bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors Affecting Germination and the Mode of Germination of Zygospores of Choanephora cucurbitarum
Authors: Yu M. Q. , Ko W. H. 
Published: May 2008

AbstractTreatment of zygospores of Choanephora cucurbitarum with KMnO4, NaClO or H2O2 effectively activated the spores and induced their germination. The optimum concentration of KMnO4 for activation of zygospores was 0.25 to 0.5%. Zygospores were not able to germinate in darkness even after activation by KMnO4. When zygospores from 40 to 50‐day‐old cultures were treated with 0.5% KMnO4 solution for 60 min before incubation on water agar at 24% under light, about 50% germinated in 10 days. KMnO4 treatment killed more than 99% of residual mycelial fragments, sporangiospores and sporangiola in the zygospore suspension. During germination disappearance of oil droplets in zygospores occurred prior to the cracking on zygospore wall. Both sporangial germination and mycelial germination were found. Moreover, sporangiole germination was observed for the first time.
Pseudomonas syringae pv. syringae Causal Agent of Disease on Floral Buds of Actinidia deliciosa (A. Chev) Liang et Ferguson in Italy
Authors: Balestra G. M. , Varvaro L. 
Published: May 2008

Abstract Pseudomonas syringae pv. syringae as causal agent of floral buds necrosis, has been isolated from kiwifruit plants cv. Hayward in Italy. The pathogen has been identified on the basis of morphological, biochemical and physiological features and also on the basis of pathogenicity. Symptoms, similar to those caused by Pseudomonas viridiflava—browning and darkening on floral buds, have been observed on kiwifruit plants in a wide area in the North of Latium region (central Italy), in Viterbo province.
Susceptibility and Resistance of Citrus Genotypes to Alternaria alternata pv. citri
Authors: Solel Z. , Kimchi M. 
Published: May 2008

AbstractA survey of citrus cultivars in Israel in orchards where Alternaria brown spot was common on Minneola tangelos (mandarin × grapefruit), revealed the occurrence of the disease as typical foliar and fruit lesions on Dancy and Ellendale (mandarins), on Murcott tangor (mandarin × sweet orange), on Nova and Idith (mandarin hybrids), on Calamondin, and on Sunrise and Redblush (grapefruit). Isolates of Alternaria alternata from each of these hosts were proven to be pathogenic to Minneola tangelo.The host range of A. alternata pv. citri from Israel was assayed by inoculating leaves of diverse citrus genotypes. Several mandarins and their hybrids (Dancy, Kara, King, Wilking, Satsuma, Minneola, Orlando, Mikhal, Idith, Nova, Page, Murcott), grapefruit (Marsh seedless), grapefruit × pummelo (Oroblanco), sweet orange (Shamouti, Valencia, Washington navel) Calamondin, and Volkamer citrus were susceptible. Several mandarins and their hybrids (Clementine, Avana, Yafit, Ortanique), Cleopatra, one sweet orange cultivar (Newhall), pummelo (Chandler), lemon (Eureka), Rough lemon, Rangpur lime, sweet lime, citron, limequat, sour orange, Troyer citrange and Alemow were resistant.
Flow Cytometric Analysis of Conidia of Fungi Isolated from Soybean Vascular Tissue
Authors: Gourmet C. , Gray L. E. , Rayburn A. L. 
Published: May 2008

AbstractFlow cytometry was used to characterize isolates of Phialophora gregata using the fluorescence intensity of propidium iodide‐stained conidia. The isolates differed in their mean fluorescence intensity, ranging from 100.0 to 129.7 arbitrary units (AU). When the number of fluorescent events was plotted against intensity of fluorescence, a single peak was observed. Fluorescent patterns of Acremonium isolates from soybean vascular tissue were compared with those of P. gregata. Their mean fluorescence intensity ranged from 76.4 to 88.0 AU. With some of these isolates, multiple peak histograms were observed, corresponding to multiple spore sizes as well as single and double nucleated conidia. Using flow cytometry, we were able to distinguish P. gregata isolates from those of Acremonium, based on mean fluorescence intensity and/or the presence of multiple peaks. Flow cytometric analysis of propidium‐iodide stained conidia of Phialophora isolates should prove to be useful for determining the relative DNA content of different isolates collected from different geographic areas.
Variation Within and Between Phytophthora Species from Rubber and Citrus Trees in China, Determined by Polymerase Chain Reaction Using RAPDs
Authors: Zheng F. C. , Ward E. 
Published: May 2008

