bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wirkung des pflanzengesundheitsfördernden Rhizobakteriums Agrobacterium radiobacter Stamm G12 gegen den Kartoffelzystennematoden Globodera pallida bei unterschiedlicher Temperatur und Bodenfeuchte
Authors: Hackenberg C. , Sikora R. A. 
Published: May 2008

Abstract Influence of temperature and soil moisture on the biological control of the potato‐cyst nematode Globodera pallida using the plant‐health‐promoting rhizobacterium Agrobacterium radiobacter Treatment of potato tubers with the plant‐health‐promoting rhizobacterium A.radiobacter (G 12) resulted in significant (P 0.05) reductions in G. pallida penetration (25%) in green‐house studies conducted in a non‐sterilized sandy‐loam soil. Significant reductions (P 0.05) in nematode infection were obtained when soil moisture was maintained between 60 and 90% of field capacity. When moisture levels were held at 30% of field capacity, nematode infection was also reduced, but not significantly. A. radiobacter repeatedly reduced nematode root‐infection levels but did not affect the final population density. A. radiobacter reduced the hatch of G. pallida significantly (P 0.01) in vitro up to 70%. The bacterium effectively reduced nematode hatch at both 20 and 25°C.
Pathogenicity of Pseudomonas syringae subsp. savastanoi Mutants Defective in Phytohormone Production
Authors: Iacobellis N. S. , Sisto A. , Surico G. , Evidente A. , DiMaio E. 
Published: May 2008

AbstractThe present study compares the pathogenicity on olive and oleander plants of three wild‐type strains of Pseudomonas syringae subsp. savastanoi (ITM317 and PBa230 from olive and ITM519 from oleander) and three phytohormone‐deficient mutants of ITM519: ITM519‐41 (Iaa+/cytokinins‐), ITM519‐7 (Iaa−/cytokinins+), ITM519‐6 (Iaa−/cytokinins−), Mutants not producing IAA (ITM519‐7and ITM519‐6) only induced necrosis of the inoculated tissues (ITM519‐,6) or swellings on the stems attributed to cytokinin production accompanied by necrosis (ITM519‐7). By contrast, the Iaa+/cytokinins− mutant (ITM519‐41) induced attenuated symptoms on stems and knots similar to those obtained with the parent strain on oleander leaves. Olive strains induced necrosis of oleander leaves and were virulent and avirulent, respectively, on olive and oleander stems.Strain ITM519 and its three mutants were all able to multiply in oleander leaves at similar rates, reaching the same final populations. By contrast, the two olive strains multiply poorly, reaching populations c.102‐fold lower.These results confirm that expression of IAA genes alone is sufficient to initiate the development of knots on oleander while cytokinins are necessary for the full expression of the disease symptoms (determining knot size). The findings also indicate that the plant tissues (stems and leaves) react differently to the various strains of the bacterium and, furthermore, suggest that, besides phytohormones, other pathogenetic factors could be involved in this host‐pathogen interaction. The necrotic reaction of oleander leaves heavily inoculated with olive strains was interpreted as a possible form of hypersensitivity reaction.
Induction of a Thionin, the Jasmonate‐Induced 6 kDa Protein of Barley by 2,6‐Dechloroisonicotinic acid
Authors: Wasternack C. , Atzorn R. , Jarosch B. , Kogel K. H. 
Published: May 2008

AbstractThe systemic acquired resistance (SAR) was studied in barley to find out specific molecular markers for this type of resistance. Such markers may serve as diagnostic tools to indicate the defense‐status of a plant and, additionally, may be used to identify new resistance‐inducing compounds in broad screening experiments. Upon treatment of barley leaves with the resistance‐inducing compound 2,6‐dichloroisomicotinic acid (INA) we found, in addition to a yet unidentified basic protein of 45 kDa (designated BIR‐1) induction of a specific 6kDa polypeptide. Using Northern‐and Western blot analysis this small polypeptide was identified as JIP‐6, a known member of the jasmonate‐induced protein (JIP)‐family of barley that was previously demonstrated to be a leaf thionin (ANDRESEN et al. 1992).
Signal Molecules Inducing Systemic Resistance and Susceptibility in Barley Seedlings
Authors: Hiramoto T. , Tobimatsu R. , Abe N. , Shiraishi T. , Oku H. , Yamada T. , Ichinose Y. 
Published: May 2008

