bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors affecting ascorbic acid biosynthesis in chickens: III. Effect of dietary fluoride on l‐gulonolactone oxidase activity and tissue ascorbic acid (AsA) concentration
Authors: Maurice D. V. , Lightsey S. F. , Abudabos A. , Toler J. E.
Published: March 2003

The inconsistent beneficial responses to dietary ascorbic acid (AsA) may be due to dietary factors that alter biosynthesis or tissue turnover of AsA. It has been suggested on the basis of altered tissue AsA that dietary fluoride is a determinant of biosynthesis in chickens. Fluoride may enter the food chain of poultry via industrial contamination, feed ingredients and drinking water. The goal of this study was to ascertain whether dietary fluoride at 300 mg/kg influences l‐gulonolactone oxidase (GLO) activity in commercial meat‐type chickens. The experimental diet was fed from day‐old to 3 weeks and responses measured. Growth and feed conversion were not affected by fluoride in the diet. Dietary fluoride neither inhibited nor enhanced GLO activity nor did it increase or decrease AsA concentration in plasma, liver, kidney, adrenal gland and muscle (pectoralis major). Tissue AsA concentration in ascending order was adrenal > liver > kidney > pectoralis major > plasma. The results are consistent with that reported for the rat and calculations based on the results eliminate fluorine contamination for the inconsistent responses of immature chickens to dietary AsA.
Spatial pattern of the Río Cuarto corn disease vector, Delphacodes kuscheli Fennah (Hom., Delphacidae), in oat fields in Argentina and design of sampling plans
Authors: Garat O. , Trumper E. V. , Gorla D. E. , Perez‐Harguindeguy N.
Published: March 2003

The spatial pattern of the Río Cuarto Corn Disease vector, Delphacodes kuscheli (Hom., Delphacidae), was analysed in oat fields within the endemic area of the disease, during the growing seasons 1993 and 1994. The spatial pattern was analysed by fitting the probabilistic models Poisson and negative binomial and estimation of single‐date and overall aggregation indices. The population of the different stage classes, sex, and wing forms showed a significant trend to aggregation as the negative binomial model fitted the observed frequency distributions in more than 78% of the cases (sampling dates) while the Poisson model fitted well in only 28% of cases or less. Single‐date aggregation index, CA, ranged from 0.3 to 0.84. Overall (whole season) aggregation index, CA*, estimated through the Bliss and Owen’s regression method, ranged from 0.18 (female adults) to 1.08 (nymphs I–II), indicating a moderate degree of aggregation compared with other planthopper species. There were no significant relationships between aggregation and population density. The minimum number of sampling units and critical lines for sequential sampling plans were calculated based on the estimation of CA* for the precision levels (D) 0.1, 0.2 and 0.3. Even low degrees of aggregation, like that of adults, demand much more sampling effort than randomly distributed populations, particularly at high densities. General implications and limitations of the proposed sampling plans for monitoring the vector population abundance are discussed.
Notes on the mating system of Hylesinus varius (F.)(Col., Scolytidae), a putatively bigynous bark beetle
Authors: Løyning M. K. , Kirkendall L. R.
Published: March 2003

Abstract: Previous research has left confusion about central features of the mating system of the common ash bark beetle Hylesinus varius; in particular, reports conflict as to whether this species is monogynous or bigynous. It was found that females initiated egg tunnel construction; copulation takes place either on the bark in the initial phase of egg tunnel construction, or inside the tunnel system. Observations of one male copulating with several females and of solitary females in galleries with eggs suggested that the males sometimes leave after copulation. In contrast to findings for populations in Slovakia, Norwegian male H. varius were most commonly paired with only one female. Bigynous galleries contained significantly more eggs than monogynous galleries, but bigynous males did not double their reproductive success as found in some other bigynous bark beetles. This suggests that bigynous galleries at first are the work of one female but some males are later joined by a second female.
Effects of repeated thermic and antibiotic treatments on a Trichogramma (Hym., Trichogrammatidae) symbiont
Authors: Pintureau B. , Chapelle L. , Delobel B.
Published: March 2003

Each individual of all populations of the thelytokous species Trichogramma cordubensis is infected by Wolbachia. Populations are composed of females, a few rare males and some intersexual or gynandromorphic individuals often capable of normal reproduction as females. Antibiotic (minocycline) and high temperature (30°C) treatments inactivate Wolbachia and induce male production. After these treatments, the sex ratio depending on the remaining frequency of thelytoky shows a genetic variability. Effect of cycles with and without treatments (minocycline or 30°C) on the thelytokous reproduction of ‘individuals’ (one ‘individual’ being one Trichogramma+n Wolbachia) was studied. The resistance of thelytokous reproduction to 30°C but not to minocycline, probably due to Wolbachia genes, increased. It is concluded that potentialities of adaptation to high temperature exist in Wolbachia and can explain a part of the spreading of these symbionts among host populations.
Methyl iodide: an alternative to methyl bromide for insectary fumigation
Authors: Waggoner M. , Ohr H. D. , Adams C. , Sims J. J. , Gonzalez D.
Published: March 2003

Methyl bromide is a powerful fumigant that has been widely used in soil, structural and commodity fumigations for many years. Because of its designation as an ozone‐depleting chemical and resulting federal and international laws, it is scheduled to be removed from production in the year 2001. In experiments testing the suitability of methyl iodide as a replacement chemical for insectary and quarantine fumigations, the chemical appears to be as effective or more effective than methyl bromide. Increased symptoms of plant toxicity to methyl iodide are evidenced only at concentrations above those required to kill insect pests.
Effect of container type on suitability of the pathogen Serratia marcescens ‐ Microctonus hyperodae (Hym., Braconidae) association to indicate parasitoid oviposition attempts
Authors: McNeill M. R.
Published: March 2003

