. Host recognition of the pathogen marked by hypersensitive browning reactions occurred late, thus making successful resistance to cellular damage impossible. Such host resistance responses were mostly in the form of lignification, accumulation of electron dense materials and papillae formation.
The Infection Court of Faba Bean Seedlings for Oospores of Peronospora viciae f.sp. fabae in Soil
Authors: van der Gaag D. J. , Frinking H. D.
Published: May 2008

The infection court of Faba bean seedlings for oospores of Peronospora viciae f.sp. fabae in soil was determined. Soil naturally infested with oospores was placed as 3‐cm thick layers at four different depths relative to Faba bean seeds. Seedlings with downy mildew were obtained only from seeds sown in the middle of a 3‐cm layer of oosporeinfested soil. No infection was obtained from oosporeinfested soil placed more than 1.5 cm above or below seeds. Histological observations showed that the hypocotyl and first part of the main root were the most probable sites of infection.
Bacterial Diseases on Witloof Chicory Crops in Europe
Authors: Balestra G. M. , Varvaro L.
Published: May 2008

Distribution of principal phytopathogenic bacterial populations on witloof chicory crops in Europe is reported.

Different symptoms caused by phytopathogenic bacterial populations on different parts of witloof chicory plants are described. The first report of Pseudomonas fluorescens (Trevisan) Migula and occurrence of Erwinia carotovora (Jones, 1901) bacterial populations on witloof chicory cv. Rosso di Chioggia crops in Italy (Latium region), are reported. Risks of disease during different phases of production of this crop and phytosanitary measures to reduce the incidence of disease caused by these pathogens are discussed.
Sensitivity of the ELISA Test to Detect Phytophthora fragariae var. rubi in Raspberry Roots
Authors: Olsson C. H. B. , Hetberg N.
Published: May 2008

A commercial serological, multiwell assay kit was used to assess the detection limits of Phytophthora fragariae var. rubi in raspberry roots. Detection limits in time lapse after inoculation, were assessed after inoculation of root systems of raspberry plants by zoospores of P. fragariae var. rubi. In extracts taken 3‐9 days after inoculation, the pathogen was detected from the fourth day after inoculation. In a test series of simulated P. fragariae var. rubi infection where 0.25, 0.5, 1.0 and 1.5% of infected root tissue respectively, were mixed with healthy tissue (w/w), it was possible to detect the pathogen at 0.25% of simulated infection level. The results obtained show the possibility of an early detection of small amounts of antigen by the ELISA test procedure used. This enhance possibilities for early diagnosis and thereby more effective prevention of Phytophthora diseases in raspberry.
Studies on Pantoea citrea, the Causal Agent of Pink Disease of Pineapple
Authors: Cha J.‐S. , Pujol C. , Ducusin A. R. , Macion E. A. , Hubbard C. H. , Kado C. I.
Published: May 2008

The causal agent of pink disease of pineapple has been identified as Pantoea citrea, a member of the Enterobacteriaceae. Comparative physiological and biochemical analyses demonstrated that P. citrea isolated from diseased pineapple fruit in the Philippines possesses features identical to those of an American Type Culture Collection type strain of P. citrea and not to those of P. ananas, P. herbicola (formerly Erwinia herbicola), and P. stewartii (formerly Erwinia stewartii). P. citrea induces the production of compounds in pineapple which become pink to reddish‐brown upon cooking the fruit, pulp, or juice. This distinct colour is not induced by Escherichia coli, Agrobacterium tumefaciens, Burkholderia gladioli, Pseudomonas fluorescens, Gluconobacter oxydans, Acetobacter aceti, and Acinetobacter calcoaceticus. Like other well characterized bacteria pathogens, such as Pseudomonas syringae pv. phaseolicola, P. citrea elicits the hypersensitive response (HR) in tobacco. By contrast, G. oxydans and A. aceti that have been previously implicated as the causal agents of pink disease, do not elicit HR. Although the nature of the pink colour in pineapple produced by P. citrea has not been elucidated, the locus conferring this activity has been located on its chromosome. The pink colour can be restored in an avirulent, pink colour defective mutant strain, CMC6, by complementation in trans with a specific 3.8 kb genomic DNA fragment of P. citrea. This suggests that P. citrea contains the genetic elements that are required for pink disease.
A Sinapic Derivative as an Induced Defence Compound of Date Palm Against Fusarium oxysporum f.sp. albedinis, the Agent Causing Bayoud Disease
Authors: El Hadrami I. , Ramos T. , El Bellaj M. , El Idrissi‐Tourane A. , Macheix J. J.
Published: May 2008

A non‐constitutive phenolic compound was isolated from date palm (Phoenix dactylifera L.) roots and calli derived from offshoots. It inhibits greatly conidial germination as well as infectious germ tube growth and must be considered as a phytoalexin. Its accumulation occurred when calli turned brown or when roots were in contact with Fusarium oxysporum f.sp. albedinis, the agent causing the date palm vascular fusariosis‘bayoud'. Tentatively, this compound has been identified as sinapoyl‐amide by acid and alkaline hydrolysis, dansylation of amines and polyamines and by ninhydrin treatment. The relationship between this methoxy‐substituted hydroxycinnamic acidamide and biotic and abiotic stress leading to tissue browning or vascular disease resistance is discussed.
Preparation and Regeneration of Mycelial Protoplasts of Alternaria eichhomiae
Authors: Shabana Y. M. , Charudattan R.
Published: May 2008