AbstractExudate collected from the cut end of barley seedlings exhibited both activities that induced systemic resistance and susceptibility against Erysiphe graminis f. sp. hordei race Hh4 depending on the time after pruning. Exudates collected between 3–6 h after pruning showed maximum activity that induced systemic resistance, whereas those during 9–12 h conversely induced susceptibility in barley seedlings. The accumulation of antifungal substances in barley leaves correlates to the timing, of induced resistance. The antifuntingal substances were watersoluble and severely affected the infection of E. graminis f. sp. hordei.
Effect of Ustilago maydis (DC) Corda and its Toxin on Some Maize Cultivars
Authors: Alaa M. Abou‐Zeld 
Published: May 2008

AbstractThe pathogenic effects of Ustilago maydis (DC) Corda to five maize cultivars and four other plants were studied. It was found that none of the maize cultivars tested was resistant to the common smut disease whereas cultivars Balady was slightly susceptible. Only Sorghum rulgare from the other tested plants showed moderate susceptibility to the disease. With respect to gall formation only cultivars Giza 2 and single cross hybrid 10 formed galls after 2 weeks. The pure toxic material (Ustizeain) from Ustilago maydis was obtained, it caused chlorosis and necrosis on detached maize leaves, but it had no effect on growth of some fungi tested. Sporidia treatment showed also chlorosis on detached maize leaves.
Untersuchungen zur Lagerung und Aggressivität von Peronospora parasitica und Ergebnisse im Hinblick auf die Sortenanfälligkeit des Erregers an Winterraps
Authors: Klodt‐Bussmann E. , Paul V. H. 
Published: May 2008

Abstract Results on preservation and aggressiveness of Peronospora parasitica and results with regard to the disease reistance of the paAogen on winter oilseed rape Laboratory‐tests showed, that a long‐time preservation of Peronospora parasitica‐coiaia in a freezer at ‐ 21° C for a period of 1 year was possible using glycerine, poiyethylenglycol (PEG) 400 or PEG 1000 as cryoprotective agents. Glycerine in a concentration of 20% was ascertained as most suitable additive with germination‐rates of 21% after a storage of 1 year.Using a cotyledon‐test a simple and non‐time‐consuming method could be established to find out differences in winter oilseed rape varieties and differences in the aggressiveness of different P. parasitica isolates. Of 32 winter‐oilseed rape varieties Synra was the least susceptible variety to the pathogen; Diadem, Doublol and Accord were the most susceptible varieties. The research on aggressiveness of different isolates gave evidence, that only the British isolate P003. differed in aggressiveness from the other isolates.
Behaviour of the Phenolic Compounds on Capsicum annuum Leaves Infected with Phytophthora capsici
Authors: Lizzi Yves , Roggero Jean Pierre , Coulomb Philippe Jean 
Published: May 2008

AbstractIn Capsicum annuum leaves, some phenolic compounds, such as chlorogenic acid and various apigenin or luteolin glycosides, can be separated by HPLC technique. During infection with Phytophthora capsici (the agent of pepper mildew), the concentrations of these compounds decreased. A fungal glucosidasic activity may be implicated, producing apigenin aglycon in the necrotic areas. Some of the phenolic compounds were only present in intercellular spaces, where their concentration increasedduring fungal infection, mostly in the resistant pepper cultivar.The involvement of phenolics in C. annuum resistance is discussed in relation to oxidative metabolism.
Effect of Leaf Rust on Yield Components of Winter Rye Hybrids and Assessment of Quantitative Resistance
Authors: Miedaner T. , Sperling Ursel 
Published: May 2008

