bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic polymorphism of the 17th exon at porcine RYR1 locus: a new variant in a local Portuguese pig breed demonstrated by SSCP analysis
Authors: Beja‐Pereira  , Bento  , Ferrand  , Brenig
Published: March 2003

Until 1991, malignant hyperthermia represented a major and important economic loss in modern pork production. It is a recessive autosomal disorder with variable expression that was not known to occur in the local pig breeds from Portugal, Alentejano and Bísaro, prior to outcrossing with commercial breeds. In swine, this disorder is due to a mutation in exon 17 of the ryanodine receptor 1 (RYR1) gene, detectable through the analysis of a restriction fragment length polymorphism. We used this technique to distinguish between resistant (NN), carrier (Nn) and susceptible (nn) genotypes, with the aim of excluding carriers from the breeding programme. We further developed a rapid screening technique on the basis of SSCP (single‐strand conformation polymorphism). Fifteen heterozygous (Nn) individuals were found in our sample of 48 individuals from Bísaro breed using both techniques. The absence of homozygous susceptible pigs suggests that the introduction of this allele into Bísaro breed has been recent. A genetically controlled breeding programme on the basis of our findings should help to secure the future of Bísaro pigs of which few individuals are known to exist. To date, only one mutation was found in the 5′ end of exon 17 of the porcine RYR1 gene. Here we present the frequencies of this mutation and describe a new mutation detected in the Alentejano breed. PCR‐SSCP analysis followed by automatic sequencing allowed the detection of this rare transition (C → T) at nucleotide 1851 of exon 17.
Reference and probability‐matching priors in Bayesian analysis of mixed linear models
Authors: Pretorius A. L. , Van Der Merwe A. J.
Published: March 2003

Determination of reasonable non‐informative priors in multiparameter problems is not easy; common non‐informative priors, such as Jeffrey's prior, can have features that have an unexpectedly dramatic effect on the posterior. In recognition of this problem Berger and Bernardo (Bayesian Statistics IV. Oxford University Press, Oxford, UK, pp. 35–70, 1992), proposed the Reference Prior approach to the development of non‐informative priors. In the present paper the reference priors of Berger and Bernardo (1992) are derived for the mixed linear model. In spite of these difficulties, there is growing evidence, mainly through examples that reference priors provide ‘sensible’ answers from a Bayesian point of view. We also examine whether the reference priors satisfy the probability‐matching criterion. The theory and results are applied to a real problem consisting of 879 weaning weight records, from the progeny of 17 sires. These important aspects are explored via Monte Carlo simulations.
The influence of supplemental alpha‐galactosidase and phytase in a vegetable ration for dogs on the digestibility of organic components and phytate phosphorus
Authors: De Smet B. , Hesta M. , Seynaeve M. , Janssens G. , Vanrolleghem P. , De Wilde R. O.
Published: March 2003

The use of dry feeds for dogs is increasing for different reasons: in comparison to wet canned feed it is easier to handle, the amount to be given is smaller and the daily cost is less. In producing a dry pellet more vegetable ingredients are used that can contain several antinutritional factors. Some of them can be eliminated by heating. Others like galactosides and phytates are heat‐resistant but can be broken down by adding the appropriate enzymes. The specific enzymes are indeed not secreted by the animal itself. In farm animals, e.g. pigs, alpha‐galactosidase has been introduced in order to enhance the energetic value of these alphagalactosides (Veldman et al. 1993). In companion animals this enzyme is more often indicated as an antiflatulence agent, because the main alpha‐galactosides present in legume seeds (stachyose, raffinose) are known as flatulence components (Fleming 1981).

These oligosaccharides do not necessarily imply an overall lower nutrient digestibility. Zuo et al. (1996) did not prove a significant difference in digestibility between conventional and low oligosaccharide soybean meal in dog rations. Others however, (Wiernusz et al. 1995) reported the highest digestibilities and the best stool quality of those rations that contained the least amount of soybean oligosaccharides.

On the other hand, phytates (phospho‐inositols) are known as complexing agents of several divalent cations (Fe, Mg, Zn, Ca) and are themselves considered as a phosphorus source, unavailable to monogastric animals. Phytase is the appropriate enzyme, which is not secreted by the animal itself, but, when added to the diet, can enhance the bio‐availability of several minerals and trace elements (Rimbach et al. 1994) by hydrolysing the phospho‐inositol molecule.

The aim of the experiment, reported here, is to investigate the influence of the addition of alpha‐galactosidase, phytase, or both to a nearly complete vegetable ration, consisting of a relatively high content of galactosides and phytates. The combination of both enzymes was carried out because Wenk et al. (1993) reported a possible interaction between a carbohydrase and a phytase enzyme in pigs.
Energy balance of conjugated linoleic acid‐treated pigs
Authors: Müller H. L. , Stangl G. I. , Kirchgessner M.
Published: March 2003