Preparation and regeneration of mycelial protoplasts from Alternaria eichhorniae were examined. A commercially available muralytic enzyme, Novozym 234, was used for isolation of protoplasts. The mycelial age and the pH of the stabilized buffer affected the formation of protoplasts. The maximum production of protoplasts (3,9 × 108/g fresh weight mycelia) was obtained from 24‐h‐old mycelia digested with Novozym 234 (20 mg/ml) in a stabilized buffer of pH 6.4 and incubated in the dark at 30°C on a rotary shaker (90 r.p.m.) for 6 h. Morphological characteristics of the protoplasts varied and depended on the age of the mycelia used in protoplast production. Moreover, mycelial age had a highly significant influence (P = 0.0001) on the frequency of protoplast regeneration.
Molecular Studies on Orobanche
Authors: Zeid M. , Madkour M. , Koraiem Y. , Nawar A. , Soliman M. , Zaitoun F.
Published: May 2008

The optimization of polymerase chain reaction (PCR) for random amplified polymorphic DNA (RAPD) analysis in Orobanche was investigated and the results were applied to analysis of O. aegyptiaca, O. oxyloba, O. ramosa and three O. crenata collections gathered from different locations in Egypt, Genotypes were compared using 20 random primers. The polymorphisms detected were only between the tested species, while identical banding patterns were generated in collections of the same species.

Genetic similarity among species was estimated on the basis of the percentage of common bands between species and a dendogram was constructed using the unweighted pair grouping method.

Two primers were chosen as specific PCR primers to differentiate between the studied Orobanche species. The results of this study show that RAPDs can be used as a method for clarifying relationships between species of Orobanche.
Transport of Glutamate and Glutamine in the Light Leaf Spot Pathogen Pyrenopeziza brassicae
Authors: Walters D. R. , McPherson A. , Marshall G. , McRoberts N.
Published: May 2008

The kinetics of glutamic acid and glutamine uptake in the light leaf spot fungus, Pyrenopeziza brassicae, are biphasic. At low and high concentrations, glutamic acid and glutamine share a high‐affinity and a low‐affinity carrier, respectively, with Kms of 4.0 and 4.4 μm for uptake of glutamic acid and glutamine, respectively, by the high‐affinity system, and Kms of 580 and 560 μm for uptake of glutamic acid and glutamine by the low‐affinity system. The data suggest that glutamic acid and glutamine are taken up by a different system to that responsible for the uptake of ornithine, arginine, lysine and asparagine, and may represent system IV described in Neurospora crassa for the uptake of acidic amino acids.
Apoplexy of Peach Trees Caused by Pseudomonas viridiflava
Authors: Scortichini M. , Morone C.
Published: May 2008

A sudden apoplexy of young nectarine trees was observed during early autumn 1995 in Piedmont (northern Italy). At collar level, extensive wet necrosis of the tissues beneath the bark was observed. When the infection girdled the trunk, the tree died. LOPAT tests, fluorescence on single‐carbon sources and comparison of whole‐cell protein profiles with type‐strains indicated that the bacterial isolates belong to Pseudomonas viridiflava and P. syringae pv. syringae. In the pathogenicity tests, the first bacterium incited symptoms similar to those observed in the field. This is the first record of P. viridiflava as a pathogen of peach.
Preliminary Studies on Black Spot of Globe Artichoke
Authors: Morzadec J. M. , Hourmant A. , Romancer M. Le , Corre J. , Migliori A.
Published: May 2008

Studies were conducted to determine the cause of an apparently new disorder of globe artichoke (Cynara scotymus L.) characterised by a localised black necrosis in the receptacle of the flower buds. The effects of single and mixed infections by artichoke latent potyvirus (ALV) and broad bean wilt virus – French artichoke (BBWV‐FA) in buds with necrosis of three globe artichoke cultivars were studied. Virus‐free plants developed diseased buds irrespective of whether the plants were 1 or 2 years old, but the presence of ALV and/or BBWV‐FA significantly increased black spot occurrence on 2‐year‐old plants. Virus effects were dependent on cultivar, cv. Capitan being less susceptible to virus infection than cvs Camus de Bretagne and Castel. The head size of the globe artichoke was found to be related to the rate of necrosis, with a higher incidence for terminal buds.

ALV and BBWV‐FA did not cause the disorder but favour its development probably by weakening plants through increased leaf transpiration. The results are discussed in relation to a possible physiological disorder exacerbated by the presence of ALV and/or BBWV‐FA.
Antimycotic Compounds from the Plant Pathogen Rhizoctonia solani and its Antagonist Trichoderma harzianum
Authors: Bertagnolli B. L. , Daly S. , Sinclair J. B.
Published: May 2008

