bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Inoculation with a Mild Strain of Tomato Aspermy Virus on the Growth and Yield of Tomatoes and the Potential for Cross Protection
Authors: Kuti J. O. , Moline H. E. 
Published: May 2008

AbstractMechanical inoculation of seedlings of 26 tomato cultivars with an attenuated strain of tomato aspermy virus (TAV‐M, ATCC # PV361) resulted in development of only mild symptoms, which had largely disappeared by the time the infected plants had begun to set fruit. Yield trials revealed that plants inoculated with TAV‐M when transplanted at the 6–8 leaf stage displayed no delay in fruit set and had yields only slightly less than uninoculated plants. Cross protection studies carried out in the greenhouse revealed that TAV‐M has the potential to interfere with infection of tomato seedlings by a more severe TAV strain (ATCC # PV127). ‘Pik‐Red’ seedlings inoculated with TAV‐M showed a significant reduction in symptom expression when challenged with the Blencowe strain of TAV 21 days after the initial inoculation with TAV‐M; interference was incomplete at 7 and 14 days.
Symptom Regulation Induced by Chicory Yellow Mottle Virus Satellite‐Like RNA
Authors: Piazzolla P. , Vovlas C. , Rubino L. 
Published: May 2008

AbstractCYMV‐T, CYMV‐C and CYMV‐RS are three strains of CYMV, a nepovirus isolated from chicory in Southern Italy. They are serologically indistinguishable, but display different electrophoretic and analytical ultracentrifugation patterns. In fact the RNAs obtained from CYMV‐T, when analyzed in 2.4% polyacrylamide cylindrical gels, showed the presence of a 170,000 mol. wt. satellite‐like RNA (CYMV‐T Sat RNA) and several other RNAs, whereas CYMV‐RS gave only the genomic RNAs and CYMV‐C, in addition, some ofthe RNAs present in CYMV‐T but not the Sat RNA.When these three strains were assayed on Nicotiana glutinosa L., CYMV‐C and CYMV‐RS elicited typical necrotic rings, whereas CYMV‐T infections were symptomless. The conclusions were drawn that CYMV‐T Sat RNA is another low mol. wt. RNA able to display viral disease regulation and that CYMV‐T, CYMV‐C and CYMV‐RS could represent an example of natural oscillation among different stages of RNA satellite emergence.
Growth of Foliage of Pigeon pea (Cajanus cajan [L.] Millsp.) and Disease Progress of Alternaria Blight
Authors: Singh U. P. , Zargar G. H. , Fazili M. A. 
Published: May 2008

AbstractVanderplank developed a model based on the logistic growth system to calculate the apparent infection rate (r) and to estimate plant disease progress. By estimating his r and p∧ (infection rate corrected for growth) the results were frequently negative. Kushalappa and Ludwig later developed another model for adequately correcting the host growth. The present model is a modification of Kushalappa and Ludwig's model in which the results are positive in case of Alternaria blight of pigeon pea (Cajanus cajan [L.] Millsp.). The disease intensity increased despite host growth resulting into an epidemic. A factor accounting for leaf fall due to blighting has been taken into consideration.
Phenylalanine Ammonia‐Lyase Activity and Anthocyanin Accumulation in Wounded Maize Mesocotyls
Authors: Pascholati S. F. , Nicholson R. L. , Butler L. G. 
Published: May 2008

AbstractActivity of phenylalanine ammonia‐lyase (E.C. 4.3.1.5) and anthocyanin accumulation were determined in wounded maize (Zea mays L.) mesocotyls. Mesocotyls were wounded with aluminum oxide and were placed in a 15 h light: 9 h dark photoperiod or in the dark. Extractable enzyme activity increased in response to wounding in the photoperiod but not in the dark. Anthocyanin accumulation in mesocotyls placed in the photoperiod decreased in response to wounding. The results are discussed with reference to phenylalanine ammonia‐lyase activity in mesocotyl tissue wounded or inoculated with fungal pathogens.
Diversity of the RNAs in Thirteen Isolates of Beet Necrotic Yellow Vein Virus in Chenopodium quinoa Detected by Means of Cloned cDNAs
Authors: Burgermeister W. , Koenig R. , Weich H. , Sebald W. , Lesemann D.‐E. 
Published: May 2008