The term conjugated linoleic acid (CLA) refers to a group of linoleic acid derivatives whose conjugated double‐binding system begins at the carbon atom 8 to 11. This means that including the cis‐trans geometry, 16 isomers are possible in theory. CLA occurs primarily in lipids of ruminants because polyunsaturated fatty acids can be converted to CLA in the rumen of these animals through the action of bacterial enzymes (Kepler et al. 1966). The most widely occurring isomer is C18 : 2 c9,t11, which is present in milk and dairy products in concentrations of 0.4–1.7% (Fritsche and Steinhart 1998). But CLA was also generated in the colon of rats fed a diet containing free linoleic acid (Chin et al. 1994b). In animal experiments CLA inhibits carcinogenesis and reduces the development of arteriosclerosis (Ip et al. 1994; Belury 1995; Jahreis and Bochmann 1998), and was found to have a specific influence on body composition. In experiments with mice, pigs and chicks a negative effect of CLA on the accumulation of body fat was observed (Pariza et al. 1996; Dugan et al. 1997; Park et al. 1997; West et al. 1998). The effective dose in those experimental diets was 0.5 to 1.5% CLA. In contrast, CLA may also act as a growth factor and increased daily weight gains of rats (Chin et al. 1994a). However, in these trials on changes in body composition the feed intake was not controlled and the observed effects may be due at least partially to differences in feed intake between the control group and the CLA animals. The objective of the present study was to investigate the influence of CLA on thermogenesis and energy balance in animals with an isoenergetic feed intake by using the methodology of the calorimetric balance technique. The animals used in the model were adult sows with a nutritional status approaching equilibrium.
Gastrointestinal transit of solid radiopaque markers in large and giant breed growing dogs
Authors: Weber M. , Stambouli F. , Martin L. , Dumon H. , Biourge V. , Nguyen P.
Published: March 2003

Observations on food tolerance in dogs have shown that some breeds, especially the giant breeds, have a greater digestive sensitivity. One of the consequences common in these breeds is a higher faecal water content and a poor faecal quality. This could be explained, at least in part, by limited digestive capacity and function in giant breed dogs. In this report, the gastric emptying that represents one parameter of the digestive function was studied in large and giant breed dogs during their growth. Six Great Danes (GD) and six Giant Schnauzers (GS) were fed small radiopaque markers mixed with a test diet at 12, 22 and 36 weeks of age. Abdominal radiographs were made every 30 min for a period of 4 h and then hourly until 12 h. At 12 weeks of age, the gastric emptying pattern was similar in both breeds. However, from 22 weeks of age, the gastric emptying of the GD was significantly more rapid than that of GS. The gastric emptying of small markers tended to slow down in growing dogs, especially in GS. A significant positive correlation between the gastric emptying time of 50% of markers and the body weight was found. These results show that GD have a lower gastric retention time of foods, which could lead to a poor digestion and an altered absorption of nutrients. These could explained why digestive function and sensitivity could be different in dogs from different sizes and breeds.
Influence of the probiotic strain Bacillus cereus var. toyoi on the development of enterobacterial growth and on selected parameters of bacterial metabolism in digesta samples of piglets
Authors: JADAMUS A. , VAHJEN W. , SCHÄFER K. , SIMON O.
Published: March 2003

The effect of the probiotic strain Bacillus cereus var. toyoi on enterobacterial growth and selected metabolic parameters in digesta samples from piglets before and shortly after weaning was studied. Growth capacities of enterobacteria in digesta samples were significantly reduced, but no correlation was found between enterobacterial growth and concentrations of short‐chain fatty acids and lactic acid, which are often influenced by other probiotic preparations. Tendencies for higher amounts of short‐chain fatty acids were only recorded in digesta samples from the end of the jejunum, caecum and colon from piglets receiving probiotic‐supplemented feed. Lactic acid concentrations were reduced by the presence of B. cereus var. toyoi in feed in the first segment of the jejunum during the suckling period, while samples of the lower parts displayed an increased amount 4 days after weaning. Microbial activity of taurocholine deconjugating enzymes was significantly reduced in jejunum digesta from probiotic‐fed piglets. There are strong indications that the early uptake of already modified microbial populations from faeces of the mother sow aids modification of intestinal microbial communities and their metabolic activities in piglets.
The assessment of the frequency of chews during rumination enables an estimation of rumination activity in hay‐fed sheep
Authors: KASKE M. , BEYERBACH M. , HAILU Y. , GÖBEL W. , WAGNER S.
Published: March 2003

The objective was to assess rumination behaviour and, more specifically, the intra‐individual and inter‐individual variation of the frequency of chews during rumination (per min) in five Blackhead sheep fed hay at a level of 100% maintenance (experimental period [EP] I), 50% maintenance (EP II) and ad libitum (EP III). Animals ruminated in EP II less (416 min/day) than in EP I and III (558 and 592 min/day, respectively). Mean inter‐individual coefficents of variation (CV) of frequency (defined as number of chews/duration of chewing per cycle) were 12.5%, mean intra‐individual CV were 2.5%. The respective CVs for the duration of rumination per day were 8.1 and 9.7%, respectively. The level of intake influenced the frequency of chews significantly. It is concluded that the frequency of chews has to be considered in studies investigating chewing behaviour of ruminants. Under the experimental conditions investigated, number of chews during rumination per day could be estimated by the frequency of chewing with nearly the same precision as by using the duration of rumination per day.
Plasma lipid concentrations, macronutrient digestibility and mineral absorption in dogs fed a dry food containing medium‐chain triglycerides
Authors: Beynen A. C. , Kappert H. J. , Lemmens A. G. , Van Dongen A. M.
Published: March 2003