The soilborne rhizosphere‐competent fungal biocontrol agent Trichoderma harzianum isolate Th008 secreted trichodermin (MW = 292) and a small peptide (MW = 876) in culture. These compounds were antagonistic in culture to the mycelial growth of the soilborne fungal pathogen Rhizoctonia solani isolate 2B‐12, which is highly virulent to soybean (Glycine max)seedlings. When 100mg of dried autoclaved mycelial mat of R. solani was added to 200 ml liquid cultures of T. harzianum, the quantity of antimycotic compounds secreted by the latter was 3.5 times greater than that of the antagonist alone. R. solani secreted a coumarin derivative (MW = 313) in liquid culture, which inhibited the mycelial growth of T. harzianum; however, inhibition of the growth of the antagonist required a greater concentration than that for the antimycotic compounds produced by the antagonist against the pathogen. The inclusion of 100 mg of dried autoclaved mycelial mat of T. harzianum in a 200 ml liquid culture of R. solani did not affect the quantity of the antimycotic compound produced by the pathogen.
Effects of Temperature on Germination of Peronospora parasitica Conidia and Infection of Brassica oleracea
Authors: Achar P. N.
Published: May 2008

The effect of temperature on germination of a South African isolate of Peronospora parasitica, and infection of Brassica oleracea was studied. The optimum condition for germination was 20° C at 100% relative humidity. The percentage germination obtained was 80–98% and 70–80% between 15 and 25° C at 100% relative humidity, after a 12 and 6h incubation period, respectively. Optimum temperature for germ tube growth was also 20° C. The temperature range for maximum infection of seedlings of a highly susceptible cabbage cultivar and subsequent disease development in vitro was 15–25° C and 90–100% infection was achieved after 48 h of incubation. At<15°C and 26–30° C infection percentage was decreased to 40–50% and 35–40%, respectively. No disease incidence was recorded at temperatures above 35° C. A scanning electron microscope study of the infection process showed that penetration of cotyledons by germ tubes was mostly via stomata and occasionally directly through the cuticle. Results are discussed in relation to the need for future studies of P. parasitica in South Africa.
Efficacy of Talaromyces flavus Alone or in Combination with other Antagonists in Controlling Verticillium dahliae in Growth Chamber Experiments
Authors: Nagtzaam M. P. M. , Bollen G. J. , Termorshuizen A. J.
Published: May 2008

Talaromyces flat‐US reduced viability of microsclerotia of Verticitlium dahliae on senescent potato stems collected from the field when applied as ascospores in carboxy‐methylcellulose or in talcum powder. Incorporating an alginate wheat‐bran preparation of T. fiavus in soil at a rate of 0.5% (w/w) was followed by a decrease of > 90% of the population of V. dahliae in soil at both 15 and 25 C. Population densities of V. dahliae were negatively correlated (r = ‐0.50; P = 0.001) with those of T. flavus. However, the population of V. dahliae was also reduced in soil with alginate wheat‐bran alone. When incorporated in soil in alginate wheat‐bran and simultaneously coated on seeds in ta.lcum powder. T. flavus reduced colonization of roots and infection of eggplants by K. dahliae. Although to a lesser extent than with the antagonist, alginate wheat‐bran without T. flavus also reduced infection by the pathogen. Treatment with combinations of T. flavus with other biocontrol agents, viz. Bacillus subtilis, Fusarium oxysporum or Gliocladium roseum, containing half of the inoculum of the single application of each antagonist, gave similar control of root colonization and stem infection by V. dahliae as application of the single antagonists. Population densities on the root of each antagonist were not or only slightly affected by the presence of the co‐inoculated antagonist suggesting that the combinations were compatible.
Effect of Saline Environment on Yield and Smut Disease Severity of Different Corn Genotypes (Zea mays L.)
Authors: Souman M. F. , Kostandi S. F.
Published: May 2008

The effects of saline irrigation water on growth, yield, smut index and leaf CI content were investigated under field conditions. The plants were grown in 1994 and 1995 and artificially infected with U. maydis‐ spore‐suspension at V6 and V10 leaf stages. The severity was rated on a 1–9 scale, whenever the symptotns appeared. The results showed that superior growth, greater yield performance, associated with lower smut incidence and leaf Cl contents were generally observed on Taba than its counterparts. Increasing salinity exhibited significant increases in leaf CI and induced marked inhibition on growth, yield and SI data. The salt sensitivity of corn genotypes, as revealed from the comparison of the slope of linear regression equations, was related to 1.00: 1.19;1.42 for cvs Taba, 310 and 320, respectively. The differential yield response with respect to SI data proved that smut susceptibility was inversely related to salt tolerance concept. The data of Cl‐disease interaction showed that smut reactions of highly susceptible and resistant genotypes (cvs 320 and Taba) were hardly monitored by plant Cl content, revealing that disease resistance is genetically controlled. Conversely, the progressive modifications of smut reaction, accompanied by CI accumulation in the moderately susceptible genotype 310 proved that disease resistance was environmentally conditioned by salt stress.
The Role of Calcium in Mediating Smut Disease Severity and Salt Tolerance in Corn under Chloride and Sulphate Salinity
Authors: Kostandi S. F. , Soliman M. F.
Published: May 2008

