Histopathological and parasitological study of the gastrointestinal tract of dogs naturally infected with Leishmania infantum     

Aldair JW Pinto  Maria M Figueiredo  Fabiana L Silva  Trycia Martins  Marilene SM Michalick  Washington L Tafuri  Wagner L Tafuri 《Acta veterinaria Scandinavica》2011,53(1):67

Background

The aim of this study was to provide a systematic pathological and parasitological overview of the gastrointestinal tract (GIT), including the stomach, duodenum, jejunum, ileum, caecum and colon, of dogs naturally infected with Leishmania.

Methods

Twenty mongrel dogs naturally infected with Leishmania (Leishmania) infantum and obtained from the Control Zoonosis Center of the Municipality of Ribeirão das Neves, Belo Horizonte Metropolitan area, Minas Gerais (MG) state, Brazil, were analyzed. The dogs were divided into two groups: Group 1 comprised nine clinically normal dogs and group 2 comprised 11 clinically affected dogs. After necropsy, one sample was collected from each GIT segment, namely the stomach, duodenum, jejunum, ileum, caecum and colon. Furthermore, paraffin-embedded samples were used for histological and parasitological (immunohistochemistry) evaluation and a morphometrical study were carried out to determine the parasite load (immunolabeled amastigote forms of Leishmania). The Friedman and the Mann Whitney tests were used for statistical analysis. The Friedman test was used to analyze each segment of the GIT within each group of dogs and the Mann Whitney test was used to compare the GIT segments between clinically unaffected and affected dogs.

Results

The infected dogs had an increased number of macrophages, plasma cells and lymphocytes, but lesions were generally mild. Parasite distribution in the GIT was evident in all intestinal segments and layers of the intestinal wall (mucosal, muscular and submucosal) irrespective of the clinical status of the dogs. However, the parasite load was statistically higher in the caecum and colon than in other segments of the GIT.

Conclusion

The high parasite burden evident throughout the GIT mucosa with only mild pathological alterations led us to consider whether Leishmania gains an advantage from the intestinal immunoregulatory response (immunological tolerance).  相似文献   

Long-term productivity growth and sustainability of Greek irrigated agriculture     

SM Fakhrul Islam  Mohd. Kamruzzaman 《Archives of Agronomy and Soil Science》2013,59(3):311-324

The present study examines the long-term productivity growth and sustainability of Greek irrigated agriculture. A log linear trend model was used to measure long-term productivity growth, and the total factor productivity (TFP) approach measures the sustainability of the irrigated production system. A time series database of inputs and outputs data were used for the production period of 1961?–?2001 (41 years) which revealed that there is an increasing trend in the irrigated area of the country. The annual growth rate of the irrigated area is 2.6% during this time period. The long-term trends in yields of crops grown in irrigated agriculture are positive. Fertilizer use rate per ha sharply increases during this period. The productivity of irrigated Greek agriculture also increases over the time period as a result of the introduction of High Yielding Variety (HYV), seed, fertilizer and water technology. The measurement of TFP indices indicates that the long-term trend in productivity growth of irrigated Greek agricultural system is positive. The result implies that the irrigated Greek agricultural production system has long-term sustainability. The result also indicates that fertilizer, fixed capital, rainfall and temperature are positively contributing to the mean production of Greek irrigated agriculture. On the other hand, pesticide, labour and fixed capital reduces variability of irrigated agriculture. To this end, long-term agricultural sustainability depends on patterns of input use.  相似文献   

Influence of cultivar resistance toVerticillium SPP. On potato early dying     

T. A. Wheeler  R. C. Rowe  R. M. Riedel  L. V. Madden 《American Journal of Potato Research》1994,71(1):39-57

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Seasonal variation and effects of wheat rotation on populations ofVerticillium dahliae Kleb. in Ohio potato field soils     