In a cross‐over trial with feeding periods of 2 weeks, six healthy dogs were fed a dry food with a total fat content of 13.4% and containing either 5% (w/w) corn oil (11% of dietary metabolizable energy) or an isoenergetic amount of medium‐chain triglycerides (MCT). The two diets were supplied on a restricted basis. There were no food refusals and no diet difference in palatability was observed. The MCT vs. Corn oil did not significantly influence plasma lipid concentrations, but group mean triacylglycerol concentrations were increased by 23% (p=0.074). The MCT consumption did not affect the apparent digestibilities of crude protein and soluble carbohydrates and had no impact on the absorption of calcium, magnesium and phosphorus. The incorporation of MCT into the diet produced a slight increase (by 0.9 percentage units) in crude fat digestibility (p=0.061). It is concluded that MCT at the present inclusion level may not have disadvantageous effects.
Is the common sowthistle (Sonchus oleraceus) a primary host plant of the cotton bollworm, Helicoverpa armigera (Lep., Noctuidae)? Oviposition and larval performance
Authors: Gu H. , Walter G. H.
Published: March 2003

Helicoverpa armigera (Hübner) is a polyphagous pest that has a relatively strong affinity in the field for the European weed Sonchus oleraceus L. in parts of Australia. The oviposition preference of H. armigera was examined in relation to sowthistle and some crop hosts on which it is a pest. In a group test with simultaneous exposure of moths to common sowthistle, maize, sorghum and two cotton cultivars, H. armigera females consistently showed strongest affinities for common sowthistle, irrespective of moth age or the original host of the test insects in the field. Females (n = 20) exposed individually to a choice between common sothistle and cotton, varied substantially in preference. Among the females tested, 67% showed a stronger affinity for common sowthistle, about 5% preferred cotton and 28% did not discriminate. Common sowthistle was also the most preferred by newly hatched larvae among the five host plant types presented in a multiple choice test. Larvae fed on common sowthistle flowers had a higher survival rate and body weight than those fed on cotton flowers. These results and previous field observations suggest that S. oleraceus may be a primary host plant (or one of the primary host species) to which H. armigera became adapted at the time of speciation.
Growth and induction in food consumption of Helicoverpa armigera Hbn. (Lep., Noctuidae) larvae on chickpea, soybean, and maize diets
Authors: Singh A. K.
Published: March 2003

Laboratory studies were conducted to determine the effect of different artificial diets made of powdered seed materials of chickpea (Cicer arietinum), soybean (Glycine max), and maize (Zea mays) on the growth, consumption, and feeding preferences of Helicoverpa armigera larvae. Food consumption and growth of ultimate instar gram pod borer larvae were minimal on maize diet. The nutritive value of the soybean diet was higher, but the consumption rate of larvae was highest on chickpea diet compared with the other test diets. The growth of larvae was statistically equal on chickpea and soybean diets, in spite of differences in the consumption rate of these diets and their nutritive value. There appears to be a direct correlation between the quantity of the diets consumed and their nutritive value for growth of the larvae on chickpea and soybean diets. The lower nutritive value of chickpea diet is correlated with its higher intake by the larvae. Similarly, the lower consumption rate of larvae on soybean diet is correlated with its higher nutritive value. The diet on which the larvae were fed during earlier instars did not induce any feeding preference for that particular diet in the ultimate larval instar. The larvae consumed similar quantities of each of the three diets in their ultimate instar, irrespective of having fed on any of these diets during any preceding instars. However, induction in the quantitative consumption of food by the larvae was evident. The higher or lower consumption rate of diet by the larvae in the ultimate instar was influenced by their food during earlier instars. Hence the food consumption rate of larvae in the last instar appears to be set while feeding on a diet in the preceding instars.
A simplified method for screening acetylcholinesterase inhibitors by the flesh fly (Dipt., Sarcophagidae) cell culture system
Authors: Ohashi A. , Mitsuhashi J. , Sato K.
Published: March 2003

A simplified economical method for assaying acetylcholinesterase inhibitors was devised. A flesh fly, Sarcophaga peregrina Robineau‐Desvoidy, cell line, NIH‐SaPe‐4, was cultured in 96‐well microplates at 25°C. After 2 days culture, the culture media was removed and phosphate buffer was introduced. The cells were disintegrated by freezing–thawing, and a reaction mixture containing substrate, inhibitor, and colour developer was added. The change of absorbance at 405 nm at 25°C was measured with a microplate photometer and the concentration of the test substance required to inhibit the enzyme reaction by 50% (I50) was calculated.
Small‐scale production of the common green lacewing Chrysoperla carnea (Stephens) (Neuropt., Chrysopidae): minimizing costs and maximizing output
Authors: McEwen P. K. , Kidd N. A. C. , Bailey E. , Eccleston L.
Published: March 2003

This paper outlines a system for the production of common green lacewings in the laboratory, using easily available and inexpensive equipment and producing a healthy surplus of insects for experimental purposes. An economic breakdown of costs is given.
Potential of the entomopathogenic fungus, Beauveria bassiana strain CS‐1 as a biological control agent of Plutella xylostella (Lep.,Yponomeutidae)
Authors: Yoon C. ‐S. , Sung G. ‐H. , Park H. ‐S. , Lee S. ‐G. , Lee J. ‐O.
Published: March 2003

Laboratory and net house assays of the entomopathogenic fungus, Beauveria bassiana CS‐1, were conducted to examine the possibility of using this strain to control the diamondback moth (DBM), Plutella xylostella in Korea. Treatment of conidial suspensions at various concentrations indicated that corrected mortality at 1 × 108 conidia/ml was 86.23% with LT50 of 1.63 days under the laboratory conditions and 66.5% with LT50 of 3.61 days in the net house assay. Assessment of rigorous dose–response showed that at least 1800 conidia of the strain CS‐1 should adhere to a single DBM larva to induce successful infection. These results indicated that the strain CS‐1 has the capability to lower the DBM larval population rapidly as well as effectively.
Progression in field infestation is linked with trapping of coffee berry borer, Hypothenemus hampei (Col., Scolytidae)
Authors: Mathieu F. , Brun L. O. , Frerot B. , Suckling D. M. , Frampton C.
Published: March 2003