The effect of sahne irrigation water containing NaCl or Na2SO4 with and without CaSO4 application on the gram yield, smut index and plant nutrient contents of two intermediate smut‐susceptible corn cultivars was investigated in cemented plots containing sandy loam soil. The plants were artificially infected and the disease severity was rated. At the end of silking stage, the leaf C1, Na and Ca contents were detected and Ca/Na ratio was calculated. At harvest, the grain yield of smut‐free and smutted plants was recorded. The results showed that Na2SO4‐treated plants had a greater yield advantage than those exposed to NaCl‐treatments. The inclusion of CaSO4 was beneficial to both salinity types and improved the yield potential. Similarly, smut susceptibility was reduced by 10.8% for the Na2SO4‐stressed plants, compared with 22.7% for NaCl treatment. The comparable reductions in disease severity associated with Ca supply dropped to 33.0 and 17.0%, respectively, indicating the beneficial contribution of a Ca supply on the mediating disease reaction. Although the smut index was markedly decreased as the leaf C1 content increased in Ca‐deficient plants subjected to saline irrigation water without Ca supply, the increase in the Ca/Na ratio in plant tissue, associated with supplemental CaSO4 application to each salinity type, appeared to have an additive effect on smut disease control and salt tolerance.
Application of Hormetic UV‐C for Delayed Ripening and Reduction of Rhizopus Soft Rot in Tomatoes: the Effect of Tomatine on Storage Rot Development
Authors: Stevens C. , Liu J. , Khan V. A. , Lu J. Y. , Wilson C. L. , Igwegbe E. C. K. , Kabwe M. K. , Chalutz E. , Droby S.
Published: May 2008

The application of ultraviolet‐light C (UV‐C, 254 nm) hormesis on tomato fruits to stimulate beneficial responses is a new method of inducing host resistance to Rhizopus soft rot, with maximum protection at 72 h following artificial inoculation with Rhizopus stolonifer and delay fruit ripening. In the tomato‐Rhizopus soft rot pathosystem, UV‐C induced resistance of tomatoes to soft rot was reversed by fluorescent light, and not by storage under dark condition. The present study was aimed at finding a possible fungal toxic mechanism that was involved in the control of Rhizopus soft rot. The development of carotenoids, loss of chlorophyll and ethylene production were significantly retarded during storage after treatment with hormetic doses of UV‐C. The delayed ripening of UV‐C treated fruits was attributed in part to the high level of putrescine and spermine polyamines. In a time‐control study, it was found that the resistance of UV‐C‐treated tomatoes artificially inoculated with R. stolonifer correlated with a high concentration of tomatine which accumulated up to 72 h after UV‐C treatment. However, there was a higher tomatine content in UV‐C‐treated fruits compared to untreated fruits where it was transitory at 96 h after treatment in the time‐course study.
Assessment of Sensitivities to Anilinopyrimidine‐ and Strobilurin‐fungicides in Populations of the Apple Scab Fungus Venturia inaequalis
Authors: Kunz S. , Lutz Bu. , Deising H. , Mendgen K.
Published: May 2008

The sensitivity of Venturia inaequalis populations to the anilinopyrimidine fungicides pyrimethanil and cyprodinil was analysed by microscopic in vivo analysis of conidiophore formation. The sensitivity to the strobilurin kresoxim‐methyl was analysed using an in vitro germination assay and by determination of the diseased leaf area and conidia produced in vivo. Baseline sensitivities were determined with V. inaequalis populations from control orchards that had never been treated with fungicides. Comparison of the baseline sensitivities with sensitivities of populations obtained from orchards that had received 43 anilinopyrimidine treatments over 4 years, or from an orchard with 54 kresoxim‐methyl treatments over 6 years indicated that no resistance to these fungicides has developed at the sites sampled.
Seed Bacterization with Bacillus subtilis AF 1 Increases Phenylalanine Ammonia‐lyase and Reduces the Incidence of Fusarial Wilt in Pigeonpea
Authors: Podile A. R. , Laxmi V. D. V.
Published: May 2008

Cell free culture filtrate of a biocontrol PGPR strain of Bacillus subtilis showed a concentration‐dependent growth and conidiation inhibition of Fusarium udum. the incitant of pigeonpea wilt. In vitro interaction of cell free filtrate of AF 1 induced bulb‐like structures in the hyphae of F. udum. Seed treatment with B. subtilis significantly reduced the incidence of pigeonpea wilt, but not with the cell free culture filtrate of AF 1. Seeds bacterized with B. subtilis AF 1 showed an increase in phenylalanine ammonia‐lyase (PAL) from day 1, while the peroxidase activity increased from day 6. The results are discussed in terms of induction of host plant resistance in biological control of plant pathogens.
Effect of Growth Stage on Resistance to Drechslera teres f. teres in Barley
Authors: Jonsson R. , Bryngelsson T. , Jalli M. , Gustafsson M.
Published: May 2008

Three experiments were conducted to evaluate seedling and adult plant resistance to Drechslera teres f. teres in barley lines with a potential use as resistance sources in barley breeding. Disease resistance of barley seedlings, inoculated in the glasshouse and growth chamber at the one‐ and two‐leaf stages, was significantly (P 0.05) correlated with disease reactions on the fourth and flag leaves of barley plants grown in growth chambers (r= 0.84‐ 0.94) as well as with disease levels recorded on the three uppermost leaves in a field experiment (r= 0.64). Several of the barley lines showed no correlation, demonstrating either improved or decreased disease resistance at later growth stages. Six barley lines (Alexis, Heartland, Kinnan, CI4922, CI9776 and SWl114‐93) had the same ranking in disease resistance to D. teres when damaged (punctured) leaves were inoculated with a drop of spore suspension as when undamaged leaves were spray‐inoculated with a spore suspension.
Acquisition, Retention and Transmission of Faba Bean Necrotic Yellows Virus by Two of its Aphid Vectors, Aphis craccivora (Koch) and Acyrthosiphon pisum (Harris)
Authors: Franz A. , Makkouk K. M. , Vetten H. J.
Published: May 2008