To minimize the risk that introduced entomophagous biological control agents may pose to native and beneficial insect species, identification of likely nontarget hosts is required before release is considered. A novel technique, in which the parasitoid acts as a vector of a bacterium pathogenic to potential hosts, has been used as an indicator of parasitoid ovipositional activity even when subsequent development of the parasitoid egg within the ‘host’ does not occur. In this study the application of this technique was examined in relation to container type using the facultative bacterium Serratia marcescens in association with the parasitoid Microctonus hyperodae. Two permissive host weevil species, Listronotus bonariensis and Irenimus aequalis, were exposed for 72 h to M. hyperodae treated with either distilled water or S. marcescens suspension in either Petri dishes or cages. Weevil septicaemia was significantly higher when exposed to S. marcescens‐treated parasitoids than water‐treated parasitoids (P < 0.001), with no difference in mortality between weevil species. Septicaemia was significantly higher in the Petri dishes than in cages (P < 0.001). This was attributed to improved survival of S. marcescens in the Petri dishes compared with cages. Total parasitoid activity (combined septicaemia and parasitism) for I. aequalis was higher in Petri dishes than in cages and far exceeded field parasitism. Petri dishes provide an environment for constant interaction between parasitoid and target host and thereby provide a conservative indication of parasitoid host range. However, cages may be more suitable to conduct host range studies because the ability to manipulate the environment. Potential refinements to the parasitoid‐bacteria technique include methodology that enhances viability of the bacterium under cage conditions.
Pine shoot beetle, Tomicus piniperda (Col., Scolytidae), responses to common green leaf volatiles
Authors: Poland T. M. , Haack R. A.
Published: March 2003

We tested the hypothesis that green leaf volatiles (GLVs) disrupt the response of overwintered pine shoot beetles, Tomicus piniperda (L.) to multiple‐funnel traps baited with the attractive host volatile α‐pinene. A combination of four GLV alcohols, 1‐hexanol (E)‐2‐hexen‐1‐ol (Z)‐2‐hexen‐1‐ol, and (Z)‐3‐hexen‐1‐ol, caused 54 and 36% reduction in the number of pine shoot beetles captured in two separate trapping experiments. Similarly, a combination of the four alcohols plus two GLV aldehydes, hexanal and (E)‐2‐hexenal, caused 38% reduction in the number of pine shoot beetles captured compared with α‐pinene alone. A blend of the two GLV aldehydes was not disruptive. None of the four GLV alcohols nor the two GLV aldehydes were disruptive when tested individually. The finding that the blend of four GLV alcohols reduced attraction of T. piniperda supports the general hypothesis that GLVs common to nonhost angiosperms are disruptive to conifer‐attacking bark beetles (Scolytidae).
Untersuchungen über die Fichtengespinstblattwespen Cephalcia spp. Panz. (Hym., Pamphiliidae) IV. Massenwechsel von Cephalcia abietis L. im oberschwäbischen Forstrevier Erolzheim (Fbz. Ochsenhausen)	*
Authors: Eichhorn O. , Bogenschütz H.
Published: March 2003

Studies on the web‐spinning spruce sawflies of the genus Cephalcia spp. 1 Panz. (Hym., Pamphiliidae). IV. Population dynamics of Cephalcia abietis L. in Upper Suabia.

The paper describes the population dynamics of the spruce false webworm Cephalcia abietis L. in an 80‐year‐old spruce stand in the forest area of Erolzheim near Ulm (Germany) between 1986 and 1996. Emerging sawflies and adult parasitoids were trapped in groundphotoeclectors and the descending host larvae in funnel‐traps. About 7000 host larvae and prepupae were dissected to evaluate the degree of parasitism. The emergence pattern of the sawfly was determined as well as the duration of the feeding period. The development of the majority of the sawfly individuals lasted 3 years; during the warm summer of 1994 univoltinism was observed in 36% of the population. Temperature was ascertained as the key factor for the variable duration of the dormancy and for the population dynamics of the forest pest. Since 1986, the year of heavy feeding, the density of emerging females, of descending larvae, and of prepupa in the soil decreased finally to a subepidemic level in 1996. The sex ratio (SI) of different host stages averaged from 0.37 to 0.54. In the yellow prepupae ‐ amounting to 11% of the total population ‐ males were predominating (SI=0.16). The annual average number of full‐grown and developing eggs per female varied between 21 and 53, the total number of all oocytes between 46 and 112 (average 79). The complex of parasitoids of Cephalcia abietis consists of the egg parasitoid Trichogramma cephalciae, nine primary larval parasitoids (eight ichneumonids, one tachinid), and the hyperparasitoid Mesochorus nov. sp. Within 5 years the average of the total (effective) parasitism of descending larvae amounted to 74%, of prepupae in October to 45%, and of emerging adults to 40%. The possible reasons for the discrepancies are discussed, taking into account the effects of a single parasitoid species.
Prey selection and foraging behaviour byPterostichus cupreusL. (Col., Carabidae) under laboratory conditions
Authors: Mundy C. A. , Allen‐Williams L. J. , Underwood N. , Warrington S.
Published: March 2003

Abstract:Several authors have indicated that carabid beetles offer potential as predators of insect pests on arable crops, but this potential is reduced by their limited ability to climb the crop plants. In the current investigation an initial laboratory experiment indicated that seven species of carabid beetles commonly found in arable fields in the UK would feed on both aphid and collembolan prey.Pterostichus cupreusL. andBembidion guttulaFabr. were found to accept both live and dead aphids and collembolans. In further laboratory investigationsP. cupreusexhibited greater consumption of the cereal aphidMetopolophium dirhodumWalker than the alternative prey speciesHeteromurus nitidus, Templeton (Collembola, Entomobryidae) and there was some indication of preference for the aphid prey as these were often consumed first. Significantly more handling time was required for the consumption ofM. dirhodumcompared toH. nitidus.The treatments whereP. cupreuswas given a diet of aphids or collembolans prior to the prey choice experiment, did not appear to influence the number or type of prey items consumed.