AbstractComplementary deoxyribonucleic acids (cDNAs) to the four ribonucleic acid (RNA) species of isolate YU2 of beet necrotic yellow vein virus (BNYVV) were prepared by reverse transcription. The duplexes of these cDNAs were incorporated in the plasmid pBR322 and cloned into E. coli strain 5K. The insert sizes of the cDNA clones ranged from 280 to 2100 base pairs. In Southern blot hybridizations not all cDNAs specific for a particular RNA of BNYVV cross‐reacted. This suggests that they are complementaryto different regions of the respective RNA. In dot blot hybridization experiments sixteen out of eighteen cDNA clones detected all thirteen BNYVV isolates which were obtained from sugar beets originating from Yugoslavia, Italy, Switzerland, France and various regions in Germany and which were maintained in Chenopodium quinoa. Two cDNA clones specific for RNA‐3 failed to detect one German isolate. Pronounced differences between the thirteen virus isolates were seen when the electrophoretic migration of their RNAs was compared in Northern blot hybridizations. RNA‐1 and RNA‐2 of all isolates had the same sizes of 7100 and 5200 bases, respectively. The size, number and relative concentration of the smaller RNAs, however, varied greatly with different, isolates.
Effect of Co‐infection by Fusarium oxysporum and Cowpea Mosaic Virus on the Growth and Colonization of Cowpea Seedlings (Vigna unguiculata [L.] Walp.)
Authors: Chant S. R. , Gbaja I. S. 
Published: May 2008

AbstractCombined infection of cowpea seedlings (c. v. ‘California Blackeye”) by cowpea mosaic virus (CPMV) and Fusarium oxysporum induced greater losses in leaf area, fresh and dry weights than infection by either pathogen alone. The growth of seedlings infected by F. oxysporum f. sp. tracheiphilum was less than that of comparable seedlings infected by F. oxysporum f. sp. phaseoli. The virus infectivity of extracts of the trifoliate leaves of dual‐infected plants was significantly higher than that of comparable extracts from the leaves of plants singly infected with CPMV. The nature of the effects of multiple infection in cowpea is discussed.
Iron Bound‐Siderophores, Cyanic Acid, and Antibiotics Involved in Suppression of Thielaviopsis basicola by a Pseudomonas fluorescens Strain
Authors: Ahl P. , Voisard C. , Défago G. 
Published: May 2008

AbstractA Pseudomonas fluorescens strain (CHAo) involved in suppression of black root rot caused by Thielaviopsis basicola in the field, inhibited T. basicola when colonizing roots grown under sterile conditions or when grown on culture, media. Under these conditions it produced siderophores (iron chelating compounds), cyanic acid, and several antibiotics. Iron‐free siderophores inhibited neither the germination of endoconidia or chlamydospores nor the mycelial growth of T. basicola, but reduced the production of endoconidia. On the contrary, siderophores complexed with Fe3+ strongly inhibited mycelium growth and spore germination; free iron was less toxic than iron‐bound siderophores. Therefore, contrary to what was believed to date, siderophores seem to be toxic not because they deplete iron but because they increase its concentration to the point where it becomes highly toxic. Cyanic acid and the antibiotics also inhibited the growth of T. basicola. Whetherall these compounds are involved in disease control in the soil remains, however, to be determined.
Competition Between Typhula incarnata strains as a Source of Variation of Typhula blight in Winter Barley
Authors: Cavelier M. 
Published: May 2008