Faba bean necrotic yellows virus (FBNYV) belongs to a new group of plant viruses that have unusually small isometric virions and a multipartite ssDNA genome. It is the causal agent of some virus diseases affecting several food and fodder legumes in west Asia and north Africa. FBNYV is persistently transmitted by various aphid species of which Aphis craccivora appears to be the most significant natural vector. In attempts to obtain a better understanding of factors involved in FBNYV spread under field conditions, the interactions of the virus with A. craccivora and Acyrthosiphon pisum were studied. The two species were efficient vectors and very similar in their minimum acquisition (AAP) and minimum inoculation access feeding periods which ranged from 15 to 30min and 5–15min, respectively. Following an AAP of 72 h and daily serial transfers of individual aphids to single plants, many individuals retained and transmitted the virus throughout their life span (up to 32 days) but at erratic efficiencies. In this persistence experiment A. pisum was a more efficient vector than A. craccivora. For both aphid species no decrease in transmission efficiency was observed, suggesting that nymphs acquired large amounts of FBNYV virions which were not depleted in their hemocoel during the experiment. Based on log‐pro‐bit analysis, median latency period (LPso) values of 108.8h and 105.0h were calculated for FBNYV in A. craccivora and A. pisum, respectively. FBNYV was not lost during moults and was not passed on to the par‐thenogenetic offspring by viruliferous adults. Aphids which acquired FBNYV as adults were strikingly poor vectors as compared to nymphs.
Development and Application of Monoclonal Antibodies Against Xylella fastidiosa, the Causal Bacterium of Pear Leaf Scorch
Authors: Leu H. H. , Leu L. S. , Lin C. P.
Published: May 2008

Ten stable hybridoma cell lines, M As l ‐10, secreting monoclonal antibodies specific to the causal bacterium of pear leaf scorch (PLS), Xylella fastidiosa. were produced. The monoclonal antibodies can detect 3 × 105 PLS‐bacterium cells by indirect enzyme‐linked immunosorbent assay (ELISA). In the antibody titer determination by indirect ELISA, hybridoma‐culture supernatant from clone MA4 had the highest titer of 20480. In the antibody specificity tests, nine of the 10 monoclonal antibodies did not cross‐react with 14 other bacterial strains belonging to nine genera. Only the antibody from hybridoma clone MAI cross‐reacted with Xanthomonas campestris pv. cam‐pestris and X. campestris pv. vesicatoria. In western blot analysis, all the monoclonal antibodies recognized the major 46.9‐kDa polypeptide from all 12 X. fastidiosa strains and a distinct 21.5‐kDa polypeptide only from PLS bacterium. In tissue‐blotting detection, the PLS bacteria were specifically detected in blots of tissue sections from infected pear with the antibodies developed.
Properties of a Cowpea Mild Mottle Virus (CPMMV) Isolate from Eggplant in Jordan and Evidence for Biological and Serological Differences Between CPMMV Isolates from Leguminons and Solanaceous Hosts
Authors: Mansour A. , Al‐Musa A. , Vetten H. J. , Lesemann D.‐E.
Published: May 2008

A virus isolate from an eggplant (Solanum melongena) showing a mild leaf mosaic had slightly curved filamentous particles with a normal length of 653 nm, a capsid protein size of about 32 kDa and a narrow host range restricted largely to the Solanaceae, It was transmitted by the whitefly Bemisia tabaci in a nonpersistent manner but not by the aphid Mvzus persicae. Its particle morphology, vector transmission and strong reactions in immunoelectron microscopic (IEM) decoration tests with antisera to cowpea mild mottle virus (CPMMV) indicated that it is a CPMMV isolate. Particles of the isolate were weakly decorated when antisera to two carlaviruses, carnation latent virus and a distinct but incompletely described carlavirus from Helleborus, were used in I EM but not with 19 antisera to other carlaviruses. When the isolate was compared in host range and serological properties with another CPMMV isolate from tomato in Israel and two legume isolates of CPMMV, the two isolates originating from the solanaceous hosts in Jordan and Israel appeared to be very similar but clearly distinct from the two legume isolates from India and West Africa. In IEM decoration experiments, a legume isolate of CPMMV from Brazil was serologically distantly related to the two other legume isolates but strikingly dissimilar to the Jordanian isolate. Moreover, the isolates from Jordan and Israel differed from the legume isolates by inducing only banded or nonbanded virion aggregates but no brush‐like virion aggregates reported to be characteristic of legume isolates of CPMMV from Africa, Thailand and Brazil. Under the conditions of the present study brush‐like inclusiotis were also found with the Indiati and West African isolates. The incidence of the virus was higher in the autumn than spring growing season. Solanum incanum was identified as a possible perennial reservoir of CPMMV during the summer when the Jordan valley is virtually free from cultivated eggplants
Ice Nucleation Activity of Strains from Pseudomonas syringae Pathovars atrofadens and syringae, Mainly Isolated from Cereals
Authors: Mittelstädt H. , Rudolph K.
Published: May 2008