Using a four‐arm olfactometerP. cupreusreacted positively to the volatiles from collembolans, but gave a less clear response to those from the cereal aphidM. dirhodum. In an artificial field arenaP. cupreusreadily climbed barley plants in search ofM. dirhodum, perhaps as a response to volatile emissions, but this behaviour changed whenH. nitiduswere introduced onto the substrate of the arena. Although the current results indicated thatP. cupreushas potential for the control of cereal aphids, the presence of alternative prey appeared to reduce this potential and suggest that the carabid is an opportunistic feeder.
Binomial sampling as a cost efficient sampling method for pest management of cabbage root fly (Dipt., Anthomyiidae) in cauliflower
Authors: Bligaard
Published: March 2003

A binomial (presence–absence) sampling plan has been developed based on the relationship between the proportion of cauliflower plants having visible cabbage root fly eggs (Delia radicum L.) exposed on the soil surface around the plant stem and the mean density of eggs per plant. The Kono–Sugino’s model was fitted to a total of 125 population estimates, each based on 10 plant samples collected from cauliflower fields in 1994 and 1995 (P=0.001; R2=0.64). When the model was compared with an independent data set consisting of 39 population estimates collected in 1995, an analysis of covariance showed no significant differences between the regression lines. The efficiency of the binomial method was compared with absolute sampling in terms of relative precision and cost efficiency. The binomial method had a high coefficient of variation, RV≈ 0.85, due to large biological error. In spite of this, binomial sampling was more cost efficient than the applied soil sampling when between 10 and 30 plants were examined for the presence of visible eggs.
Sexual receptivity and age in Glossina pallidipes Austen (Dipt., Glossinidae)
Authors: Olet P. A. , Opiyo E. , Robinson A. S.
Published: March 2003

The recent success of the sterile insect technique (SIT) in eradicating Glossina austeni from Zanzibar has stimulated interest in applying this technology to control Glossina pallidipes. However, little is known about the mating behaviour of this species in relation to the development and implementation of an effective SIT programme. The effect of age on male and female receptivity to mating was evaluated together with copulation duration, sperm transfer and the growth of the accessory gland and follicle A in males and females, respectively. Females and males reached their optimal sexual receptivity 9–13 days after emergence. Mean copulation duration was 20–30 min for mature males and females. The growth of follicle A and the accessory gland (apical body) was a function of age of females and males, respectively. Ovulation was not observed in virgin females up to 15 days of age whereas mated females ovulated by day 9. Males aged 7–15 days were equally effective in inseminating. Cages of males and females of different ages were set up to monitor puparial production in relation to optimization of mass rearing. The results are discussed in relation to the development of an efficient mass rearing protocol for this species and an optimal release strategy for sterile males.
Development and reproduction of Myzus persicae and Aphis fabae (Hom., Aphididae) on selected weed species surrounding sugar beet fields
Authors: Fernandez‐Quintanilla C. , Fereres A. , Godfrey L. , Norris R. F.
Published: March 2003

Abstract:  Myzus persicae (Sulzer) and Aphis fabae (Scop.) are two major aphid species colonizing sugar beet. They have a very wide host range adapting to a large number of plant families and species. A series of cage experiments, conducted under ‘winter’ and ‘summer’ growth chamber conditions, showed that both species have the potential to use winter and summer weeds that are usually present in the vicinity of and within sugar beet fields as secondary hosts. Among all the weeds tested, Veronica hederifolia L. and Solanum nigrum L. were the most suitable for M. persicae. Although Brassica kaber (DC.) Wheeler was the weed species associated to the highest reproduction rate of this aphid, V. hederifolia showed a higher intrinsic rate of population increase due to the shorter prereproductive period of the aphid. Amsynckia intermedia Fish. and Mey and Amaranthus retroflexus L. were the most suitable weed hosts for A. fabae.
First record of Eurytoma schreineri Schreiner (Hym., Eurytomidae) in Greece and some observations on its phenology
Authors: Koveos D. S. , Katsoyannos B. , Broufas G. D.
Published: March 2003

Abstract:  The occurrence of Eurytoma schreineri Schreiner infesting apricots is reported for the first time in Greece. Some preliminary observations on its phenology, main morphological characters and differences from other related species are mentioned.
Utilisation of morphological features in life table studies of Liriomyza huidobrensis (Dipt., Agromyzidae) developing in lettuce
Authors: Head J. , Walters K. F. A. , Langton S.
Published: March 2003

Abstract: A method of distinguishing different larval instars of Liriomyza huidobrensis morphologically, using measurements of the cephalopharyngeal skeleton was developed. The growth ratios of cephalopharyngeal skeletons between first and second and second and third instar larvae were 1.80 and 1.47, respectively, enabling clear separation to be achieved for experimental work. Using this method the development rates of the immature stages of L. huidobrensis feeding on Lactuca sativa were determined under constant temperatures of 11, 16, 19, 26 and 28 ± 1°C and were shown to increase linearly with temperature over the range investigated. The theoretical lower threshold temperatures for development from oviposition to the end of each larval instar or pupal stage were 5.35, 6.30, 6.20 and 5.70°C, respectively. The overall threshold temperature for development from oviposition to 50% adult emergence (5.70°C) was used to calculate degree‐day (DD) requirements for development from oviposition to each larval instar or pupal eclosion, which were 84.3, 30.1, 58.9, 143.7 DD, respectively. The use of these data for optimizing the timing of application of control agents which are effective against specific developmental stages is discussed.
Pathogenic Capacity of Helminthosporium spiciferum: Foliar Parasite of Rice in Morocco
Authors: Ennaffah B. , Touhami A. Ouazzani , Douira A.
Published: March 2003