Phenology of the coffee plant and infestation by coffee berry borer Hypothenemus hampei Ferrari were studied in relation to trapping of adult females in kairomone‐baited traps in a coffee plantation in New Caledonia. In a 0.4 ha coffee field, a group of 27 trees located along a transect beginning at an early infestation point was selected. The number of green, red and dry coffee berries, along with the number of larvae, adult males and females per berry was determined monthly from October 1993 to July 1994. Twelve, red multifunnel traps, each baited with a solution of methanol:ethanol (1:1 ratio, a mean solution release rate of 1 g/day) were placed within the coffee field, along the transect, within the selected trees, grouped in four zones named 1–4. Two additional traps were located outside the plantation.

The proportion of infested berries increased as berry maturity and harvest date approached, while the infestation rate decreased with distance from the epicentre. Over the 10 months of the study, beetle populations increased and spread from the original infestation point across the different zones, according to distance and availability of berries or appropriate physiological status. Traps near the epicentre caught the largest numbers of beetles. Linear relationship between trap catch and infestation level was demonstrated. Traps placed outside the field approached zero catch. Trap catch was highly influenced by rainfall events, and the highest captures coincided with rapidly declining berry numbers on trees. There are good prospects for management of this insect using traps.
Effect of temperature on the susceptibility of Culiseta longiareolata (Macquart) (Dipt., Culicidae) to two standard strains of biocontrol bacteria
Authors: Katbeh‐Bader A. , Khyami‐Horani H. , Mohsen Z. H.
Published: March 2003

The susceptibility of fourth instar larvae of Culiseta longiareolata (Macq.) to two standard strains of biocontrol bacteria was investigated under laboratory conditions. Larvae were found to be more susceptible to Bacillus sphaericus (Bs‐IPS88) than to Bacillus thuringiensis H14 (Bti‐IPS82) at 25 ± 1°C at concentrations ranging from 0.003 to 0.004 ppm at 2 and 3 days post‐treatment. Statistical regression analysis revealed a significant mortality–concentration relationship for the two bacteria. Larval mortality increased significantly as temperature increased from 20 ± 1°C to 28 ± 1°C.
Effect of cropping season and possible compounds involved in the resistance of Lycopersicon hirsutum f. typicum to Tuta absoluta (Meyrick) (Lep., Gelechiidae)
Authors: Ecole  , Picanço  , Guedes  , Brommonschenkel
Published: March 2003

The effect of cropping season on the resistance of the accession LA 1777 of Lycopersicon hirsutum f. typicum to the tomato leafminer Tuta absoluta (Meyrick) and the preliminary identification of the possible compounds involved in this trait were the objectives of this study. Two experiments were carried out with the accession LA1777 and the commercial cultivar Santa Clara of Lycopersicon esculentum. The first experiment was carried out during the summer season (January to April 1997) and the second was carried out during the autumn–winter season (May to September 1997). The accession LA 1777 was significantly more resistant to T. absoluta than the commercial cultivar, especially during the autumn–winter cropping season. Either antibiosis or antixenosis was probably responsible for the higher larvae mortality (54.2 and 91.2% for the summer and autumn–winter seasons, respectively) and longer larval development of T. absoluta (14.2 and 25.9 days for summer and autumn–winter seasons, respectively) on L. hirsutum f. typicum as compared with L. esculentum (11.0 and 19.6 days for summer and autumn–winter seasons, respectively). Insect fecundity parameters such as oviposition period, number of eggs/female, and rate of larvae eclosion were also negatively affected by L. hirsutum f. typicum. Fourteen main peaks were observed in total ion chromatograms of both tomato species. Eleven of these were present only in chromatograms of the accession, one was only present in chromatograms of the commercial cultivar, and two peaks were present in chromatograms from both when hexane extracts of leaves were subjected to a gas chromatographic–mass spectrometric analysis (GC–MS). However, the matches obtained between the peak spectra and the MS database were too low to justify even preliminary identification of the compounds.
Sujiol, a new potent insect growth regulator from Juniperus communis L. against last instar larvae of Spodoptera litura
Authors: Vardhini D. , Raja S. S. , Varalakshmi K. , Quddus K. M. A.
Published: March 2003

Sujiol, a terpenoid isolated from the berries of Juniperus communis, exhibited growth regulating activity in the last instar larvae of Spodoptera litura. The larvae were treated with 0.1, 0.25, 0.5, 0.75, 1, 2 and 4% concentrations of Sujiol, in solvent acetone. Formation of non‐viable adults, interference in ecdysis and development of mosaics were the important morphogenetic peculiarities observed. The resultant forms were ruled out from further development and reproduction.
A juvenile hormone analogue with potential for termite control: laboratory tests with Reticulitermes santonensis, Reticulitermes flaviceps and Coptotermes formosanus (Isopt., Rhinotermitidae)
Authors: Hrdý I. , Kuldová J. , Wimmer Z.
Published: March 2003