AbstractSeveral crosses between monokaryotic strains of Typhula incarnata Laschex Fr. have given rise to hypoaggressive dikaryons under laboratory conditions. Winter barley plants, preinoculated in cold chamber by these strains, were, fully protected against the harmful effects of the aggressive strains inoculated 15 days later. The experiments have stressed the role of plant cold‐hardening on their susceptibility to Typhula. Under field conditions, when inoculated to winter barley seedlings, a mixture of aggressive and nonaggressive strains produced an attack which was intermediate between the severe one of the former and the almost indiscernible one of the latter strain.Moreover, in cold chamber, mixed sclerotia from two equally aggressive strains induced as much damage as each strain inoculated separately.Insofar as the extent of barley infection by T. incarnata can be measured by the dry weight of the infected plants before stem elongation and by the number of ears at harvest, our results indicate the determinant role of the first infective strain upon the ultimate degree of the attack. The eventual role of crosses between strains is discussed.
Interrelationship between Nutrients, Pathogenicity and Phytoalexin Metabolism of Botrytis cinerea on Clover Leaves
Authors: Macfoy C. A. , Smith I. M. 
Published: May 2008

Abstract Botrytis cinerea spores suspended in 0.28 M glucose solution caused limited lesions on clover leaves, on which the clover phytoalexins maackiain and medicarpin accumulated to 1028 μg and 856 μg/g fresh wt respectively after 4 days incubation. During this time, little or none of the phytoalexin degradation products were detected. On the other hand, B. cinerea spores in sucrose casamino acids (SCA) liquid medium caused larger lesions than spores in glucose, and less maackiain and medicarpin (298 μg and 95 μg/g fresh wt respectively) and high concentrations of the degradation products were detected. B. cinerea mycelium in SCA also caused large lesions and both the phytoalexins and their degradation products were detected.,Sclerotinia laxa spores in 0.28 M glucose or its mycelium in SCA liquid medium did not cause any lesions apart from a minute necrotic fleck, and although phytoalexins were recovered from leaves inoculated with spores (67 μg and 78 μg/g fresh weight of maackiain and medicarpin respectively after 4 days) and leaves inoculated with mycelium (150 μg and 167 μg/g fresh wt maackiain and medicarpin respectively after 3 days), no phytoalexin degradation products were detected. The implications of, these results in understanding the interrelationship between nutrients, pathogenicity and phytoalexin metabolism are discussed.
Ultrastructure of Laticifers Modifications in Hevea brasiliensis Infected with Root Rot Fungi
Authors: Nicole M. , Geiger J. P. , Nandris D. 
Published: May 2008

AbstractThis paper presents some aspects of latex coagulation inside latice vessels of roots of Hevea brasiliensis infected by two fungi: Rigidoporus lignosus and Phellinus noxius. Three stages are described in latex coagulation: the phase of latex destabilisation characterized by the bursting of vacuoles and lysosomes membranes; the phase of latex coagulation characterized by the fusion of rubber particles and the disorganization of the cytoplasm; the formation of shots of rubber clumps indicating the final stage of coagulation.
Resistenz verschiedener Kultur‐ und Wildtomatenpflanzen (Lycopersicon spp.) gegenüber Botrytis cinerea Pers.
Authors: Urbasch I. 
Published: May 2008

Abstract Resistance of different cultivated and wild tomato plants (Lycopersicon spp.) to Botrytis cinerea Pers. 20 provenances of different cultivated and wild tomato plants (Lycopersicon spp.) were screened for resistance to Botrytis cinerea Pers. using an in vitro‐leaf necrosis test.The Botrytis resistance decreased with increasing age of the leaves corresponding to their insertion height (relative youth resistance respectively senescence susceptibility).The 6 B. cinerea‐isolates used for inoculation differed significantly in virulence. With increasing inoculum age a virulence reduction of the various B. cinerea‐isolates occurred. Within the investigated test plant collection 2 wild species –L. columbianum and L. hirsutum– proved to be resistant in each stage of development to all B. cinerea‐isolates and additionally showed field resistance.
The Effects of Cymbidium Mosaic Virus and Odontoglossum Ringspot Virus on the Growth of Cymbidium Orchids
Authors: Pearson M. N. , Cole J. S. 
Published: May 2008