T. R. Joaquim  V. L. Smith  R. C. Rowe 《American Journal of Potato Research》1988,65(8):439-447

Soil population levels ofVerticillium dahliae in Ohio were monitored from May–October, 1982–1985, in 15 fields in potato-wheat rotation and two fields in potato monoculture. Population levels in fields in rotation ranged from 0 to 86 microsclerotia/10 g of air-dried soil with average values during each 6-month sampling period of 9.7, 12.9, 9.6 and 19.6 microsclerotia/10 g of soil for 1982, 1983, 1984 and 1985, respectively. In at least 2/3 of the fields sampled each year, soil populations ofV. dahliae peaked in either July or August, regardless of whether fields were under wheat rotation or potato monoculture. Of the 15 fields under potato-wheat rotation, 13 showed a general pattern of increased populations ofV. dahliae in one or both years following cropping to potato. Among those 13, significantly higher populations (P < 0.05) were observed in one wheat field in 1983 and in eight fields in 1985. In the two fields in potato monoculture, one consistently had population levels ofV. dahliae 3–4 times higher than any other field sampled in this study. Factors that may contribute to periodic changes inV. dahliae populations, implications of these changes in interpreting soil population data, and usefulness of a potato-wheat rotation in managingV. dahliae populations in Ohio are discussed.  相似文献   

Selection and utilization of solanum phureja clones with high resistance to different strains of pseudomonas solanacearum     

Luis Sequeira  P. R. Rowe 《American Journal of Potato Research》1969,46(12):451-462

Over 250 accessions ofSolanum phureja from Colombia and 300S. phureja—S. tuberosum hybrids were screened in the greenhouse for resistance toPseudomonas solanacearum (isolate K-60). Each plant was inoculated by stem puncture at the pre-bud stage and then held at a constant 28 C for 15 days. Seventeen clones with different levels of resistance to K-60 were inoculated with nine additional isolates representing all three races of the bacterium. The reactions of individual clones varied from resistance to almost all isolates, resistance to only one isolate, or complete susceptibility. Crosses amongS. phureja clones and betweenS. phureja and 24-chromosomeS. tuberosum stocks gave progeny with various percentages of resistant plants. Clones with resistance equal to that inS. phureja were found in theS. phureja × S. tuberosum crosses. Tests conducted in growth chambers showed that resistance was expressed more frequently at high light intensity (2000 ft-c) than at low intensities (1300 ft-c) at 24 C and 28 C. Resistance appears to be relatively simply inherited and the prospects for transferring a high level of resistance into cultivated forms are promising.  相似文献   

Performance of diploid and vegetatively doubled clones of Phureja-haploid tuberosum hybrids     

P. R. Rowe 《American Journal of Potato Research》1967,44(6):195-203

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Chromatographic studies on the origin of the cultivated diploid potatosolanum × ajanhuiri juz. et buk     

Z. Huamán  J. G. Hawkes  P. R. Rowe 《American Journal of Potato Research》1983,60(5):361-367

The leaf phenolics of the potato speciesS. × ajanhuiri, S. stenotomum, S. megistacrolobum and the artificial F₁ S. stenotomum × S. megistacrolobum hybrids have been compared using thin layer chromatography The wild potatoS. megistacrolobum produced unidentified phenolic compounds which were present in the artificialS. stenotomum × S. megistacrolobum hybrids and the YARI group ofS. × ajanhuiri, but which were absent inS. stenotomum. This further supports the hypothesis thatS. X ajanhuiri is of hybridogenic origin and was derived from natural crosses between the cultivatedS. stenotomum and the wildS. megistacrolobum.  相似文献   

Abstracts 59th annual meeting Potato Association of America     

D. E. Hudson  M. D. Volz  B. B. DePhillips  Gene A. Mathia  Frank Haynes  N. A. Wynn  Allen E. Abrahams  Lewis A. Schaper  Paul H. Orr  Earl C. Yaeger  Combs Joseph  Robert L. Mercer  T. O. Diener  W. B. Raymer  R. P. Singh  T. J. Morris  F. E. Manzer  J. A. Frank  Otto E. Schultz  J. E. Huguelet  D. Corsini  G. F. Stallknecht  J. J. Pavek  P. Jatala  P. R. Rowe  S. J. Turner  S. S. Leach  Raymon E. Webb  D. R. Douglas 《American Journal of Potato Research》1975,52(8):239-248