Laboratory experiments with three species of termites were conducted to study the efficacy of a carbamate derivative of 2‐(4‐hydroxybenzyl)‐1‐cyclohexanone (W‐328). The compound has been found to be highly active causing differentiation of termite workers into presoldiers, soldiers and/or soldier‐intercastes. Differentiation of excessive soldiers induced by juvenile hormone analogues (JHAs) may disrupt the social homeostasis and consequently cause death of the whole termite colony. W‐328 induced differentiation into soldiers in 41–100% of individuals when applied in range of 50–500 ppm to a feeding substrate of wood in force‐feeding and choice bioassays with groups of Reticulitermes santonensis Feytaud and R. flaviceps (Oshima). Efficacy of W‐328 was also confirmed in choice bioassays with isolated groups of workers and soldiers and with incipient colonies of Coptotermes formosanus Shiraki. A high proportion of JHA‐induced differentiation into soldier caste was accompanied by increased mortality. Termites accept a matrix treated with W‐328 quite well. Significant feeding deterrence of the compound was observed only at higher concentrations: 500 ppm in some tests with Reticulitermes spp. and 5000 ppm in colonies of C. formosanus. Adequate persistence of W‐328 in corrugated cardboard (a potential feeding substrate for baits) was confirmed by bioassay with R. santonensis and by chemical analysis. The residue levels of the compound, applied at 500 ppm concentration, after 27 days of conditioning remain high enough to result in significant soldier differentiation.
Impact of antennectomy, eye blinding and tibial comb coating on the predatory behaviour of Rhynocoris kumarii Ambrose and Livingstone (Het., Reduviidae) on Spodoptera litura Fabr. (Lep., Noctuidae)
Authors: Claver M. A. , Ambrose D. P.
Published: March 2003

The predaceous reduviid Rhynocoris kumarii uses its antennae, eyes and tibial comb to predate tobacco cutworm Spodoptera litura (Fabr). A delayed arousal response was observed in the antennectomized, eye blinded and tibial comb‐coated predators. The predators whose entire antennae had been removed showed significant delayed approach but the approach response was not affected significantly in the blinded and tibial comb‐coated reduviid predators. Capturing response was significantly affected in pedicel and entire antennae‐removed predators, and blinded and tibial comb‐coated predators. Antennectomy, eye blinding and tibial comb coating did not cause any impact in the act of paralysing the prey. Progressive reduction in sucking duration and the number of sucking sites were observed as a function of sequential segment‐wise removal of antennae. A reduction in the sucking duration and number of sucking sites were also observed in blinded and tibial comb coated predators.
Regulation of digestive proteolytic activity in the larvae of Spilosoma obliqua (Lep., Arctiidae)
Authors: Anwar A. , Saleemuddin M.
Published: March 2003

Proteolytic activity from the guts of the lepidopteran larvae Spilosoma obliqua was studied in relation to the developmental stages. The activity was found to increase with the advancement in the age of larvae and decreased with the onset of pupation. Starvation of fifth instar larvae, which exhibited maximum proteolytic activity, led to an increase at 8 h and declined further. There seems to be a possible relationship between the availability of the food and secretion of the enzymatic activity. The optimum pH and temperature for the gut protease was 11.0 and 50°C, respectively. Incubation of the gut protease for 24 h at 37°C led to a decrease in 52% of the activity, whereas there was a decrease of 17% in the activity at 4°C. No evidence could be found for the existence of the protease as an inactive precursor. The alkaline properties of the digestive protease seem to have all the potential to be exploited commercially as a additive in various biological formulations.
Evaluation of Ssp I polymerase chain reaction assay in the detection of Wuchereria bancrofti infection in field‐collected Culex quinquefasciatus and its application in the transmission studies of lymphatic filariasis
Authors: Hoti S. L. , Patra K. P. , Vasuki V. , Lizotte M. W. , Hariths V. R. , Sushma N. , Gunasekaran K. , Ramaiah K. D. , Vanamail P. , Mariappan T. , Williams S. A.
Published: March 2003

Abstract: Ssp I polymerase chain reaction (PCR) assay, developed for Wuchereria bancrofti, was evaluated for its sensitivity in detecting infection in the vector, Culex quinquefasciatus, in the field. The evaluation of the assay was carried out using pools of vector mosquitoes collected from areas under filariasis survey and control trial projects, in comparison with the standard dissection and microscopy technique. In the filariasis survey area the infection rate as determined by the dissection and microscopy technique was 0.89% whereas it was 1.7% by PCR assay. In the Bacillus sphaericus trial area the infection rates as assessed by the conventional technique were 6.6 and 4.5% in the treated and check areas, respectively, whereas those obtained by the PCR assay were 4.7 to 2.2%. Although the infection rates determined by the PCR assay are slightly higher or lower than the rates obtained by the conventional technique, the difference was not statistically significant (P=0.451 for filariasis survey area, and P=0.203 and 0.161 for B. sphaericus trial area). When the pool size of Cx. quinquefasciatus was increased to 50 the sensitivity of the PCR was affected. The changes in infection rates as influenced by the antifilarial chemotherapy were similar when determined by PCR assay and the standard method. The major advantage of the PCR assay over the conventional technique is that thousands of mosquitoes can be processed within a short duration and this attribute has potential application in rapid assessment of disease prevalence and monitoring of the transmission dynamics.
Microcosm studies on intraguild predation between female erigonid spiders and lacewing larvae and influence of single versus multiple predators on cereal aphids
Authors: Dinter A.
Published: March 2003