AbstractVariation among 39 isolates of Phytophthora of six morphological species (P. citrophthora. P. parasitka, P. capsici, P. palmivora and P. meadii. from rubber and citrus trees, and P. colocasiae from taro) was studied using random amplified polymorphic DNA (RAPD) analysis. Ten randomly‐chosen 10‐mer primers were used. Generally, the banding patterns were similar within species and different between species, but no one primer was able to distinguish all six species from one another. Cluster analysis on pooled data from all the primers gave six groups of isolates corresponding to the six morphological species. The group corresponding to P. citrophthora was divided further into subgroups that were related to host species and geographical location. This work confirmed the existing morphological classification of Phytophthora isolates from rubber and citrus trees in tropical China and showed the validity of using RAPDs to study the taxonomy of Phytophthora.
Characterization of DNA Sequences Cloned From Resting Spores of Plasmodiophora brassicae
Authors: Ito S. , Nakamura T. , Matsumoto T. , Maehara T. , Tanaka S. , Kameya‐Iwaki M. , Kishi F. 
Published: May 2008

AbstractForty‐four clones containing P. brassicae genomic DNA fragments were isolated from a partial genomic library (pUC118) of the fungus. Eleven DNA fragments were arbitrarily selected from them and partially sequenced. Southern blot analysis was performed using the 11 DNA fragments as probes to estimate the copy number of these DNA fragments in the P. brassicae genome and to see if they hybridized also to genomic DNA of host plant (Chinese cabbage). Five of those (Nos 24, 48, 54, 57, and 108) were of single‐copy and hybridized only to DNA bands of P. brassicae. Two fragments (Nos 4 and 15) were found to contain repetitive sequence of/“, brassicae. Three fragments (Nos 69,73, and 82) hybridized to DNA bands of both host and P. brassicae while the size and the number of the bands were different between host and P. brassicae. Data base searches revealed that one of the single‐copy fragments (No. 48) had high homology with yeast RNA polymerase II gene.
Effect of Leaf Age and Nodal Position on Receptivity of Rice Leaves to Infection by Pyricularia grisea
Authors: Yang Y. , Wilson L. T. , Makela M. E. , Marchetti M. A. , Krausz J. P. 
Published: May 2008

AbstractThe effect of leaf age and nodal position on leaf receptivity to rice blast, caused by Pyricularia grisea, was studied by inoculating potted Rosemont plants with blast pathogen race IC‐17, isolate 92T107. at different growth stages. Regressioti equations were used to describe the effect ofleaf age (degree days > 10 C) and nodal position on lesion density, the relative frequency of lesion appearance, and the lesion area distribtition. The number of sporulating lesions per cm2 of inoculated leaf area was highest for leaves inoculated early in their development and progressively lower for leaves inoculated later in their development. The average lesion density for less than 1‐day‐old leaves at nodal position 6 was about four times the density for 10‐day‐old leaves of the same nodal position. Lesion density was similar for leaves of less than 1‐day‐old from the 4th to the 7th nodal position, but dropped sharply from the 7th to the 11 th nodal position. The flag leaf was the least susceptible of all nodal positions. The average lesion density for young leaves of about 1‐day‐old at nodal position 6 was about 27 times the density for young flag leaves of the same age. The incubation period increased with leaf age. but was not obviously affected by leaf nodal position. Lesion area increased linearly with time, but was not affected by leaf age and nodal position. The results are of use for epidemiological investigations which rely on detailed quantitative leaf susceptibility data for accurate blast forecasts.
Variation of Rice Tungro Viruses: Further Evidence of Two Rice Tungro Bacilliform Virus Strains and Possibly Several Rice Tungro Spherical Virus Variants
Authors: Druka A. , Hull R. 
Published: May 2008

AbstractRice tungro disease is caused by two viruses: rice tungro spherical virus (RTSV) and rice tungro bacilhform virus (RTBV). Our results obtained using polymerase chain reaction (for RTBV) and western blot analysis (for RTSV) to study the epidemiology of tungro supported earlier studies that two RTBV strains. South East Asian and Indian, can be differentiated and also better defined the geographic distribution of these two strains.Data on RTSV variation were not so conclusive and consistent as those on RTBV because of the high degree of microvariation of RNA genomes. Our approach for differentiation of RTSV led to three variants being identified, the geographic distribution of which does not correlate with that found for strains of RTBV.
Scanning Electron Microscopical Observation and X‐ray Microanalysis of Erysiphe pisi DC on Infected Leaves of Pea (Pisum sativum L)
Authors: Sugawajra K. , Singh U. P. , Kobavashi K. , Ogoshi A. 
Published: May 2008