In this study, artificially inoculation of six rice varieties widely cultured in the Gharb with Helminthosporium spiciferum showed different sensitivities against this isolate used. The foliar lesions are different from those noted on the plants of rice inoculated by Helminthosporium oryzae. Oryza sativa = rice/Helminthosporium spiciferum/ symptoms.
Untersuchungen zur Abtötungseffizienz der Persäuren Degaclean und Clarmarin und dem Katalase‐Hemmer KH10 der Fa. Degussa gegen die beiden Quarantänebakterien Clavibacter michiganensis ssp. sepedonicus und Ralstonia solanacearum in wässeriger Suspension und im Abwasser der stärkeproduzierenden Industrie
Authors: Niepold F.
Published: March 2003

Zusammenfassung

Die Wirkung von zwei neuen Persäuren (der Percarbonsäure Clarmarin und der Peressigsäure Degaclean) der Firma Degussa, Frankfurt, wurde an den beiden Quarantänebakterien Ralstonia solanacearum und Clavibacter michiganensis ssp. sepedonicus zur Abtötung erprobt. Um möglichst praxisbezogen zu arbeiten, wurde das Abwasser einer namhaften deutschen stärkeverarbeitenden Fabrik verwendet. Die natürlich im Abwasser vorkommende Mikroorganismen‐Population diente als Standard, um die Effektivität von herkömmlichen bakterizid wirkenden Substanzen im Vergleich zu den beiden Persäuren zu testen. Dabei zeigte sich, dai die Katalasen der Mikroorganismen eine erhebliche Aktivitätseinbuie bei den Persäuren verursachten. Zu ihrer Inaktivierung war der Einsatz des Katalase‐Hemmers (KH10) notwendig, da eine Anwendung von Persäuren alleine 20.000 ppm erforderlich machte bei einer Standard – Inkubationszeit von 20 min. Mit einer Konzentration von 2000 ppm eines Clarmarin/KH10 (1 : 1) Gemisches und der Standard – Inkubationszeit konnten sämtliche im Abwasser der stärkeverarbeitenden Fabrik vorhandenen Mikroorganismen abgetötet werden, während alle anderen getesteten bakteriziden Substanzen, darunter auch das Perhydrol (herkömmliches Wasserstoffperoxid), nur wenig die Vitalität der Mikroorganismen‐Population beeinfluite.
Department of Biological Sciences, University of Zimbabwe, Harare, Zimbabwe
Authors: Frederickson D. E. , Monyo E. S. , King S. B. , Odvody G. N. , Claflin L. E.
Published: March 2003

The etiology of a leafspot disease of pearl millet in Zimbabwe was investigated using Koch’s postulates. Bipolaris sp., Exserohilum sp., and bacteria, were isolated from lesions but only bacterial isolates produced the original symptoms following inoculation of a susceptible pearl millet line, 852B. Biochemical and physiological tests, including LOPAT, indicated the bacterium was the fluorescent pseudomonad, Pseudomonas syringae. This represents the first report of P. syringae on pearl millet in Africa.
Biologische Bundesanstalt für Land‐und Forstwirtschaft, Institut für Pflanzenvirologie, Mikrobiologie und biologische Sicherheit, Braunschweig, Germany
Authors: Hoffmann K. , Uhde C. , Lesemann D. ‐E. , Sackey S. T. , Adomako D. , Vetten H. J.
Published: March 2003

Immunoelectron microscopy (IEM) and enzyme‐linked immunosorbent assay (ELISA) studies with polyclonal antibodies (PAbs) indicated that the isolates 1A, Nsaba, and Kpeve of cacao swollen shoot virus (CSSV; genus Badnavirus) are serologically distinct. Out of these isolates, only 1A was reliably detected from infected cacao trees with the homologous PAbs. To improve serological detection of the isolates Nsaba and Kpeve by the application of monoclonal antibodies (MAbs), virion preparations of CSSV‐1A, ‐Nsaba and ‐Kpeve were used to immunize mice. Although immunization with CSSV‐1A yielded a large number of 1A‐specific MAbs, no Nsaba‐ or Kpeve‐specific MAbs were obtained after immunization with these isolates. Instead, the latter exclusively led to the production of MAbs which reacted only with isolate 1A. Epitope characterization of 1A‐specific MAbs using different ELISA procedures, IEM and Western blot experiments showed that three of the 1A‐specific MAbs detected a continuous epitope [sodium dodecyl sulphate (SDS)‐stable] and nine MAbs reacted with conformation‐dependent epitopes (SDS‐labile). Direct adsorption of virus particles to microtitre plates in antigen‐coated plate ELISA affected epitope stability in a similar fashion as SDS treatment of virions. When comparing the sensitivity of CSSV detection by MAbs and PAbs in various ELISA formats, MAbs were slightly more sensitive than PAbs in CSSV detection from plant sap. Using the panel of available 1A‐specific MAbs for triple antibody sandwich‐ELISA analysis of 31 CSSV samples from different cacao growing areas of Ghana revealed the occurrence of four serotypes in the samples containing CSSV‐1A isolates. In addition, the serological reaction patterns of the MAbs correlated well with the geographic origin of the isolates, thus giving further indications about the regional distribution of CSSV 1A‐like isolates in Ghana.
Occurrence of Different Tospoviruses in Vegetable Crops in Argentina
Authors: Gracia O. , De Borbon C. M. , De Millan N. Granval , Cuesta G. V.
Published: March 2003