Abstract:  Intraguild predation between female erigonid spiders [Erigone atra (Blackwall) and Oedothorax apicatus (Blackwall), Araneae, Erigonidae] and lacewing larvae (second instar larvae of Chrysoperla carnea (Stephens), Neuropt., Chrysopidae) and interaction effects of predator combinations on cereal aphids were investigated in a microcosm system under laboratory conditions. The microcosm experiments were run for 7 days and consisted of 15wheat seedlings, 15 Sitobion avenae (F) (Hom., Aphididae) as start population, plus a female spider or a lacewing larva or a combination of a spider plus a lacewing larva. The mortality rate of lacewing larvae was significantly increased by 44 and 31% due to intraguild predation by female spiders of E. atra and O. apicatus in comparison with lacewing larvae that were kept alone. The final aphid numbers in the microcosms were significantly reduced by all single predator treatments (spiders, lacewing larvae) and the predator combinations in comparison with controls without predators. The predation effect on aphid populations due to both spider species was similar and not statistically different. An additive effect of the predator combinations ‘spider plus surviving lacewing larva’ was found for both spider species resulting in reduced aphid numbers compared with the single predator treatments. When the lacewing larva was killed by an E. atra female the effects on aphids were non‐additive, but aphid numbers were not statistically increased compared with the lacewing larva treatment. When the lacewing larva was killed by an O. apicatus female, the effects of spider and C. carnea larva were additive on aphid numbers. In the presence of additional prey (fruit flies and Collembola) intraguild predation was not found and E. atra females had no significant effect on the survival of lacewing larvae. In addition, E. atra females had no significant effect on aphid numbers in the presence of fruit flies and Collembola, but in combination with a lacewing larva that survived, a significantly greater reduction of the aphid population was observed compared with the lacewing larva treatment. The body mass of lacewing larvae at the end of the experiment was not statistically influenced by the presence or absence of an E. atra female.
Insect pests and natural enemies in two varieties of quinua (Chenopodium quinoa) at Cusco, Peru
Authors: Yábar E. , Gianoli E. , Echegaray E. R.
Published: March 2003

Abstract:  The abundance of insect pests and natural enemies in two varieties of quinua, Chenopodium quinoa (Blanca de Junín and Amarilla de Maranganí) throughout the growing season in the Southern Peruvian Andes is described. The quinua varieties differ, among other traits, in their content of saponins (secondary metabolites associated to plant resistance) late in the season. Whereas Agromyzidae and Cicadellidae were abundant only in the early season, both Chrysomelidae and Aphididae populations showed fluctuations. Likewise, Araneae and Braconidae showed fluctuating numbers during the season. The abundance of Coccinellidae peaked at mid‐season whereas that of Syrphidae was high only in the late season. Although the overall abundance of insects was very similar in both varieties of quinua, there were different patterns depending on the season. In the early season there was a tendency towards greater insect numbers on Blanca, but in contrast, in the late season Amarilla (the high‐saponin variety) had a higher load of insect pests. This suggests that saponins do not play a major role in quinua resistance against insects. In the early season, no significant relationship between pests and natural enemies held across quinua varieties. In the late season, Aphididae and Coccinellidae were negatively and significantly correlated in both varieties. The temporal population dynamics of Aphididae and both Coccinellidae and Braconidae resembled the traditional predator–prey dynamics.
Reproduction of the ambrosia beetle, Xyleborus pfeili (Ratzeburg) (Col., Scolytidae), on semi‐artificial diet
Authors: Mizuno T. , Kajimura H.
Published: March 2003

Abstract: Reproduction of the ambrosia beetle Xyleborus pfeili (Ratzeburg), in relation to galley formation, was examined by artificial rearing in test tubes. Unmated females produced only male offspring, while broods that originated from fertilized females had strongly female‐biased sex ratios. Thus, the reproductive process of X. pfeili is arrhenotokous parthenogenesis. Oviposition took place over a long time, as eggs were present in the tunnels throughout the experiments (up to 40 days after inoculation). Total length of a gallery system and number of offspring per tube were positively correlated. Pupation and eclosion of males were later than those of some females. In the case of two males (offspring in pupal and/or adult stages) in the same gallery system, most of the males coexisted in the condition of both different stages and different branch tunnels. These results imply that a mother beetle of X. pfeili determines the number of her eggs in response to the size of each branch tunnel (= amount of ambrosia fungus), and produces at least one male egg in the tunnel after laying some female eggs.
Scab Response of Selected Winter Wheat Cultivars after Inoculation with Fusarium avenaceum (Fr.) Sacc.
Authors: Goliński P. , Kiecana I. , Kaczmarek Z. , Kostecki M. , Kaptur P. , Wiśniewska H. , Chełkowski J.
Published: March 2003

Inoculation experiments with 10 winter wheat cultivars were performed in two different regions of Poland, which have different climates, located at Cerekwica (Central‐west) and Sitaniec (South‐east part of Poland), in the seasons of 1995 and 1996, and Fusarium avenaceum isolate KF 203 (ATCC 64451) (producing moniliformin) was used in inoculation of winter wheat heads. The percentage of scabby kernels was changeable during the experiment, although no interaction environment × cultivar was observed. Yield traits confirm that the climatic conditions in Sitaniec are favourable for higher scab incidence, and indicate that cultivar Aleta was (at both locations) the most resistant to the disease. Reduction of all yield traits for all the cultivars, at two locations, during two vegetative seasons, indicates that cvs Aleta, Almari and Begra were of the lowest susceptibility to scab, whereas Rosa and Parada were the most susceptible to the disease. Accumulation of moniliformin in kernels on average in Sitaniec was 2.28 μg/g during 1995 and 0.41 μg/g in 1996, and in Cerekwica it was 2.12 and 1.77 μg/g in 1995 and 1996, respectively. The results of chemical analysis confirm low susceptibility of cultivar Aleta to scab.
International Rice Research Institute, Los Baños, Philippines
Authors: Cruz F. C. StA. , Boulton M. I. , Hull R. , Azzam O.
Published: March 2003

