Cucullanus oceaniensis sp. n. (Nematoda: Cucullanidae) from Pacific eels (Anguilla spp.)

A new species of parasitic nematode, Cucullanus oceaniensis sp. n., is described from the intestine of the giant mottled eel Anguilla marmorata (type host) from Futuna Island (Wallis and Futuna Islands, Polynesia) and from A. marmorata and Anguilla sp. (cf. obscura) from Fiji Islands (Melanesia, South Pacific). The main distinguishing characteristics are the length of spicules (668-1,020 microm), situation of deirids (slightly anterior to the oesophago-intestinal junction) and the excretory pore (some distance posterior to the end of oesophagus), and the arrangement of caudal papillae in the male. It is the third known species of Cucullanus from Oceania and the first one reported from freshwater eels in the region of South Pacific. Cucullanus faliexae Morand et Rigby, 1998 is considered a junior synonym of Cucullanus australiensis Baylis, 1927.     

Molecular aspects of the potato — Phytophthora infestans interaction

The fungal pathogenPhytophthora infestans is the causal organism of late blight, one of the most devastating diseases of potato. In the past, various aspects of the potato-P. infestans interaction have been studied extensively. In this paper we briefly review the current knowledge of the molecular events associated with the interaction and in addition we discuss a new approach for analyzing the molecular basis of pathogenicity ofP. infestans.     

Acquired resistance triggered by elicitins in tobacco and other plants

Elicitins are a family of proteins excreted byPhytophthora spp. They exhibit high sequence homology but large net charge differences. They induce necrosis in tobacco plants which then become resistant to the tobacco pathogenPhytophthora parasitica var.nicotianae. In stem-treated plants, resistance was not restricted to the site of elicitin application, but could be demonstrated by petiole inoculation at all levels on the stem. Resistance was already maximum after two days and lasted for at least two weeks. It was effective not only towardsP. p. var.nicotianae infection, but also against the unrelated pathogenSclerotinia sclerotiorum. In contrast to dichloroisonicotinic acid, an artificial inducer of systemic acquired resistance, which was increasingly effective with doses ranging from 0.25 to 5mole per plant, the basic elicitin cryptogein exhibited a threshold effect, inducing near total resistance and extensive leaf necrosis above 0.1 nmole per plant. Between 1 and 5 nmole, acidic elicitins (capsicein and parasiticein) protected tobacco plants with hardly any necrotic symptom. Elicitins exhibited similar effects in various tobacco cultivars andNicotiana species, although with quantitative differences, but induced neither necrosis nor protection in other SolanaceÆ (tomato, petunia and pepper). Among 24 additional species tested belonging to 18 botanical families, only some BrassicaceÆ, noticeably rape, exhibited symptoms in response to elicitins, in a cultivar-specific manner. Elicitins appear to be natural specific triggers for systemic acquired resistance and provide a tool for unraveling the mechanisms leading to its establishment.Abbreviations AR acquired resistance - HR hypersensitive response - INA 2,6-dichloroisonicotinic acid - Ppn Phytophthora parasitica var.nicotianae - SAR systemic acquired resistance     

Sternal recumbency or suspension by the hind legs immediately after delivery improves respiratory and metabolic adaptation to extra uterine life in newborn calves delivered by caesarean section

The aim of this study was to evaluate the effect of body positioning immediately after delivery on respiratory and metabolic adaptation to extra-uterine life in newborn calves. One hundred and one Belgian White and Blue calves were delivered at term by an elective caesarean section and were assigned into three categories according to the body position imposed immediately after umbilical cord rupture: 71 calves were placed in lateral recumbency; 16 calves were placed in sternal recumbency and 14 calves were suspended by the hind legs for less than 90 seconds (75 +/- 5 s). Following this initial body position, the calves were allowed to move without restraint. They were examined at birth, 5, 15, 30, 45 and 60 minutes, and 2, 3, 6, 12 and 24 hours after birth by the following measurements: physical examination, heart rate, arterial blood gas analysis, pulmonary function tests using the esophageal balloon catheter technique, arterial and venous blood acid-base balance analysis, rectal temperature, jugular venous blood sampling for the determination of blood glucose, plasma lactate and serum cortisol concentrations, haematologic variables and passive immune transfer variables. Body positioning immediately after delivery clearly influenced respiratory and metabolic adaptation to extra-uterine life in term calves delivered by an elective caesarean section. Systematic sternal recumbency and suspension by the hind legs for less than 90 seconds immediately after umbilical cord rupture had a positive functional impact on postnatal pulmonary mechanics and gas exchange and on postnatal correction of mixed acidosis present at birth, contributing in turn to an enhanced passive immune transfer. These two body positions should be encouraged to improve adaptation at birth in healthy term calves delivered by an elective caesarean section. Evaluation of possible side-effects is required before application in severely asphyxiated calves.     

