bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensitivity of the ELISA Test to Detect Phytophthora fragariae var. rubi in Raspberry Roots
Authors: Olsson C. H. B. , Hetberg N. 
Published: May 2008

AbstractA 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

AbstractThe 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

AbstractA 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

AbstractPreparation 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

AbstractThe 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

AbstractThe 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

AbstractA 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

AbstractStudies 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

AbstractThe 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

AbstractThe 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

Abstract 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractCell 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

AbstractThree 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

AbstractFaba 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

AbstractTen 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.