Significant damage on vegetable crops by tospoviruses had occurred sporadically in Argentina in the past but since 1994, severe outbreaks have been recorded every year. The crops that have been most affected, tomato, lettuce, and pepper, were surveyed in the provinces of Mendoza and Buenos Aires in 1994–95 and 1995–96. A few weeds and miscellaneous crops were also collected. A total of 543 samples showing symptoms typical for tospoviruses were analysed by double‐antibody sandwich‐enzyme‐linked immunosorbent assay with polyclonal antibodies to groundnut ringspot tospovirus (GRSV), impatiens necrotic spot tospovirus (INSV) and tomato spotted wilt tospovirus (TSWV). The 339 samples collected in 1995–96 were also assayed for tomato chlorotic spot tospovirus (TCSV). In addition, the incidence of tospoviruses in tomato crops was assessed in 41 farms representing 310 ha and 10 cultivars. GRSV was identified in 222 samples (40.8%), TSWV in 194 samples (32.7%), TCSV in 50 samples (14.7%), INSV was not detected and 77 samples did not react with the antisera used. TSWV was found to prevail in Buenos Aires and GRSV in Mendoza. Mixed infections were not found in this survey. In tomato crops the mean incidence of tospoviruses was 33%. These results show that the disease formerly assigned to TSWV, is caused by at least three tospoviruses.
Concentric Bodies in a Parasitic Fungus of Malva sylvestris (Malvaceae) Pollen
Authors: Classen B. , Amelunxen F. , Blaschek W.
Published: March 2003

Ultrastructural examinations revealed concentric bodies in hyphae of a parasitic ascomycete, infecting pollen of Malva sylvestris ssp.mauritiana. These structures consist of three concentric zones and are similar to those found in mycobionts of several lichens and only a few nonlichenized ascomycetes. Typical septal pores of ascomycete hyphae were present, usually plugged by electron‐dense material and associated with one or more Woronin bodies.
Root‐colonizing Fungi from Oilseed Rape and their Inhibition of Verticillium dahliae
Authors: Alström S.
Published: March 2003

Root‐colonizing fungi obtained from thoroughly washed root segments of symptomless young oilseed rape plants growing in field soil were examined for their inhibitory effect on the wilt fungus, Verticillium dahliae Kleb. The isolated fungi that were possible to identify belonged to the different genera Trichoderma, Gliocladium, Mortierella, Fusarium and Alternaria. Oilseed rape seedlings from seeds exposed to both sporulating and nonsporulating fungal isolates were shown to be colonized by their hyphae in gnotobiotic conditions and the emergence/root growth was significantly affected in their presence. Inoculation with a few isolates not only covered the root surface but also seemed to extensively colonize the inner root cortical tissues partly by producing characteristic structures in the roots. All of these suppressed the pathogen in in vitro assays but the mode of suppression in most cases did not seem to be due to production of antifungal substances. In nonsterile field soil, several of the isolates conferred protection against V. dahliae by delaying symptom development. None of the isolates was shown to increase wilt symptoms. In addition to protection, two isolates, yet to be identified, also showed increased shoot dry weight compared with that of healthy controls. A majority of the isolates showed proteolytic activity whereas only three produced chitinolytic enzymes.

Results for the isolates obtained by the method selected for this study could be considered as a starting point for evaluating antagonists capable of both competing for root colonization and preventing root infection, with the final aim being to achieve successful biological control of the wilt fungus.
Genetic Diversity in Ralstonia solanacearum Strains from Mauritius using Restriction Fragment Length Polymorphisms
Authors: Dookun A. , Saumtally S. , Seal S.
Published: March 2003

Race 1, biovar III of Ralstonia (synonym Pseudomonas) solanacearum, causal organism of bacterial wilt, has been reported in Mauritius on several crops and plant species. The genetic relationship among 38 strains isolated from potato, tomato, bean and anthurium was determined by restriction fragment length polymorphisms (RFLPs). After hybridization with probe 5a67, five RFLP patterns could be distinguished. Types V and I were most commonly encountered. A common band of approximately 6.5 kb was found in 35 strains. Type I pattern consisted of only this band and was observed in 12 out of 16 anthurium strains tested. Type V was associated with 12 out of 16 potato strains and consisted of a band of approximately 3.3 kb in addition to the one observed in type I. RFLP patterns II, III and IV were less frequently encountered. The RFLP analysis showed that genetic diversity was present in race 1, biovar III strains. The relationship between the host and RFLP pattern is discussed.
Host Specialization among Vegetative Compatibility Groups of Verticillium dahliae in Relation to Verticillium longisporum
Authors: ZEISE K. , VON TIEDEMANN A.
Published: March 2003