Ice nucleation activity was determined in 14 strains of Pseudomonas syringae pv. syringae and 16 strains of Pseudomonas syringae pv. atrofadens. mostly isolated from cereals. The majority of the syringae‐strains (85%) possessed ice nucleation activity, with 64% being highly active. In contrast, most of the atrofaciens‐strains (69%) showed no ice nucleation activity, and only 19% were highly active. The results obtained could be confirmed by determining the nucleation frequency in the temperature range from ‐3 to ‐10 C, The data indicate that the capability for ice nucleation might help epiphytic bacteria to colonize leaf surfaces by the release of plant nutrients at mild and short‐term frosts. On the other hand, those Ps. syringae pathovars that can infect and ingress into leaves, are not apparently dependent on ice nucleation activity for pathogenesis.
Complexity of Virus‐like Double‐stranded RN A Elements in a Diseased Isolate of the Dutch Elm Disease Fungus, Ophiostoma novo‐ulmi
Authors: Cole T. E. , Mcller B. M. , Hong Y. , Brasier C. M. , Buck K. W.
Published: May 2008

High resolution polyacrylamide gel electrophoresis has shown that a diseased isolate of the Dutch elm disease fungus, Ophiostoma novo‐ulmi, Logl/3–8d2 (Ld), contains 12 virus‐like double‐stranded (ds) RNA segmetits instead of the 10 segments previously reported. DsRNAs 1 and 3 were each separated into two segtnents, designated dsRNA‐la, dsRNA‐lb, dsRNA‐3a and dsRNA‐3b, respectively. The relative nnobilities of dsRNAs 3a and 3b were reversed when electrophoresed in 4 and 8% gels, indicating that structure as well as size cati contribute to electrophoretic mobility. Analysis of the dsRNA profiles of healthy isolate W2toll (the progenitor of Ld), and healthy single‐conidial isolates derived from Ld, showed that dsRNAs la, lb, 3a and 3b were not the cause of the Ld diseased phenotype. Two single conidial isolates were obtained which contained only dsRNA‐6 which therefore replicates atitonomously. Overall the results indicated that the 12 Ld dsRNAs are comprised of several independent replicons. The single‐stranded form of dsRNA‐10, which potentially has a high level of base‐pairing, was shown to fractionate with the dsRNA.
Differentiation of Pseudomonas avellanae Strains from Greece and Italy by rep‐PCR Genomic Fingerprinting
Authors: Scortichini M. , Dettori M. T. , Marchesi U. , Palombi M. A. , Rossi M. P.
Published: May 2008

In order to point out possible genetic differences, 37 Pseudomonas avellanae strains isolated from northern Greece, northern Italy and two different areas of central Italy, were assessed by means of Repetitive PCR (rep‐PCR) by using Enterobacteriaceae Repetitive Intergenic Consensus (ERIC) primers. After PCR amplifications, the DNA fingerprints revealed three major groups. The strains from northern Greece and those from the two areas of central Italy were similar showing, in common, three major DNA products ranging from approximately 250 to 1100 base pairs. However, strains from northern Greece can be differentiated from strains of central Italy by the presence of two peculiar PCR products of 800 and 350 base pairs. The strains from northern Italy showed very different PCR profiles. When a dendrogram based on cluster analyses was built up, such strains were very different from the strains from the other areas. Isolations carried out at different times did not affect PCR products.
Growth Response of Agrostis palustris to Adventitious Root Infection by Acremonium rutilum and Acremonium alternatum
Authors: Hodges C. F. , Campbell D. A.
Published: May 2008

Acremonium rutilum and Acremonium alternatum are reported as pathogens of the adventitious roots of Agrostis palustris. Both organisms have been isolated from root and leaf tissue of diseased A. palustris on high‐sand‐content golf greens. The presence of the organisms on adventitious roots is usually associated with other potential root pathogens. Three isolates of A. rutilum and one isolate of A. alternatum were evaluated for their ability to infect adventitious roots of A. palustris under high and low temperature regimes and to affect plant growth and symptom expression. Both species of Acremonium infected roots and decreased shoot and root dry weight. The decreases in dry weight were more pronounced under low temperatures than under high temperatures. With the exception of isolate AR‐1 of A. rutilum under the high temperature regime, the decrease in shoot dry weight was disproportionately greater than that of root weight in response to both A. rutilum and A. alternatum. The number of stolons per plant decreased in response to both species of Acremonium under the high and low temperature regimes except for isolate AR‐1 of A. rutilum which increased stolon numbers under the high temperature regime. Foliar symptoms associated with the organisms in the field were not expressed by the root‐inoculated plants. The observations of the study are discussed relative to A. rutilum and A. alternatum as potential emerging pathogens and/or participants in a root disease complex, and relative to the role of high‐sand‐content golf green management practices in the process.
Xanthomonas campestris pv. vesicatoria from Bell Pepper and Tomato in Barbados Undergoes Changes in Race Structure, Virulence and Sensitivity to Chemical Control Agents
Authors: Gore J. P. , O'Garro L. W.
Published: May 2008