A high virulence and pathotype diversity of Puccinia striiformis f.sp. tritici at its centre of diversity,the Himalayan region of Pakistan

Information on the pathogen virulence profile and diversity across locations is crucial for host germplasm improvement and deployment. The rapid acquisition of virulence to host resistance by the wheat yellow/stripe rust pathogen (Puccinia striiformis f.sp. tritici: PST), makes it crucial to know about its virulence and pathotype diversity. Recent studies have shown the plausible centre of origin of the pathogen in the Himalayan region, with Pakistan being the most ancestral to all other worldwide populations. To assess the status of virulence and pathotype diversity in the Himalayan region of Pakistan, a set of 127 PST infected wheat samples from eight locations were collected, multiplied and pathotyped using a set of 36 differential lines from the world set, European and Chinese sets, and 9 Avocet Yr isolines. Virulence (Vr) was recorded to 18 out of 24 tested yellow rust resistance (Yr) genes, while a total of 53 pathotypes were detected out of 127 isolates tested. Virulence was found to the resistance genes rarely deployed in Pakistan (Vr8) or even worldwide level (Vr5), while virulence to Vilmorin 23 (Yr3+) was absent in Pakistan, which is common in Europe. None of the pathotypes was dominant across all locations, however, no clear spatial structuring was observed for the studied locations. Our results suggested a high virulence and pathotype diversity in line with the previously proposed potential role of sexual recombination in the temporal maintenance of PST in the Himalayan region of Pakistan. This information should be useful in host resistance gene improvement and deployment.     

Differential susceptibility to tetracycline,oxytetracycline and doxycycline of the calf pathogens Mannheimia haemolytica and Pasteurella multocida in three growth media

For clinical isolates of bovine Mannheimia haemolytica and Pasteurella multocida, this study reports minimum inhibitory concentration (MIC) differences for tetracycline, oxytetracycline and doxycycline between cation‐adjusted Mueller‐Hinton broth (CAMHB), foetal bovine serum (FBS) and Roswell Park Memorial Institute (RPMI) medium. MICs were determined according to CLSI standards and additionally using five overlapping sets of twofold dilutions. Matrix effect: (a) free drug MICs and minimum bactericidal concentrations (MBC) for all drugs were significantly higher in FBS than in CAMHB for both pathogens (p < 0.001); (b) MICs and MBCs were higher for CAMHB and FBS compared to RPMI for P. multocida only. Net growth rate for P. multocida in CAMHB was significantly slower than in FBS and higher than in RPMI, correlating to MIC and MBC ranking. Drug effect: doxycycline MICs and MBCs were significantly lower (p < 0.001) in both CAMHB and FBS than tetracycline and oxytetracycline for both pathogens. Only for M. haemolytica were oxytetracycline MIC and MBC significantly lower than tetracycline, precluding the use of tetracycline to predict oxytetracycline susceptibility in this species. Determining potencies of tetracyclines in a physiological medium, such as FBS, is proposed, when the objective is correlation with pharmacokinetic data for dosage determination.     

In vitro micrografting and its applications to fruit science

Improvements have been brought to in vitro micrografting. The breaking of dormancy by dipping the seeds of the rootstock in concentrated solutions of benzylaminopurine avoids having recourse to long stratification in the cold (60–120 days according to species). The initial pre-treatment of apices with cytokinin allows their development and facilitates later grafting. Moreover, adding DIECA to the cut sections avoids oxidation and, together with the insertion of a piece of agar between apex and rootstock, increases the success of micrografting. Finally, a special technique of in vivo micrografting of pretreated apices on young plants has been developed.Micrografting is commonly used to obtain peach trees free of Sharka and NRS viruses, and to study incompatibility mechanisms in heterografts, leading to an early diagnosis of incompatibilities.     