AbstractObservations on scanning electron microscope (SEM) and low vacuum scanning electron microscope (LVSEM) of Erysiphe pisi in infected leaves of pea (Pisum sativum). are reported together with data from X‐ray micro‐analysis. Morphology of ungerminated and germinated conidia was observed and LVSEM revealed halo formation around the penetration peg of the pathogen. X‐ray microanalysis of the composition of halo showed the accumulation of Si and P. Presence of S. Mg, Cl, K and Ca was also discerned. Deposition of Si in the halo and profuse growth of the pathogen indicate that Si deposition is not an essential signal for inducing resistance in the host. LVSEM appears to be a suitable and rapid method to study the morphology as well as halo formation in E. pisi. X‐ray microanalysis and LVSEM studies of E. pisi are reported for the first time.
A Microscopic Characterization of the Infection of Green and Red Pepper Fruits by an Isolate of Colletotrichum gloeosporioides
Authors: OH Boung‐JUN , KIM KI Deok , Kim Young Soon 
Published: May 2008

Abstract Colletotrichum gloeosporioides is a common pathogenic fungus in many plants. To investigate the specificity of the isolate C. gloeosporioides to green fruits, fungal behaviours and anthracnose development on green and red pepper fruits were compared using light and stereo microscopic techniques. When the isolate of C. gloeosporioides was inoculated on both green and red fruits, conidial germination, appressoria, and infection hyphae were observed on both fruits within 24 h after inoculation. The fungal invasion and colonization continued to the epidermal cells of green fruits, but not to those of red ones. Initial anthracnose symptoms were detected only on green fruits at 2 days after inoculation resulting in typical sunken necrosis within 5 days after inoculation. Thus the specificity of the isolate to green fruits may be due to successful invasion and colonization of the infection hyphae from appressoria into the epidermal cells through epicuticular layers of green pepper fnats, but not on red ones.
Development of Cloned DNA Probes for Phytoplasma Associated with Loofah Witches’ Broom
Authors: Kuan C. P. , Su H. J. 
Published: May 2008

AbstractDNA was isolated from periwinkle (Catharanihus roseus) infected with a phytoplasma that originated in loofah witches’ broom affected by loofah. Cloned DNA inserts from six LfWB‐phytoplasma specific recombinant plasmids were not only labelled with digoxigenin, but also used as probes. Probes hybridized with DNA derived from LfWB‐phytoplasma affected periwinkle and loofah, but not with DNA from healthy plants or plants infected with phytoplasmas associated with elm yellows, red bird cactus, peanut witches’ broom, paulownia witches’ broom, Ipomoea obscura witches’ broom, aster yellows (two isolates), and sweet potato witches’ broom obtained with DNA from different phytoplasmas experimentally maintained in periwinkle. The probes could detect LfWB‐phytoplasma DNA with as little as 16 ng and 32 ng of DNA from periwinkle and loofah, respectively. The method proposed herein provides a means for specifically detecting and identifying of loofah witches’ broom phytoplasma, as well as confirming the notion that this phytoplasma represents a distinct strain cluster,
Resistance Against Pepper Severe Mosaic Potyvirus in Transgenic Tobacco Plants
Authors: Rabinowicz P. D. , Bravo‐Almonacid F. F. , Lampasona S. , Rodriguez F. , Gracia O. , Mentaberry A. N. 
Published: May 2008

AbstractThe coat protein gene of the pepper severe mosaic poty‐virus was introduced into tobacco plants. Several transgenic lines were assayed for virus resistance under greenhouse conditions. Line 232, showing higher levels of resistance than other transgenic plants, was studied in further detail. Upon challenge with PepSMV, R2 descendants from this line were monitored for virus accumulation for a period of 45 days. Virus titre was lower in plants of the line 232 than in control plants throughout the experiment. At 14 days post‐inoculation the transgenic plant line reached the maximum virus accumulation measured by ELISA. Those plants also showed a 1 week delay of virus accumulation by comparison with control plants. After reaching the peak at 14 days post‐inoculation the virus titre in line 232 decreased with respect to control plants, until the end of the experiment. These results are compatible with the presence of an RNA‐mediated resistance mechanism.
Calanthe Mild Mosaic Virus, a New Potyvirus Causing a Mild Mosaic Disease of Calanthe Orchid in Japan
Authors: Gara I. W. , Kondo H. , Maeda T. , Inouye N. , Tamada T. 
Published: May 2008