A system for agroinoculating rice tungro bacilliform virus (RTBV), one of the two viruses of the rice tungro disease complex, has been optimised. A nontumour‐inducing strain of Agrobacterium (pGV3850) was used in order to conform with biosafety regulations. Fourteen‐day‐old seedlings survived the mechanical damage of the technique and were still young enough to support virus replication. The level of the bacterial inoculum was important to obtain maximum infection, with a high inoculum level (0.5 × 1012 cells/ml) resulting in up to 100% infection of a susceptible variety that was comparable with infection by insect transmission. Agroinoculation with RTBV was successful for all three rice cultivarss tested; TN1 (tungro susceptible), Balimau Putih (tungro tolerant), and IR26 (RTSV and vector resistant). Agroinoculation enables resistance to RTBV to be distinguished from resistance to the leafhopper vector of the virus, and should prove useful in screening rice germplasm, breeding materials, and transgenic rice lines.
Vegetative Compatibility Grouping of Colletotrichum kahawae in Kenya
Authors: Gichuru E. K. , Várzea V. M. P. , Rodrigues C.J. , Masaba D. M.
Published: March 2003

Vegetative compatibility using nitrate nonutilizing (nit) mutants was analysed between 44 isolates of Colletotrichum kahawae from Kenya, one each from Ethiopia and Malawi, one of Colletotrichum gloeosporioides and one of Colletotrichum acutatum. Another isolate of C. kahawae did not generate mutants and thus could not be utilized. The results showed that all the C. kahawae isolates, except a white sector mutant (VCG2), belonged to one vegetative compatibility group (VCG4). The other species belonged to their own unique groups (VCGs 1 and 3). Implications of the results and future research needs on the subject are discussed.
Characterization of Trichoderma Isolates from Philippine Rice Fields by UP‐PCR and rDNA‐ITS1 Analysis: Identification of UP‐PCR Markers
Authors: Cumagun C. J. R. , Hockenhull J. , Lübeck M.
Published: March 2003

Forty‐two isolates of Trichoderma from rice fields in four provinces in the Philippines were characterized using rDNA‐ITS1 analysis and universally primed polymerase chain reaction (UP‐PCR). Two groups were clearly distinguishable on the basis of length and restriction pattern of the internal transcribed spacer (ITS) region of the ribosomal DNA and UP‐PCR banding profiles using UP primer, L45. The 40 isolates comprising the largest group were very similar with respect to their UP‐PCR banding profiles and were assigned to Trichoderma harzianum Rifai following morphological identification of four of the isolates. The two isolates belonging to the second group were identified as Trichodermaviride Pers. ex. Gray on the basis of their morphology, rDNA‐ITS1 analysis and distinct UP‐PCR banding profiles. One of the T. harzianum isolates with good cellulolytic and competitive saprophytic abilities was analysed using single and pair‐wise combinations of UP primers in order to distinguish it from the remaining 41 isolates. A suitable diagnostic marker was identified and this marker will be valuable for monitoring the isolate in field tests.
Comparisons of Isolates of Fusarium avenaceum from White Lupin and Other Crops by Pathogenicity Tests, DNA Analyses and Vegetative Compatibility Tests
Authors: Satyaprasad K. , Bateman G. L. , Ward E.
Published: March 2003

Isolates of Fusarium avenaceum, mostly from crops of white lupin or wheat, were tested for pathogenicity on white lupin and wheat plants and compared by DNA tests and, in a limited study, vegetative compatibility. Most of the 80 isolates were pathogenic on both plant species after inoculation on shoot bases. Disease severity was greater at higher incubation temperatures that ranged from 15/10°C to 25/20°C (day/night temperatures). Isolates from lupin crops tended to be more pathogenic, on average, on lupins than on cereals. Polymerase chain reaction (PCR)‐restriction fragment length polymorphism (RFLP) analysis of the internal transcribed spacer region of the rDNA distinguished two groups of isolates that occurred in different proportions among isolates from lupins and cereal crops. Random amplified polymorphic DNA (RAPD)‐PCR analyses indicated considerable genetic variation among isolates, but there was some similarity among groups of isolates from populations in the same field. Genetic diversity was confirmed by a high degree of vegetative incompatibility among 20 isolates using nitrate nonutilizing mutants. There were no relationships among pathogenicity, RFLP group, RAPD group and vegetative compatibility group.
Differential Growth Inhibition of Diaporthe and Phomopsis Isolates by the Metabolic Activity of Five Actinomycetes
Authors: Munta ñola‐Cvetkovic M. , Vukojevic J. , Mihaljcevic M.
Published: March 2003