The behaviour of residues of benzoylprop-ethyl and its breakdown products in wheat

Samples of wheat grain and straw have been analysed from trials with the wild oat herbicide benzoylprop-ethyl ( I ) in several countries. Following recommended commercial treatments (application of 1.0–1.6 kg ha^?1 at Feekes growth stage G-J), total residues of I and its hydrolysis product N-benzoyl-N-(3,4-dichlorophenyl)-DL - alanine (free and conjugated) were low and in the majority of instances they were < 0.01 mg kg^?1 in samples of grain from the UK, although rather higher residues were detected in some grain samples from other countries. Residues in straw were higher, but normally did not exceed 2 mg kg^?1, and were rather variable, possibly as a result of differences in agricultural practice.     

Analysis of growth curve parameters of Gobra zebu females in Senegal

Summary Analysis of growth curve parameters was performed using body weight data collected from 1968 through 1980 at Dahra Research Station, Senegal. Month of birth had little or no effect on mature size and maturing rate. Females born from mid-wet through mid-dry seasons were likely to reach lighter mature weights than those born from mid-dry through mid-wet seasons. Year of birth affected both mature weight and maturing rate (P<0.01 and P<0.001 respectively). Sire had effects (P<0.05) on maturing rate and no effect on mature size. Genetic correlations between maturing rate and body weights at birth, weaning, 12 and 18 months were 0.45±0.51, –0.21±0.52, –0.61±0.57 and –0.76±0.51 respectively. Selection for maturing rate in Gobra females would be expected to decrease weaning and post-weaning weights. The least squares means of mature size and maturing rate were 398.83±45.81 kg and 0.187% per day respectively. Gobra zebu females were about 50 and 99% mature at about 12 and 87.6 months respectively.

---

Analysis De Los Prametros De Las Curvas De Crecimiento De Hembras Cebu Gobra

Resumen Se llevó a cabo un análisis de los parámetros de las curvas de crecimiento de hembras Cebú Gobra, utilizando los datos de peso colectados desde 1968 hasta 1980 en la Estación de Investigación de Dahra, Senegal. El mes de nacimiento tuvo poco o ningun efecto, en el tamaño adulto y tasa de maduración. Las hembras nacidas entre la mitad de la estación lluviosa y la mitad de la estación seca, alcanzaron pesos maduros menores que aquellas nacidas entre la mitad de la estación seca y la mitad de la estación lluviosa. El año de nacimiento afectó tanto al peso en edad madura, como a la tasa de maduración (P<0·01 y P<0·001 respectivamente). El reproductor utilizado tuvo efecto (P<0·05) sobre la tasa de maduración y ninguno sobre el tamaño en la edad adulta. Las correlaciones genéticas entre la tasa de maduración y peso corporal al nacer, al destete, 12 y 18 meses, fueron 0·45±0·51, –0·21±0·52, –0·61±0·57 y –0·76±0·51 respectivamente. Se esperaria, que la selección para tasa de maduración en hembras Gobra, disminuiría los pesos al destete y post-destete. Les medias de mínimos cuadrados de tamaño a edad madura y tasa de maduración, fueron 398·83±45·81 kg y 0·187% por día respectivamente. Las hembras Gobra Cebú, fueron cerca del 50 y 99% maduras cerca de los 12 y 87·6 meses respectivamente.

---

Analyse Des Parametres Des Courbes De Croissance Des Vaches Zebu Gobra

Résumé On a entrepris une analyse des paramètres des courbes de croissance en utilisant les données pondéralés enregistrées de 1968 à 1980 à la station de recherches de Dahra, au Sénégal. Le mois de naissance n'a que peu ou pas d'effet sur la taille à l'état adulte et le taux de croissance. Les vaches nées du milieu de la saison des pluies au milieu de la saison sèche ont plus de chance d'avoir des poids adultes moins élevés que celles nées du milieu de la saison sèche au milieu de la saison des pluies. L'année de naissance affecte à la fois le poids adulte et le taux de croissance. Le mâle a un effet sur le taux de croissance et aucun sur la taille adulte. Les corrélations génétiques entre le taux de croissance et les poids à la naissance, au sevrage, à 12 et 18 mois sont respectivement de 0.45±0.51, –0.21±0.52, –0.61±0.57 et –0.76±0.51. On doit s'attendre à ce que la sélection effectuée sur le taux de croissance des femelles Gobra diminue les poids au sevrage et après sevrage. Les moyennes des moindres carrés des poids adultes et des taux de croissance sont respectivement de 398.83±45.81 kg et de 0.187 p. 100 par jour. Les vaches zébu Gobra sont adultes à 50 p. 100 et 99 p. 100 respectivement à environ 12 et 87.6 mois.