AbstractCalanthe mild mosaic potyvirus (CalMMV), a previously undescribed virus found in several locations in Japan, causes mild leaf mosaic and flower colour breaking of Calanthe plants. CalMMV was mechanically transmitted only to Calanthe sp., Phalaenopsis sp. and Tetragonia expansa of 50 plant species tested and was transmitted by the aphid Myzus persicae in a nonpersistent manner. The virus has flexuotis particles about 764 nm long and induced the formation of intracellular cytoplasmic cylindrical inclusions. The virus particles contain a single poly‐peptide of 32.0 kDa and a single RNA of mol. weight 3.1 × 106. As determined by immuno‐electron microscopy, CalMMV is distantly related to the Japanese isolate of dendrobium mosaic potyvirus (DeMV‐J), but it showed no serological relationship to any of seven other potyviruses. The sequence of the 3′‐terminal 1306 nucleo‐tides of the viral genome was determined. The coat protein (CP) coding sequence is predicted to be 804 nucleotides in length, encoding a protein of 268 amino acids with a calculated mol. weight of 30 389. The 3′ noncoding region is 169 nucleotides long and is followed by a polyadenylate tract. The amino acid sequence of the CP of CalMMV was 73% homologous to that of DeMV‐J, but less than 66% to other potyviruses.
Ultrastructural Studies of the Intercellular Hypha aud Haustorium of Puccinia recondita f.sp. tritici
Authors: Hu G. G. , Rijkenberg F. H. J. 
Published: May 2008

AbstractThe ultrastructure of intercellular hyphae and D‐hati‐storia of P. recondita f.sp. tritici, and the host response to haustorial invasion, was investigated. The intercellular hyphae share common characteristics with those of other uredial stage rust fungi. Anastomosis was observed between intercellular hyphae. Two nucleoli were frequently observed in a single nucleus in the haustorium, indicating possible nuclear fusion between the two nuclei in D‐haustoria of this fungus. The close association of host organelles, such as the nucleus, Golgi bodies, endo‐plasmic reticulum, vesicles and mitochondria, with the developing haustorium, is described.
Effect of Combined Bacterial and Urea Treatment on Biodegradation of Wood by Basidiomycete Fungi
Authors: Ejechi B. O. 
Published: May 2008

AbstractA laboratory investigation of the effect of two ureolytic bacteria (Proteus sp. and Bacillus sp.) on growth of wood‐rot fungi (Gloeophyllum sepiarium, Gloeophyllum sp., Pleurotus sp. and Trametes sp.) in media and wood containing urea, was carried out. Biomass of the wood‐rot ftingi was markedly reduced in potato dextrose/peptone/ urea (PDPU) broth to which ureolytic bacteria was introduced after 4 days growth of the fungi. Interaction studies on non‐urea containing agar plates did not indicate any antagonism between bacteria and wood‐rot fungi while sterile filtrates from 24 h PDPU cultures of ureolytic bacteria indicated that presence of ammonia prevented or markedly reduced growth of the fungi. Bacterial ureolytic activity produced volatiles which reduced wood‐rot fungal growth. Biodegradation was markedly reduced in wood treated with urea and ureolytic bacteria before exposure to wood‐rot fungi. Similar treatment of wood previously inoculated with the fungi significantly retarded on‐going decay. Wood‐rot fungi isolated from treated wood showed reduced growth. Inhibition of wood‐rot fungal activity is attributed to production of ammonia by the bacteria and the stress imposed by the resultant hostile alkaline pH.
Histopathology of Infection of Minneola Tangelo by Alternaria alternata pv. dtri and the Effect of Host and Environmental Factors on Lesion Development
Authors: Solel Z. , Kimchi M. 
Published: May 2008

AbstractAfter inoculation of Minneola leaves with conidia of Alternaria alternata pv. citri, germ lubes randomly grew over the leaf surfaces. Twenty‐four h after inoculation, appressoria appeared over the epidermal cells; they formed infection hyphae that penetrated into the leaf, and developed intercellular branching hyphae which resulted in minute necrotic lesions. During the following 2–3 days, the lesions grew into large necrotic spots, subsequently accompanied by a dark discoloration of the veins extending from the lesions. Susceptibility of the leaves was negatively correlated with their age: mature leaves (approximately 2 months old) were very resistant to infection. Lesions developed faster when leaves were inoculated on the abaxial rather than the adaxial surface. There was no difference in disease severity on detached or intact leaves, or between leaves incubated in darkness or under natural light. Fruit were highly susceptible throughout the whole season.
RAPD‐based Molecular Probes for the Blackleg Fungus Leptosphaeria maculans (Phoma lingam): Evidence for Pathogenicity Group‐specific Sequences in tbe Fungal Genomes
Authors: Voigt K. , Schleier S. , Wostemeyer J. 
Published: May 2008