Changes in prevalence, aggressiveness and sensitivity to copper and zinc bactericides of Xanthomonas campestris pv. vesicatoria races from bell pepper and tomato in Barbados since 1989‐90 were determined. A total of 16 races were identified and 11 of them, including races P0, P0T1, P0T2, P1T1, P1T2, P2T2, P3T2, P4T1, P4T2, P5T2 and P6T2, were previously unreported on bell pepper and tomato in Barbados. Of the 11 races, P2T2, P4T1, P5T2 and P6T2 were detected on pepper only and T2 only was confined to tomato. Races P1T1 and P6T2, each amounting to 16% of strains from pepper, replaced race P1, which contributed 4%, as the most prevalent strains on this plant genotype. On tomato, races P1T1 and P1T2, in amounts of 36.1 and 21.0%, respectively, of the pathogen collection, replaced race T1, which represented 15.8%, as the predominant strains. Shifts from frequent association of race P1 to races P1T2 and P6T2 and from race T1 to races P1T1 and P1T2 with the greatest amounts of pepper and tomato crop damage, respectively, also occurred. The previously zinc‐sensitive and copper‐resistant pathogen population became resistant to zinc and reverted by 40% to copper sensitivity.
Pathogenicity of Fusarium oxysporum on Different Vitis Rootstocks
Authors: Omer A. D. , Granett J. , Wakeman R. J.
Published: May 2008

The susceptibility of eight Vitis rootstocks to an isolate of Fusarium oxysporum, originally obtained from vineyard‐rotted grape roots, was tested with excised roots in the laboratory and with roots attached to living vines in the field. Excised root assays indicated that the Vitis vinifera rootstock Carignane was most susceptible followed by the V. vinifera‐hybrid rootstock AXR#1, and the non‐V. vinifera rootstocks 110R and St. George, which were the least susceptible of those infected. Inoculations with this isolate of F. oxysporum failed to cause rot on excised roots of the non‐V. vinifera rootstocks 3309C, 420 A, 5C, and Freedom. Only rootstocks Carignane and AXR#1 became infected when non‐excised roots were inoculated. Rootstocks that are most susceptible to grape phylloxera appeared to be highly susceptible to this isolate of F. oxysporum. Additional assays on the infectivity, growth, and sporulation of this isolate at different temperatures indicated that fungal activity increased with temperature within the range of 18‐26°C.
Endophytic presence of Discula quercina on Declining Quercus cerris
Authors: Ragazzi A. , Moricca S. , Capretti P. , Dellavalle I.
Published: May 2008

The presence of Discula quercina on dormant buds and twigs of declining Quercus cerris was studied on two test sites. A number of fungi, including some endophytic ones, were isolated in association with D. quercina as part of the total oak mycoflora: Acremonium spp., Diplodia mutila, Phomopsis quercina, Hypoxylon mediterraneum, Cylindrocarpon sp., Phoma cava and Trichoderma viride plus some less frequent species. The distribution of these fungi did not appear to be related to the altitude of the test sites studied: sea level and 600 m a.s.l., nor to the differing composition of the site vegetation. Discula quercina was isolated both from the twigs (18.02% from woody tissue; 5.82% bark tissue) and from the buds (11.62% embryo; 14.55% bud scales). The results indicate that D. quercina is able to live in symbiosis with its host. Although the colonization of the aerial parts of Q. cerris is possible through infection with wind‐borne inoculum, leaf infection can also occur through overwintering mycelium migrating to the leaves mainly from the buds, but also to a lesser extent from the twigs.
Phylogenetic Analyses of DNA Sequence and RAPD Data Compared in Fusarium oxysporum and Related Species from Maize
Authors: O'Donnell K. , Gherbawy Y. , Schweigkofler W. , Adler A. , Prillinger H.
Published: May 2008

Phylogenetic relationships of several strains within the Fusarium oxysporum species complex and two related species from maize were used to test whether phylogenies inferred from nuclear‐encoded translation elongation factor EF‐1α and mitochondrial small subunit (mtSSU) ribosomal RNA gene sequences are concordant with one derived from random amplified polymorphic DNA (RAPD) characters. Results of a partition‐homogeneity test (PHT) indicated that the EF‐1α and the mtSSU rDNA data‐sets are highly homogeneous (P ≥ 0.99) and could be analysed as a combined data‐set. On the basis of the results of the PHT, the three RAPD partitions were also analysed as a combined data‐set. However, the PHT revealed conflict between the nucleotide and RAPD data (P = 0.001). In addition, results of a t‐test showed that the consistency, retention and rescaled consistency indices obtained with the nucleotide sequence data were significantly higher than those obtained with the RAPD data. The t‐tests of the RAPD data also showed that these indices were significantly higher when using the 15‐mer M13 RAPD primer compared with the two 10‐mer primers. Although homoplasy was much greater for the RAPD data than for the DNA sequence data topologically similar trees were inferred from both data‐sets. However the RAPD data appears to be flawed because it failed to resolve the two major clades of the F. oxysporum complex and trees constructed from the RAPD decamer primers completely failed to resolve the F. oxysporum complex. An unnamed phylogenetically distinct species (Fusarium sp.) intermediate between the F. oxysporum complex and Fusarium redolens was identified in trees inferred from the DNA sequence and RAPD data.
Cinétique ?accumulation et Fongitoxicité des Phytoalexines du Palmier Dattier vis‐à‐vis de Fusarium oxysporum f. sp. albedinis
Authors: Modafar C. El , Tantaoui A. , Boustani E. El
Published: May 2008