AbstractLeaf rust (Puccinia recondita f. sp. secalis) is common in all winter rye growing areas, but little is known about its effect on yield in hybrid rye. Ten single crosses without any hypersensitive response to leaf rust were grown at three environments (Hohenheim, 1991; Halle, 1991; Hohenheim, 1992) in an inoculated and a non‐inoculated, fungicide protected, treatment block. Resistance traits were mean leaf rust ratings of the upper three leaves (F‐2, F‐1, F) assessed with 10 arbitrarily, chosen tillers per plot at four assessment dates, selected leaf rust rating on two leaves at one assessment date, and area under disease progress curve (AUDPC). Additionally, kernel number per head, grain weight per head and thousand kernel weight were assessed on the individual tillers in three environments and plot yield and thousand kernel weight of the thresheld plot samples in two environments. Correlations among AUDPC values and mean leaf rust ratings on the respective leaves and selected leafrust rating were high (r∼0.9, P = 0.01). Resistance among the upper three leaves was closely correlated (r∼0.9, P = 0.01) for AUDPC value and mean leaf rust rating. Leaf rust epidemics significantly reduced grain weight per head, plot yield and thousand kernel weight in three environments; kernel number per head was not significantly affected. Thousand kernel weight was reduced on average by 14% ranging from 11 to 27% among single crosses. Significant genotypic variation was observed for the affected yield components at Hohenheim 1991 and 1992. Genotype‐year interaction variance was large in the combined analysis for yield components. Quantitative resistance can be assessed by visual rating of maximal two leaves at one optimal assessment date. Relative, thousand kernel weight from thresheld plot samples can be used additionally as resistance trait when disease severity is high enough during kernel filling.
Restriction Fragment Length Polymorphism Analysis of the Mitochondrial DNA of Fusarium oxysporum f. sp. ciceris
Authors: Pérez‐Artés E. , Roncero M. I. G. , Jiménez‐Díaz R. M. 
Published: May 2008

AbstractSeven isolates of Fusarium oxysporum f. sp. ciceris, representing pathogenic races 1, 2, 3, and 4 from India and 0, 5, and 6 from Spain, were assayed for restriction fragment length polymorphisms (RFLPs) in the mitochondrial DNA,(mt DNA). The mt DNA fraction of total fungal DNA was purified and digested with the restriction endonucleases Bam HI, Bgl II, Eco RI. Kpn I, Sac I, Sal I, Sma I, and Xho I. The mt DNA is a circular molecule of 40.5 kb. No RFLP in the mt DNA was detected among the seven races of F. o. ciceris. The identical restriction patterns of mt DNA indicates an extensive conservation in the gene composition of mt DNA without sequence variation, and suggests that mt DNA of F. o. ciceris may not be responsible for pathogenic diversity. The restriction map of mt DNA from the race 6 isolate Fo 8272 was constructed by digestion of the mt DNA with five restriction enzymes: Eco RI, Kpn I, Sac I, Sal I, and Xho I, either singly or in selected pairs.
Fungi Associated with Foot Rots on Winter Wheat in Northwest Italy
Authors: Rossi V. , Cervi C. , Chiusa G. , Languasco L. 
Published: May 2008

AbstractIn a 3‐year survey on bread and durum wheat grown in Northwest Italy, brown root rot was the most important disease of the basal part of culm. Year, wheat‐growing area, cultivar and their interactions significantly influenced brown root rot incidence. The most important fungal species isolated from lower stems with browning were Microdochium nivale, Drechslera sorokiniana, Fusarium avenaceum, F. graminearum, and F. culmoniliforme, and Pythium spp. were frequently isolated. F., crookwellense was also isolated. Sharp eyespot was a frequent disease; take‐all and eyespot occurred only occasionally.
Characterization of Pyrenophora Isolates Associated with Spot and Net Type Lesions on Barley in South Africa
Authors: Louw J. P. J. , Victor D. , Crous P. W. , Holz G. , Janse B. J. H. 
Published: May 2008

AbstractSingle‐spored isolates of Pyrenophora associated with spot and net type net blotch of barley were compared using total DNA banding patterns, morphological and cultural characteristics, symptomatology and mating studies. Isolates of spot and net type net blotch were found to vary regarding conidium length and cultural growth rate. Mating studies among and between ascospore, spot and net type isolates proved unsuccessful under the conditions studied. Total DNA polymorphisms of the net spot and ascospore isolates digested with the restriction enzymes HpaII and HaeIII showed that the isolates have similar banding patterns. Random amplified polymorphic DNA (RAPD) showed that the banding patterns of the spot and net type isolates were again similar but were distinct from outgroups such as P. semeniperda and P. triticirepentis. The homology in DNA banding patterns of local isolates indicated that the difference in conidium length is insufficient to separate them as two species. It is concluded that spot and net type isolates occurring in South Africa belong to P. teres. Therefore spot type lesions are caused by P. teres f. sp. maculata and not by P. japonica as reported previously.
Difference Between Xanthomonas campestris pv. phlei and X.c pv. graminis Revealed by Genomic Fingerprinting and Restriction Fragment Length Polymorphism Patterns
Authors: Wang H. M. , Sletten A. , Klemsdal S. S. 
Published: May 2008