AbstractTwo cultivars of Cymbidium orchid were mechanically inoculated with Odontoglossum ringspot virus (ORSV) and Cymbidium mosaic virus (CyMV), individually and in combination. ORSV was found to have an infection rate of 70% (as determined by ELISA), but seldom induced easily discernable leaf symptoms. CyMV had an infection rate of only 20%, but infected plants invariably produced a pronounced leaf mosaic either with or without necrotic streaks. Both viruses were found to reduce plant growth, the effects of CyMV being more severe than those of ORSV.
Auswinterungsschäden in Raigras‐Reinbeständen, die Bedeutung pilzlicher Krankheitserreger und ihre mögliche Eindämmung
Authors: Winter W. 
Published: May 2008

Abstract Winterkilling in puresown ryegrass, the importance of fungal pathogens and possibilities for their control I. Results from field trials with natural infection Rotten plants, incomplete stands, a reduced number of shoots and a decline in dry matter yield were observed after hibernations of perennial and Italian ryegrass. Isolations from damaged plants showed that the main pathogen was the causal agent of snow mould Monographella nivalis (Schaffn.) E. Müll., asexual stage Gerlachia nivalis (Ces. ex Sacc.) W. Gams et E. Müll., synonym Fusarium nivale Ces. ex Sacc. The following fungi were also isolated: Laetisaria fuciformis(Mc Alp.) Burds., synonym Corticium fuciforme (Berk.) Wakef., Gibberella avenacea Cook, asexual stage Fusarium avenaceum (Fr.) Sacc. and Fusarium culmorum (W. G. Sm.) Sacc.The field trials were located at 440 and 630 m a.s.l. These elevations correspond to plain and mid‐mountain climates, respectively. The tetraploid varieties ‘Lipo’, ‘Tetila’, ‘Citadel’ and ‘Bastion’ showed a higher level of resistance to snow mould compared to the diploid varieties ‘Ursus’, ‘Lemtal’, ‘Melino’ and ‘Pablo’. Tetraploid ryegrasses contaminated the soil with Gerlachia nivalis to a lesser extend than diploid ryegrasses.The influence of the date of cutting and of nitrogen fertilization in autumn on snow mould was also tested. Lowest values at both locations were observed when the last cutting occurred at the end of October. Severity was higher when the last cutting, took place earlier (mid September, end of September, mid October). Since parts of stands of the last cutting were strongly damaged by the cold, last cutting should take place in the middle of October, although infection with snow mould will not be as much reduced as if the last cutting was done at the end of October. The plant rotting caused by Gerlachia nivalis was increased with 80 kg N/ha in autumn compared with 40 kg N/ha.
The Influence of Plant Extracts on Phytotoxin Production and Growth Rate of Alternaria helianthi
Authors: Robeson D. J. , Strobel G. A. 
Published: May 2008

AbstractWhen liquid cultures of Alternaria helianthi were supplemented with aqueous extracts of leaf tissue of its host plant (sunflower), pronounced effects on both growth and production of the toxin deoxyradicinin were apparent. Very low levels of leaf extract stimulated toxin production but did not significantly affect growth, while higher levels markedly stimulated mycelial growth and at the same time toxin production was greatly suppressed. Leaf extracts of non‐host plant species were also stimulatory to phytotoxin biosynthesis.
Microwave Treatment to Eradicate Seed‐borne Pathogens in Cassava True Seed
Authors: Lozano J. C. , Laberry R. , Bermudez A. 
Published: May 2008