A collection of 24 isolates of Verticillium dahliae and 10 isolates of Verticillium longisporum originating from nine different host plants and from several geographic regions was tested for host specificity on 11 economically important crops such as potato, tomato, strawberry, linseed, three legumes and four Brassica species. In order to reveal host specificity the potential of each isolate to induce disease and affect plant yield was recorded for all isolate–host combinations. The collected data were statistically processed by means of a cluster analysis. As a result, the host range of individual isolates was found to be more dependent on the vegetative compatibility group (VCG) of the isolate than on its original host plant provenance. Twenty‐two out of 24 V. dahliae isolates belonged to either VCG 2B or 4B. VCG 2B isolates showed specificity for legumes, strawberry, potato and linseed, whereas VCG 4B was specifically virulent on potato, strawberry and linseed. Subgroups within VCG 2B and 4B almost lacking any host preference were designated 2B* and 4B*. Three isolates from VCG 2B*, however, severely attacked tomato which is a host outside the authentic host range of VCG 2B. The pathogenicity of V. longisporum isolates was restricted to cruciferous hosts. Conversely, cruciferous plants were not affected by isolates from VCGs 2B and 4B of V. dahliae. This lack of cross‐infectivity of certain subpopulations of V. dahliae and of V. longisporum may be useful in the management of this soil‐borne wilt disease.
Rhizobacteria‐mediated Induction of Systemic Resistance (ISR) in Tomato against Meloidogyne javanica
Authors: Siddiqui I. A. , Shaukat S. S.
Published: March 2003

The two rhizobacteria Pseudomonas aeruginosa strain IE‐6S+ and P. fluorescens strain CHA0 used as bare root‐dip treatment or as soil drench substantially reduced Meloidogyne javanica juvenile penetration into tomato roots under glasshouse conditions. To better understand the basis of antagonism, the mode of action of the bacterial antagonists was investigated. The ability of bacterial inoculants to stimulate induced systemic resistance against the nematode was demonstrated in split‐root‐trials, where the root system of a single tomato plant was spatially divided into two separate parts. Application of IE‐6S+ to one half of the split‐root system caused a significant (42%) systemic reduction in nematode penetration in the other half of the split‐root system. CHA0 applied in the same manner reduced nematode infection similarly, by 29% over the controls. The population sizes of the strains IE‐6S+ and CHA0 were compared in order to determine if low degree of ISR by CHA0 could be attributed to a reduction in root population size. Populations of the strain CHA0 in the rhizosphere was higher during early growth stages of tomato while IE‐6S+ colonized relatively heavily during the later growth stages. Only strain IE‐6S+ was reisolated from the inner root tissues. Neither of the bacterium was isolated from the rhizosphere and inner root tissues of tomato from the non‐bacterized halves. Bacteria with systemic nature (IE‐6S+) induce systemic resistance in plant to a relatively higher degree against root‐knot nematode compared to the rhizosphere colonizer (CHA0).
Pathogenicity and Vegetative Compatibility of Fusarium oxysporum f. sp. phaseoli in Greece
Authors: Elena K. , Pappas A. C.
Published: March 2003

Twenty‐seven isolates of Fusarium oxysporum (Fo) obtained from diseased beans from Greece were characterized for pathogenicity to bean cultivars and vegetative compatibility (VCG). Twenty‐three isolates were intermediate to highly virulent to five local bean cultivars and characterized as F. oxysporum f. sp. phaseoli (Fop). Zarganes, Gigantes (two selections) and Chondra were the most susceptible cultivars, while Psila was resistant to 10 of the isolates. Four Fo isolates were not pathogenic against tested cultivars. By demonstrating complementation assay, with nitrate non‐utilizing (nit) mutants, 15 pathogenic isolates were grouped into one VCG, two isolates into a previously identified VCG 0165 and six into unique unclassified VCGs. The four non‐pathogenic Fo isolates failed to anastomose with any tested pathogenic Fop strain. Our results suggest that most of Fop isolates in Greece belong to one VCG.
Post‐transcriptional Silencing of the Tomatinase Gene in Fusarium oxysporum f. sp lycopersici
Authors: Ito S. , Takahara H. , Kawaguchi T. , Tanaka S. , Kameya‐Iwaki M.
Published: March 2003

Fusarium oxysporum f. sp. lycopersici produces an extracellular enzyme tomatinase, which has been known to detoxify α‐tomatine, a preformed inhibitor of fungal growth in tomato plants. To understand the role of the tomatinase in pathogenicity, we performed transformation‐mediated disruption of the tomatinase gene in F. oxysporum f. sp. lycopersici. Mutants obtained showed increase in sensitivity to α‐tomatine and decrease in tomatinase activity in vitro. Inoculation assay showed reduced pathogenicity of the mutants on tomato plants, suggesting an important role of tomatinase in pathogenicity of this fungus. However, Southern blot analysis revealed that the resident tomatinase gene of the mutants was not disrupted but the gene replacement vector was ectopically integrated into the genome of the mutants. To clarify the mechanisms involved, we examined one of the ectopic insertion mutants at both DNA and RNA levels. No methylation of the resident tomatinase gene was detected. Northern blot analysis revealed low level of the tomatinase gene expression and also the presence of antisense RNA in the ectopic mutant. Thus, post‐transcriptional gene silencing seems to be involved in the suppression of tomatinase in the ectopic mutant.
Genetic Diversity of Phytophthora infestans (Mont.) de Bary in the Eastern and Western Highlands of Uganda
Authors: Ochwo M. K. N. , Kamoun S. , Adipala E. , Rubaihayo P. R. , Lamour K. , Olanya M.
Published: March 2003

Eight isolates of Phytophthora infestans were recovered from late blight infected samples collected from the districts of Mbale and Mbarara in the Eastern and Western highlands of Uganda in 2001 and analysed using mitochondrial deoxyribonucleic acid (DNA) haplotype and Amplified Fragment Length Polymorphism (AFLP) markers. Polymerase chain reaction amplification with the P2 primer followed by digestion with MspI yielded a three‐fragment pattern characteristic of isolates belonging to the US‐1 clonal lineage; the polymorphism was confirmed by DNA sequencing. AFLP analysis yielded 60 markers, analysis of which clustered the Ugandan isolates with reference to US‐1 isolates (US930258 and US940501). These results suggest that the examined Ugandan isolates belong to the US‐1 clonage lineage.
The Distribution of Grapevine Yellows Disease Associated with the Buckland Valley Grapevine Yellows Phytoplasma
Authors: Constable F. E. , Whiting J. R. , Jones J. , Gibb K. S. , Symons R. H.
Published: March 2003