Fifty‐five cultures derived from Diaporthe perithecia and Phomopsis pycnidia found on diverse host plant species collected at different times and sites in Vojvodina, Yugoslavia, showed distinguishing quantitative reactions to the fungistatic activity of five actinomycetes obtained as fortuitous laboratory contaminants coming from field material. Streptomyces albidoflavus, S. albus, S. diastaticus, Streptomyces sp., and Streptoverticillium sp. could be ranked by their growth‐inhibitory potential, with S. albus showing the strongest, and Streptomyces sp. the lowest. The responses of the fungi varied depending on the tested actinomycetes, but two major groups could be distinguished: A, which encompased the isolates that were less affected by the proximity of the actinomycetes; and B, with those which exhibited high sensitivity in all the experiments. Group A was typically represented by Diaporthe arctii, Phomopsis longicolla, and the Phomopsis type‐1 cultures from Xanthiumitalicum; group B was typically represented by Diaporthe/Phomopsis helianthi,Phomopsis type‐2 cultures from X. italicum, and isolates from Lactuca serriola. The results obtained underscore the dissimilarities between D. arctii and D. helianthi, and corroborate the value of the physiological aspects of congeneric isolates in considering taxonomic problems in the coelomicete genus Phomopsis.
Time‐Dependent Sporulation, Conidial Size and Germ Tube Formation in Alternaria tenuissima (Kunze ex Pers.) Wiltshire on Different Media
Authors: Singh U. P. , Sarma S. K. Singh B. K.
Published: March 2003

Time‐dependent sporulation, conidial size and germ tube formation in Alternaria tenuissima (Kunze ex Pers.) Wiltshire on different media were studied. The results indicate that maximum number of first spore was formed on potato dextrose agar (PDA) and new leaf extract of pigeon pea followed by old leaf extract of pigeon pea and distilled water (DW). The sporulation was relatively poor on other media. The maximum number of spores in a chain were produced on PDA and albumen +0.9% sodium citrate. Only one spore was seen in DW. According to time‐dependent sporulation, the media were divided into three categories: on some media the first spore was formed in 18 h, in another group it took 30–36 h and in the third group the first conidium was formed after 40 h. Four germ tubes were commonly formed on most of the media. The largest conidia were observed on potato dextrose and the smallest ones were seen on DW.
Detection of Phytoplasma Infection in Rose, with Degeneration Symptoms
Authors: Kamińska M. , Dziekanowska D. , Rudzińska‐Langwald A.
Published: March 2003

In 1998 a severe disease was observed on rose cvs. ‘Patina’, ‘Papillon’ and ‘Mercedes’ cultivated in a commercial greenhouse in Poland. The symptoms included stunted growth, bud proliferation, leaf malformation and deficiency of flower buds. Sporadically some plants yielded flower buds transformed into big‐bud structures and degenerated flowers. The presence of phytoplasma in roses with severe symptoms as well as in recovered plants and Catharanthus roseus experimentally infected by grafting and via dodder was demonstrated by nested polymerase chain reaction assay with primers pair R16F2/R2 or R16F1/R0 and R16(I)F1/R1 amplifying phytoplasma 16S rDNA fragment. The polymerase chain reaction products (1.1 kb) used for restriction fragment length polymorphism analysis after digestion with endonuclease enzymes AluI and MseI produced the same restriction profiles for all samples. The restriction profiles of phytoplasma DNA from these plants corresponded to those of an aster yellows phytoplasma reference strain. Electron microscope examination of the ultra‐thin sections of the stem showed wall thickenings of many sieve tubes of the diseased roses and single phytoplasma cells within a sieve element of the phloem of experimentally infected periwinkles. This paper is the first report on aster yellows phytoplasma in rose identified at a molecular level.
Infection Structures and Localization of the Pathogenesis‐related Protein AP24 in Leaves of Tomato Plants Exhibiting Systemic Acquired Resistance against Phytophthora infestans after Pre‐treatment with 3‐Aminobutyric acid or Tobacco Necrosis Virus
Authors: Jeun  , Buchenauer
Published: March 2003

In tomato plants systemic acquired resistance (SAR) against late blight caused by Phytophthora infestans was induced by pre‐treatment with a chemical inducer, DL‐3‐aminobutyric acid (3‐ABA), or by pre‐inoculation with a biotic inducer, Tobacco necrosis virus (TNV). Ultrastructural studies revealed that haustoria of the late blight fungus in tomato leaves expressing SAR were morphologically changed and some of them were severely damaged. Both inducers eventually caused a significant inhibition of haustorium development and hyphal growth. To investigate the possible role of pathogenesis‐related proteins (PR‐proteins) in the defence of leaves of tomato plants expressing SAR, the accumulation and localization of the tomato PR‐protein AP24 were studied by immunocytochemical methods. Immunofluorescence labelling investigations demonstrated a systemic accumulation of AP24 in leaves of tomato plants either pre‐treated with 3‐ABA or pre‐inoculated with TNV. In the corresponding leaves of control plants without SAR induction this protein was accumulated only after inoculation with P. infestans. Furthermore, AP24 became detectable by immunogold labelling in starch granules of chloroplasts of untreated upper leaves expressing SAR. After invasion of the late blight fungus, AP24 was also detected in fungal cell walls and the space formed between fungal cell walls and the invaginated plasma membrane. A more dense accumulation of AP24 was observed in fungal cell walls as well as in cell wall appositions (papillae) in leaves expressing SAR. These findings indicate that pre‐treatment with the chemical inducers 3‐ABA and pre‐inoculation with the biotic inducer TNV activated a similar accumulation pattern of AP24 in leaves of tomato plants exhibiting SAR.