Ľinoculation des racines de jeunes plants ?une variété résistante (BSTN) et une variété sensible (JHL) de palmier dattier par une suspension conidienne de Fusarium oxysporum f. sp. albedinis, agent causal du bayoud, s'accompagne par ľinduction de ľaccumulation des phytoalexines, la propyl‐7‐aesculétine et ľhydroxy‐5‐propyl‐7‐aesculétine. La cinétique ?accumulation de ces molécules distingue clairement les deux variétés étudiées. Ainsi, deux phases peuvent être distinguées. Au cours de la première phase de ľinfection (5 à 30 jours), ľaccumulation des phytoalexines est rapide et nettement plus importante chez la variété résistante avec un maximum ?accumulation vers le 15ème jour suivant (2,32 μ mol/g MF). Dans la deuxième phase (30 à 60 jours), la situation s'inverse et la variété sensible accumule des teneurs plus élevées atteignant un maximum (2,96 μ mol/g MF) vers le 40ème jour et qui coincide par ailleurs avec la généralisation de la nécrose racinaire et le flétrissement foliaire. Des biotests réalisés in vitro avec des concentrations équivalentes à celles accumulées in vivo 15 jours après inoculation montrent que celles de la variété résistante (2,36 μ mol/ml) réduisent fortement (de 71 à 86%) la germination des conidies, la croissance des tubes germinatifs, la conidiogénèse et la croissance mycélienne de F. oxysporum f. sp. albedinis. Cependant, les doses accumulées chez la variété sensible (0,55 μ mol/ml), ne manifestent qu'un effet inhibiteur faible de 16 à 27%. Ľensemble de ces résultats met clairement en évidence des réponses différentielles chez la variété résistante BSTN et la variété sensible JHL. Ľimplication des phytoalexines dans la résistance du palmier dattier à la fusariose semble alors être liée à la rapidité et àľintensité de leur accumulation à des doses fongitoxiques dans les premiers stades de ľinfection. Les phytoalexines pourraient ainsi être utilisées comme marqueurs biochimiques de la résistance du palmier dattier au F. oxysporum f. sp. albedinis.
Pretreatment tumor diameter/volume and pelvic lymph node status assessed by magnetic resonance imaging for uterine cervical carcinoma treated with concurrent chemotherapy and radiotherapy
Authors: Kim Hun‐Jung , Kim Woo‐Chul
Published: May 2008

Aim:  The aim is to evaluate the prognostic value of tumor diameter, volume and pelvic lymph node status assessed by magnetic resonance imaging (MRI) in patients with uterine cervical carcinoma patients treated with concurrent chemotherapy and radiotherapy.

Methods:  Ninety‐eight patients diagnosed with stage IB to IIIB cervical carcinoma were entered into the study. Tumor diameter was evaluated in T2‐weighted image. The tumor volume was calculated by the equation (volume = width × length × height × π/6) as an ellipsoid approximation. Univariate and multivariate analyses were performed to identify the prognostic factors for overall survival (OS), disease‐free survival (DFS), pelvic control (PC) and distant metastasis‐free survival (DMFS).

Results:  The 5‐year OS, DFS, PC and DMFS rate were 59.8%, 57.3%, 67.9% and 78.8%, respectively. Using univariate analyses, large MRI tumor diameter (≥4 cm), large tumor volume (≥30 mL), pelvic enlarged pelvic lymph nodes, large clinical diameter (≥4 cm) and International Federation of Gynecology and Obstetrics (FigO) stage showed a statistically significantly unfavorable influence on OS and DFS. In multivariate analyses, large tumor volume affected OS, DFS, PC and DMFS, and enlarged pelvic lymph nodes also affected OS.

Conclusion:  Tumor volume and enlarged pelvic lymph nodes determined by pretreatment MRI examinations were significant prognostic factors for patients with invasive cervical carcinoma treated with concurrent chemotherapy and radiotherapy.
Management and outcomes of adnexal masses during pregnancy: A 6‐year experience
Authors: Balci Osman , Gezginc Kazim , Karatayli Rengin , Acar Ali , Celik Cetin , Colakoglu Mehmet C.
Published: May 2008

Aim:  To demonstrate adnexal masses detected during gestations in a 6‐year period.

Methods:  A retrospective study of pregnancy with adnexal masses requiring surgery over a 6‐year period at the Selcuk University Hospital, a tertiary referral center, between June 2000 and June 2006.

Results:  We detected 36 pregnancies with adnexal masses. The mean age of the patients was 26.6 years (range, 18–42). The mean gestational age at which adnexal masses were detected was 17 weeks (range, 5–36), and the mean gestational age at the time of surgery was 24 weeks (range, 6–41). Postoperative pathology results of the patients were functional ovarian cysts in 14 cases (41.1%), endometrioma in eight cases (23.5%), dermoid cyst in six cases (17.6%), serous cystadenoma in two cases (5.8%), mucinous cystadenoma in one case (2.9%), para‐ovarian cyst in one case (2.9%), and borderline serous tumor in two cases (5.8%). Two patients operated on during the second trimester developed preterm birth risk (5.8%). Miscarriage occurred in only one patient (2.9%).

Conclusion:  In this report, we demonstrate a high rate of surgical intervention of adnexal masses at pregnancy which is secondary to the fact that our center works as a tertiary referral center. Most masses at pregnancies were benign in character and our malignity rate was low. We detected an acceptable complication rate due to surgery in pregnant women.