Three blocks of Chardonnay in one vineyard in the Buckland Valley of Victoria, Australia, were surveyed over 4 years for grapevine yellows disease (GYd). Buckland Valley grapevine yellows phytoplasma (BVGYp) was the only phytoplasma detected by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis in GYd affected grapevines. GYd affected many grapevines and was characterized by remission of disease, some recurrence and occurrences in previously unaffected grapevines. A regional survey of the Buckland Valley indicated that both GYd and BVGYp occurred in the same restricted grape growing area. Within this area, BVGYp was detected in two vineyards that had been established using planting material from different sources. One could therefore speculate that BVGYp was present in these grapevines as a result of aerial transmission and was not present in the original planting material.
Cowpea Root Rot Severity and Metabolic Changes in Relation to Manganese Application
Authors: Kalim S. , Luthra Y. P. , Gandhi S. K.
Published: March 2003

Severity of root rot (Rhizoctonia solani and Rhizoctonia bataticola) of cowpea (Vigna unguiculata L.) was reduced by 42.7 and 42.0%, respectively over control following the application of 10 μg/g Mn as manganese sulphate. Reduction in disease incidence was associated with increased levels of polyphenol oxidase (PPO), peroxidase (PO) and total phenols. PO activity was several times more as compared with PPO‐specific activity and increased markedly after infection either with R. solani or R. bataticola. Contrary to PPO and PO, the specific activity of catalase declined sharply. Infection also caused an increase in the content of reducing sugars, Cu, Zn and Mn but a decrease in o‐dihydric phenols, flavanols, total soluble sugars, non‐reducing sugars and Fe contents. It is suggested that Mn at the rate of 10 μg/g soil can be used to manage the root rot of cowpea.
Pathological Alterations Caused by Anoplocephala perfoliata Infection in the Ileocaecal Junction of Equids
Authors: Rodríguez‐Bertos A. , Corchero J. , Castan o M. , Pen a L. , Luzón M. , G M. , ómez‐Bautista . , Meana A.
Published: March 2003

The pathological alterations caused by Anoplocephala perfoliata in the ileocaecal junction of 28 equids slaughtered in an abattoir in Madrid (Central Spain) are described. The lesions were scored in grades based on the intensity of the damage and were related to the tapeworm number observed. The first grade (grade I) of alterations consisted of a slight enteritis associated with focal erosions observed in 43 % of parasitized animals with low parasitic burden (1–26 tapeworms). The second grade (grade II) was a focal pseudomembranous enteritis, present in the ileocaecal junctions of 36 % infected animals with moderate to high burden (23–188 tapeworms), and the third grade (grade III) was a regional necrotizing enteritis, present in the animals (21 %) with the highest burden (72–248 tapeworms). The possible role of the lesions caused by this parasite in the aetiology of colic is discussed.
The Use of Non‐Immune Plasma Powder in the Prophylaxis of Neonatal Escherichia coli Diarrhoea in Calves
Authors: Nollet H. , Laevens H. , Deprez P. , Sanchez R. , Driessche E. Van , Muylle E.
Published: March 2003

The protective use of plasma powder from cattle and swine against experimentally induced neonatal E. coli diarrhoea in colostrum‐deprived calves was examined. Diarrhoea was induced with a strain expressing F5+ fimbriae and a strain expressing F17+ fimbriae. In all groups supplemented with bovine plasma powder, diarrhoea and fever were less severe than in the control groups. For the groups infected with the F5+E. coli strain, a reduction in excretion of the challenge strain by 2–4 orders of magnitude and by 1–2 orders of magnitude was seen when supplemented with bovine plasma powder at a dose of 25 g/l milk and 10 g/l milk, respectively.

The bovine plasma powder showed also beneficial effects in the F17+ infected groups. No mortality, no septicaemia and no severe clinical signs were observed. Concerning the excretion of the E. coli F17+ strain in the faeces, no significant difference with the control group was found.

Swine plasma powder showed little beneficial effect on E. coli diarrhoea in calves in this study.
Non‐specific immunity and ketone bodies. II:In vitrostudies on adherence and superoxide anion production in ovine neutrophils
Authors: Sartorelli P. , Paltrinieri S. , Comazzi S.
Published: March 2003