AbstractA high percentage of cassava seeds, collected from five different edapho‐climatic zones, were found infected by several fungal and bacterial pathogens. The incidence and severity of seed infections were not correlated with the climatic conditions at, harvest. These pathogens were eradicated from seeds by a microwave oven treatment (1400 W heating power, 2450 MHz) for 120 s. The effectiveness of this treatment depended on reaching an optimum temperature of 77°C. Several factors, such as container capacity, water volume and seed number can affect the time required to reach 77°C. An Arasan dust treatment after microwave exposure, reduced seed re‐infestation.
Observations on the Effect of Inoculating Cassava (Manihot esculenta) Plantlets with Fluorescent Pseudomonads
Authors: Hernandez J. M. , Laberry R. , Lozano J. C. 
Published: May 2008

AbstractSome 136 isolates of fluorescent pseudomonads were isolated from the rhizosphere of plants growing in 5 different ecosystems. Thirty‐four percent of these isolates inhibited the causal agent of cassava stem rot, Erwinia carotovora pv. carotovora, in vitro. One month old plantlets, produced by rooting the shoots of 4 cultivars in distilled water, were inoculated with a suspension (1.1 × 109 cells/ml) of each pseudomonad. Some isolates increased root weight by 95% over uninoculated controls two months after planting when inoculated at planting, and 15, and 30 days afterwards. Inoculated plants were free from symptoms of root pathogens and roots filled earlier than controls. Taxonomic studies showed that these bacterial isolates, were either Pseudomonas putida (90%) or P. fluorescens (10%).
Effect of NH3 on Chlamydospore Formation of Fusarium oxysporum f. sp. dianthi in an NH3‐Flow System
Authors: Löffler H. J. M. , van Dongen M. , Schippers B. 
Published: May 2008

AbstractConidia of Fusarium oxysporum on membrane filters on a sand bed saturated with a TRIS‐buffer in Conway vessels were exposed to different concentrations of NH3. NH3 was generated by bubbling air through NH4OH‐containing cylinders and pumped through the Conway vessels. Low concentrations of NH3 (15 ppm) stimulated chlamydospore formation in both germinated and ungerminated conidia. Higher concentrations of NH3 (150 ppm) inhibited chlamydospore formation. Ammonia had no apparent effects on the quality of the produced chlamydospores as measured by determining the persistence in soil.
Mycoplasma‐like Organisms Associated with Little Leaf Disease of Eucalyptus microtheca Muell.
Authors: Dafalla G. A. , Theveu E. , Cousin M. T. 
Published: May 2008

AbstractA little leaf disease has been observed in several plants of Eucalyptus microtheca Muell. grown in Wad Medani area, Sudan. The disease is characterized by general plant stunting, reduction in diameter and height of trunks of affected trees, yellowing and reduction in leaf size, shortening of internodes together with excessive proliferation of axillary shoots. Electron microscope observations on ultrathin sections have revealed the presence of pleomorphic bodies in the sieve elements of diseased but not of healthy plants. These bodies possess DNA strands, ribosome‐like granules and a three‐layered unit membrane well defined at high magnifications (> 100,000) suggesting a mollicute nature of these bodies. Studies using semi‐thin sections revealed the absence of helical forms. Thus, a mycoplasma‐like organism (MLO) is suspected to be the agent responsible for the disease. The results are discussed with reference to the economic and environmental importance of this tree species in the Sudanand, the possible threat of the disease to its cultivation.
Host‐Parasite Relationship in a Susceptible and a Resistant Rose Cultivar Inoculated with Sphaerotheca pannosa.
Authors: Conti G. G. , Bassi M. , Maffi D. , Bocci A. M. 
Published: May 2008

AbstractYoung leaves of two rose cultivars, one susceptible (rose Cardinal) and the other moderately resistant (rose Q. Elizabeth) to mildew infection, were either inoculated with Sphaerotheca pannosa or wounded with glass or metal needles. At different times after these treatments the presence of callose, lignin and phenolics in the infected or wounded cells was revealed by histochemical reactions. After either treatment no difference was found between the cultivars in the amount or earliness of deposition of callose or lignin, while phenolics were present in far larger amounts in the resistant cultivar. It is therefore suggested that one of the factors of rose resistance to powdery mildew might be the capacity to synthesize large amounts of phenolic compounds, also in view of the fact that the vacuoles of healthy epidermal cells are strongly electron opaque in rose Q. Elizabeth, while they are much more transparent in rose Cardinal.
Elicitation and Suppression of Phytoalexin and Isoflavone Accumulation in Cotyledons of Cicer arietinum L. as Caused by Wounding and by Polymeric Components from the Fungus Ascochyta rabiei
Authors: Kessmann H. , Barz W. 
Published: May 2008