AbstractPolymerase chain reaction (PCR) primers, specific for the aggressive pathogenicity group of the rape seed pathogen Leptosphaeria maculans, were obtained according to the following experimental outline: DNA bands that differentiate between aggressive (A) and nonaggressive (NA) isolates were generated by the random amplified polymorphic DNA approach (RAPD). Differential RAPD bands were checked for pathogenicity group‐specificity and sequenced by a combination of chemical and dideoxynucleotide chain termination methods. Based on the DNA sequence longer and highly specific primer pairs for conventional PCR under stringent conditions were designed, which were tested on 97 isolates of L. maculans belonging to different pathogenicity groups. The primer pair specific for the aggressive pathogenicity group unequivocally identifies A‐isolates. The primer pair designed for the N A‐isolates. cross‐reacts with A‐isolates showing positive signals in 28 out of 63 cases. The combined application of A‐ and NA‐specific primers identifies all isolates unambiguously. The method does not require pure fungal cultures. L. macuians can be detected directly in infected plant material within a single working day. The experimental outhne presented in this communication is proposed as a general method for obtaining taxon‐specific PCR primer pairs.
Variation in Pathogenicity Among Isolates of Phytophthora dandestina
Authors: Purwantara A. , Fletr S. P. , Keane P. J. 
Published: May 2008

AbstractStudies on 25 isolates of Phytophthora dandestina collected from four states in southern Australia identified the presence of diversity in pathogenicity but not in morphology among isolates. Race 0 was found in all states except New South Wales, race 1 was found in all states, and races 2 and 3 were found only in Victoria and New South Wales, respectively. Race 4 was identified in Victoria and Western Australia. There was no apparent change in pathogenicity of the fungus following 10 (every 20 days) or 20 (every 10 days) cycles of subculturing. There was also no shift towards higher aggressiveness or virulence during 10 cycles of the fungus through susceptible or resistant cuitivars.
Cytochemistry of the Interaction between Wheat (Triticum aestivum) and Puccinia recondita f.sp. tritici Localization of Cellulose, Chitin, Glucose/Mannose, Galactose and Fucose
Authors: Hu G. G. , Rukenberg F. H. J. 
Published: May 2008

AbstractA study of the cytochemistry of the interaction between wheat and Puccinia recondita f, sp. tritici, using various enzyme‐ and lectin‐conjugated colloidal gold probes provided additional information on the nature and composition of the walls of fungal hyphae, the haustorial mother cell, the haustorial neck, the haustorial body, and the extrahaustorial matrix. Using a cellulase‐conjugated gold probe, cellulose (the major component of the host cell wall) was not detected in the extrahaustorial matrix or in the host tubules associated with the invading haustorium. Wheat germ agglutinin (WGA)‐gold conjugates, which detect chitin oligomers (N‐acetylglucosamine residues), bound to two inner wall layers of the intercellular hypha, four inner wall layers of the haustorial mother cell (HMC), and the wall layers of older haustorial bodies, WGA did not bind to the haustorial neck, the walls of the young haustorial body or the extrahaustorial matrix. Concanavalin A‐ (ConA‐) and Lentil agglutinin (LTA)‐gold complexes, which specifically recognize man‐nose/glucose residues, bound to the wall layers of intercellular hyphae, HMCs, haustorial necks and young haustorial bodies. Colloidal gold conjugates with peanut agglutinin (PNA) which detect galactose residues, soybean agglutinin (SBA) which are specific to both galactose and N‐acetylgalactosamine residues, and Helix pomatia agglutinin (HPA) which recognizes N‐acetylgalactosamine residues, respectively, bound to these residues in the sections, PNA and SBA labelled the cell walls of intercellular hyphae, HMCs, haustorial necks, young haustorial bodies and the extrahaustorial matrix, PNA and SBA also bound to the host cell wall and to the host extracellular matrix, HPA bound weakly to the walls of haustorial bodies and the extrahaustorial matrix, Ulex europeaus agglutinin (UEA 1)‐gold complex, specific to α‐fucose residues, bound to the wall layers of intercellular hyphae and HMCs, and bound weakly to the extrahaustorial matrix. The composition of wall layers of the haustorial body of P. recondita f, sp, tritici appears to change as the haustorium matures.