The effects of the ketone bodies β‐OH‐butyrate and acetoacetate (2.4 or 4.8 mmol/l), administered singly or simultaneouslyin vitro, on adherence and superoxide anion (SO) production in ovine neutrophils were investigated by simultaneous assay in 96‐well microplates. Because the acetoacetate used was a lithium salt, the effect of 2.4 and 4.8 mmol/l lithium chloride was also tested. Neutrophils from eight non‐lactating, non‐pregnant ewes were used. SO release from neutrophils was found to be very low in basal conditions and was apparently not stimulated by contact with plastic. Administration of 10−7 mol/l phorbol myristate acetate (PMA) caused a rapid increase and release of SO production, but smaller than that induced by co‐stimulation with plastic and 10−7 mol/l PMA. LiCl (2.4 and 4.8 mmol/l) significantly increased PMA‐stimulated release, but inhibited plastic and PMA co‐stimulated SO release. Administration of 2.4 mmol/l ketone bodies inhibited plastic and PMA‐costimulated SO release, but the effect of acetoacetate could be due to the lithium component. Administration of 4.8 mmol/l ketone bodies had no effect. Adherence was significantly increased by contact with plastic, and moreover by 10−7 mol/l PMA. The effect was similar when PMA was acting alone or with plastic. Neither basal nor stimulated adherence were affected by 2.4 or 4.8 mmol/l ketone bodies. LiCl at a concentration of 4.8 mmol/l increased PMA and plastic co‐stimulated adherence. The results suggest that, in sheep, only the ketone body β‐OH butyrate at concentrations seen in mild ketosis, could decrease bactericidal activity, while adherence is not affected. In addition to other factors that could impair the efficiency of the immune system in ketotic ruminants, the reduced bactericidal activity may contribute to the higher occurrence of infectious disease in these animals.
Analgesic, Behavioural and Cardiopulmonary Effects of Epidurally Injected Medetomidine (Domitor®) in Goats
Authors: Mpanduji D. G. , Bittegeko S. B. P. , Mgasa M. N. , Batamuzi E. K.
Published: March 2003

This study was carried out in order to evaluate the analgesic, sedative, immobilizing and cardiopulmonary effects of medetomidine in goats after lumbosacral epidural injection of three (10, 20 and 30 μg/kg body weight) doses. The volume of the injection for all three medetomidine doses was 5 ml in sterile water. Seventeen clinically healthy, Small East African goats of either sex and weighing between 12 and 22 kg (mean ± SD; 14.8 ± 2.5 kg body weight) were used. The animals were randomly assigned to two groups. Seven goats were used for evaluating analgesic, behavioural and cardiopulmonary effects while 10 were used for experimental surgery. The cardiopulmonary values and rectal temperature were determined and recorded at time 0 (preinjection) and at 5, 10, 15, 20 and 30 min, and thereafter at 15‐min intervals up to 180 min after injection. Analgesia of the flank and perineum was determined at time 0 (preinjection) and at 5, 10, 15, 30, 60, 120 and 180 min using a scoring system. The spread of analgesia to the thorax, neck, forelimbs and head was also determined and recorded. The onset and duration of lateral recumbency was noted and recorded. Medetomidine at the given doses induced variable cardiopulmonary depression, which was not detrimental to the animals. All three doses (10, 20 and 30 μg/kg) of medetomidine induced adequate analgesia of the flank and perineum. Analgesia extended to the thorax, forelimbs, neck and head. The duration of lateral recumbency was 136 and 166 min for the 20 and 30 μg/kg medetomidine doses, respectively. The duration of lateral recumbency was not determined for the animal given 10 μg/kg medetomidine. Signs of sedation (lowering of the head, drooping of the lower lip, partial to complete closure of the eyes and salivation) were noted after administration of all three doses. It can be concluded from this study that all three doses induced adequate analgesia of the flank and perineum. Surgical analgesia of the flank of goats was achieved after lumbosacral epidural administration of 20 μg medetomidine/kg, diluted in 5 ml of sterile water. Surgery was not performed with the other doses (10 and 30 μg/kg) of medetomidine.
Intraperitoneal Insemination and Retrograde Sperm Transport in Dairy Cows
Authors: López‐Gatius F. , Yániz J.
Published: March 2003

To examine the efficiency of retrograde sperm transport following intraperitoneal insemination, live and dead spermatozoa were used at different concentrations, and sperm recovery from cervical mucus (0.5 ml) 2, 6, 12 and 24 h following insemination was evaluated. Forty lactating Friesian cows, in their second to fourth lactation period, were used in this experiment. Thirty‐six cows received intraperitoneally either live or dead spermatozoa. Each group of six cows received one of three total sperm numbers of 30, 45 and 90 million. Four cows were inseminated with 90 million spermatozoa into the uterus and served as a control group. All cows were inseminated towards the end of oestrus. After intrauterine insemination sperm recovery declined, but motile and/or immotile spermatozoa were recovered from all cows at any time. In cows inseminated intraperitoneally, sperm was recovered from the cervix at 6–24 h when 90 million were inseminated. A greater number of spermatozoa was recovered after dead rather than after live sperm inseminations. Only immotile, intact or broken spermatozoa and tail‐less heads were recovered after intraperitoneal insemination using either live or dead spermatozoa. No sperm was recovered for 30 and 45 million inseminations. Our results show that, following intraperitoneal insemination, there is passive sperm transport from the peritoneal cavity to the genital tract close to the time of ovulation, and suggest a higher sperm retention in the genital tract when live as opposed to dead spermatozoa are used.
Comparative Electrocardiography in Four Species of Macaws (GeneraAnodorhynchusandAra)
Authors: Casares M. , Enders F. , Montoya J. A.
Published: March 2003

Electrocardiograms (ECGs) were recorded during isoflurane anaesthesia from 52 macaws of four species of the generaAnodorhynchusandArain order to establish electrocardiographic reference values. The birds examined were clinically healthy macaws of the following species: hyacinth macaw (HM;Anodorhynchus hyacinthinus,n= 14); green‐winged macaw (GWM;Ara chloroptera,n= 11); blue‐throated macaw (BTM;Ara glaucogularis,n= 15); and red‐fronted macaw (RFM;Ara rubrogenys,n= 12). All ECGs were recorded using a paper speed of 50 mm/s and a calibration of 10 mm = 1 mV. Significant differences were determined between species for the heart rate, duration and amplitude of the P wave, amplitude of the T wave, and amplitude of the QRS complex, specially comparing the RFM to the other macaw species. No significant differences were found between two species of similar body weight: the HM and the GWM.