AbstractGenomic DNA was prepared from 16 strains of Xanthomonas campestris pv. graminis and Xanthomonas campestris pv. phlei isolated from six species of forage grasses in four countries. The two pathovars could be distinguished clearly by genomic fingerprints generated by EcoRI, BamHI or HindIII digestion. DNA profiles produced by HindIII digestion could differentiate not only between the two pathoars but also among strains within the same pahtovar from different countries. A 1.6 kb EcoRI fragment was cloned from genomic DNA of strain LMG726 and used to detect restriction fragment‐length polymorphism among the same strains. EcoRI and BamHI polymorphisms were seen between the two pathovars probed with this 1.6 kb EcoRI fragment (p726EI probe). These polymorphisms appeared to be highly conserved and unique for each pathovar, consistent with previous grouping of the strains based on other criteria.
Ranking Block Mixture Patterns of Differing Host Genotype Unit Area by the Use of Long‐Term Rates of Disease Increase
Authors: Goleniewski G. 
Published: May 2008

AbstractA spatial component is added to a model for the spread of a disease composed of m pathotypes in an n cultivar mixture and is employed to simulate disease progress in a series of fixed block mixture geometries of varying host genotype unit area. The spatial model contains only one pathotype for simplicity. It is demonstrated numerically that it possesses a rate of disease increase p in common with spore pool mixture models which do not posses explicit spatial structure. This parameter is used to rank block mixture patterns of differing host genotype unit area. The variation in rate of disease increase with autodeposition is shown graphically for the chosen set of block geometries.
Infection of Grapevine Roots by Agrobacterium vitis and Meloidogyne hapla
Authors: Süle S. , Lehoczky J. , Jenser G. , Nagy P. , Burr T. J. 
Published: May 2008

AbstractCombined inoculation of grapevine roots with Meloidogyne hapla and Agrobacterium vitis at the level of 102–3 bacteria/g of soil resulted in root infestation by A. vitis. When inoculation of M. hapla and A vitis was applied, most of the feeder roots were dead and at points of secondary root branching, dark lesions could be observed. Along the secondary living roots, typical nematode induced galls could be seen. In many cases the infection stopped growth ofthe main or secondary roots. Plants inoculated with A. vitis alone did not show any galls or swellings on roots and its infection did not stop root growth. However in the M. hapla only treatment, small swellings or elongated galls were readily apparent on secondary roots. These galls were always exempt of A. vitis. Xylem sap, collected in spring 2 years after inoculation of A. vitis+M. hapla yielded many A. vitis cells demonstrating that the bacteria became systemic in plant vessels.
Increase of Complex Pathotypes of Erysiphe graminis f. sp. hordei in Two‐Component Mixtures of Spring Barley Cultivars
Authors: Huang R. , Kranz J. , Welz H. G. 
Published: May 2008

AbstractPathotypes of Erysiphe graminis f. sp. hordei were monitored at fortnightly intervals in pure stands of cultivars Golf with Laevigatum resistance [gene Ml(La)], Steina with Arabische resistance (Mla 12) and Harry with Monte Cristo resistance (Mla9), as well as in two two‐component mixtures [Golf + Steina (G + S) and Golf + Harry (G + H)] during the course of mildew epidemics in replicated field trials. The number of colonies per main tiller was also recorded. Virulence complexity (i.e. the average number of virulence genes per isolate with respect to the two matching resistance genes of the mixed cultivars) was always higher in mixtures than in pure stands. Linear regression of complexity on the number of elapsed mildew generations (based on actual temperature data) gave significant b‐values (slopes) of 0.039, 0.034, 0.022 and 0.018 on Golf in G + S, Steina in G + S, Golf in G + H and Harry in G + H, respectively. In pure stands, there, was no significant complexity increase on any cultivar. The fact that b‐values were higher on either component in the G + S than in the G + H mixture indicates stronger selection for the complex, i.e. two‐virulence, pathotypes in G + S. Complex pathotypes had a higher relative fitness than simple (one‐virulence) pathotypes in both mixtures but not in the pure stands. The absolute frequencies of complex pathotypes as measured by the area under the colony frequency curve (AUCFC) were higher on all cultivars in mixtures than in pure stands, except on Steina.
Comparison of Techniques for the Production of Sclerotinia trifoliorum Ascospores in the Laboratory for Forage Legumes Resistance Tests
Authors: Delclos B. , Raynal G. 
Published: May 2008