AbstractShortly after sowing cotyledons of chickpea (Cicer arietinum) start to accumulate the isoflavones biochanin A and formononetin together with their 7‐0‐glucosides and their 7‐0‐glucoside‐6″‐malonates. The additional accumulation of the pterocarpan phytoalexins medicarpin and maackiain can be induced by wounding of the cotyledons. Treatment of sliced cotyledons with a crude elicitor fraction obtained from the growth medium or the mycelium of the chickpea pathogenic fungus Ascochyta rabiei (Pass.) Lab. leads to a dramatic increase in the level of numerous aromatic compounds, especially of the isoflavone aglyca and the phytoalexins. Accumulation of isoflavone conjugates is not altered by elicitor treatment as shown by time course studies, and dose‐response curves.A protein preparation (“suppressor”) isolated from the culture filtrate of the same fungus was shown to inhibit the accumulation of isoflavone aglyca, isoflavone conjugates and phytoalexins in the sliced cotyledons.The possible relevance of elicitor‐suppressor counteraction with regard to the defence mechanisms of the host plant is discussed.
Une phytotoxine de Xanthomonas campestris pv. vasculorum
Authors: Ducourneau C. , Auriol P. 
Published: May 2008

Abstract A phytotoxin from Xanthomonas campestris pv. vasculorum I. Purification and partial characterization Xanthomonas campestris pv. vasculorum, the causal agent of sugarcane disease produces, when maintained in pure culture, a host selective phytotoxin. The molecule obtained at a high purity level is a strongly acid polyalcohol.
Seasonal Variation in Sporulation of Phytophthora infestans
Authors: Sujkowski L. S. 
Published: May 2008

AbstractSporulation ability of two isolates of Phytophthora infestans maintained on potato tuber slices of a susceptible cv. ‘Bintje’ and on‐rye agar medium was studied for four years (1981–1984). This feature of the fungus was shown to vary in particular seasons during the year.Significantly higher sporulation density per cm2 of aerial mycelium on potato tuber slices was observed in winter and late autumn while significantly lower sporulation was found in spring. Similar tendencies were observed when one of the isolates was cultivated on rye agar medium under controlled conditions. Positive correlation was found between sporulation patterns of isolates of the fungus maintained on rye agar and on tuber slices. Hypothesis has been proposed that these changes are due, to a biorhythm in the fungus.
Relations Between Biomass Accumulation and Infection by Vesicular‐Arbuscular Mycorrhizal Fungi in Cassava as Affected by Planting Date
Authors: Ayanru D. K. G. 
Published: May 2008

AbstractRoots of 12, 3‐month‐old, field‐propagated clones of cassava (Manihot esculenta Crantz) were more heavily mycorrhizal in the dry (Jan.–March and Oct.–Dec.) (39–83 %) than in the wet season (April–Sept.) (20–71%). Mean dry weights (biomass) of roots and shoots in the wet season (3.8–7.9 and 9.7–19.1 g/plant) were higher (P = 0.01) than in the dry season (2.1–5.9 and 5.4–12.8 g/plant, respectively). Clones with symptoms of the African cassava mosaic disease (ACMD) were less mycorrhizal, (20–69%) than mosaic symptom‐free clones (51–83%). Higher colonization of roots of the clones by indigenous fungal symbionts and lower biomass accumulation in the dry season are attributed mainly to soil moisture and other effects, while reduced infections in cassava with ACMD symptoms may be due to ACMD‐induced reductions in carbohydrate levels.