AbstractThis study aimed to improve the production, under controlled conditions, of Sclerotinia trifoliorum ascospores to be used for selection tests on forage legumes. Sclerotia of this fungus, produced in the laboratory, were buried 1–2 cm deep in permanently soaked vermiculite, at T = 15°C, 12/24 h of fluorescent light, air moisture >80% in order to differentiate apothecia. The ascospores were harvested by aspiration and collected on a membrane filter. Various types of apparatus containing sclerotia have been tested for their ability to maintain live apothecia and for the facility of spore catching. The aspiration method has been found to be much more efficient than the previous method of cutting off apothecia. Moreover, it was observed that using this harvesting technique the best apparatus presented small and independent compartments (truncated plastic bottles). The ascospores can be stored, on the membrane filter at 5°C and in dry conditions in order to preserve their germinating abilityfor, a period of 3 months at least. This spore harvesting method permits avaibility of large quantities of a cheap inoculum for S. trifoliorum resistance test on forage legumes all year round.
Surface Ultrastructural Studies on Ingress and Establishment of Pseudomonas syringae pv. mori on Mulberry Leaves
Authors: Gupta V. P. , Tewari S. K. , Datta R. K. 
Published: May 2008

Abstract P. syringae pv. mori multiplied on leaf surface and colonized particularly on the cystoliths and in the grooves of veins. The masses of bacteria were associated with necrotic spots, which appeared 9 days after inoculation. The studies also revealed that the bacterium invaded leaf tissues through cystoliths. However, it did not enter through stomata and trichomes which had commonly been observed in most of the plant pathogenic bacteria.
Influence of pH on Suppression of Fusarium Wilt of Carnation by Pseudomonas fluorescens WCS417r
Authors: Duuff B. J. , Erkelens A. , Bakker P. A. H. M. , Schippers B. 
Published: May 2008

AbstractThe influence of the nutrient solution pH on suppression of fusarium wilt by Pseudomonas flurescens WCS417r in carnation grown in rockwool was investigated.Experiments were conducted with carnation cultivars Lena and Pallas, susceptible and moderately resistant to fusarium wilt, respectively. WCS417r significantly reduced fusarium wilt in the susceptible cv. Lena, that was root‐inoculated with Fusarium oxysporum f.sp. dianthi (Fod), at pH 7.5, but not at pH 6.5 and 5.5 This corresponded with a higher in vitro siderophore production and antagonism of Fod by WCS417r at pH 7.5 than at pH 6.5 and 5.5. Fusarium wilt in the moderately resistant cv. Pallas, however, was also significantly reduced by treatment with WCS417r at pH 5.5 This corresponded with the low influence of pH on induced resistance by WCS417r in plants of cv. Pallas that were stem‐inoculated with Fod.The results indicate that the influence of pH on control of fusarium wilt of carnation by Pseudomonas fluorescens WCS417r differs between carnation cultivars that differ in their level of resistance against fusarium wilt. In susceptible cv. Lena, fusarium wilt is suppressed by antagonism by WCS417r, that is most effective at pH 7.5. In the moderately resistant cv. Pallas, fusarium wilt is suppressed by both antagonism and induced resistance by WCS417r. The latter is also effective at lower pH.
Characterization of an Isolate of Tobacco Necrosis Virus From Zucchini
Authors: Roggero P. , Lisa V. 
Published: May 2008

AbstractTobacco necrosis virus (TNV) was isolated from glasshouse zucchini plants in Liguria, northern Italy, showing yellow spots on young leaves and necrotic symptoms on older leaves, petioles and stems. No other viruses were present in these plants. Experimentally, the virus systemically infected zucchini seedlings grown in naturally infected soil but only local infections were induced when leaves and roots were mechanically inoculated. The virus was identified as serotype D, devoid of satellite particles. This appears to be the first report of TNV in zucchini. Three ELISA procedures for field detection of TNV using polyclonal antibodies for serotype D were compared. Antibodies were conjugated with I) alkaline phosphatase (AP‐AB);2) N‐Hydroxy‐succinimid obiotin (BNHS‐Ab); 3) N‐biotinyl‐6‐aminocaproic hydrazide (BACH‐Ab). The procedure using BNHS‐Ab detected the lowest concentration of the homologous virus, followed by BACH‐Ab and AP‐Ab. Only with biotinylated antibodies. TNV serotype A was also detected.