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Inbreeding in cultivated diploid potatoes     

H. De Jong  P. R. Rowe 《Potato Research》1971,14(2):74-83

Summary The effects of inbreeding in cultivated diploid potatoes were studied by using self-fertile hybrids from crosses between Group Phureja and Group Stenotomum and haploids of Group Tuberosum. S₁, S₂ and S₃ progenies usually exhibited decreased performance and vigour with increased inbreeding. In most families the inbreeding depression seemed to coincide with a curve claculated on the basis of the expected loss of heterozygosity in a diploid organism. The performance of some progenies deviated markedly from expectations apparently because a non-random sample of parents contributed to later generations. Many inbred genotypes were lost owing to poor seedling vigour or tuberization. This indicated the presence of many harmful recessive genes. The rapid increase in homozygosity following selfing at the diploid level provides a means for developing homozygous clones with a potential for use in future genetic investigations.

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Zusammenfassung Inzucht bei kultivierten diploiden Kartoffeln wurde m?glich, nachdem man herausgefunden hatte, dass Kreuzungen zwischen kultivierten diploiden Arten und gewissen Haploiden vonSolanum tuberosum in hohem Masse selbstfertil sind. Die ursprüngliche genetische Basis dieses Versuches bestand aus 4 Familien, die durch Kreuzungen zwischen der Gruppe Phureja und der Gruppe Stenotomum mit der Gruppe Tuberosum haploidUS-W 4 erzielt wurden. Bei einer Anzahl der untersuchten Eigneschaften stimmte die durchschnittliche Inzuchtdepression der 4 Familien mit einer Kurve überein, die auf der Basis der Heterozygotie in einem diploiden Organismus (Tabellen 1, 2 und Abb. 1) berechnet wurde. Die vier Familien reagierten unterschiedlich auf die Einkreuzung (Tabelle 1). Dies kann teilweise auf genetische Unterschiede zwischen den ursprünglichen Elternpopulationen (S₀) und auf eine Auslese auf Frohwüchsigkeit sowohl im geschlechtlichen als auch im ungeschlechtlichen Vermehrungszyklus zurückgeführt werden. Nur die kr?ftigeren Pflanzen blühten, und nur ein kleiner Teil davon war in den fortgeschrittenen Inzuchtgenerationen selbstfertil (Tabelle 4). Dies zeigt, dass Allele für Selbstunvertr?glichkeit in den Populationen noch vorhanden sind. Der niedrigere Grad der Selbstfertilit?t, ausgedrückt in Samen pro Frucht, weist beim Vergleich mit der Pollen- und der Eizellenfertilit?t darauf hin, dass rezessive lethale Gene vorhanden sind. Fortgeschrittene Inzuchtgenerationen wiesen eine abnehmende Knollenbildung auf (Tabelle 3). Beim Vergleich der Leistung der ersten Klongenerationen mit jener der ungeschlechtlichen Nachkommenschaften war die Depression in bezug auf die entsprechenden S₀'s bei den meisten Nachkommenschaften kleiner als bei ihren entsprechenden ungeschlechtlichen Elternpopulationen (Tabellen 1 und 2). Es wurden einige kr?ftige S₅-Linien erzielt, manche von ihnen besitzen einen hohen Grad von Einheitlichkeit. Die rasche Abnahme der Frohwüchsigkeit nach der Einkreuzung deutet darauf hin, dass ein Heterosiseffekt bei Kreuzung fortgeschrittener Inzuchtklone erreicht werden k?nnte. Da Inzucht durch Selbstung eine Auslese auf Selbstfertilit?t erfordert, k?nnte dieses Vorgehen einige homozygote, selbstfertile Linien hervorbringen, was für eine Untersuchung der Genetik der Selbstfertilit?t sehr nützlich w?re.

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Résumé L'autofécondation chez les pommes de terre cultivées diplo?des devint possible quand on découvrit que des croisements entre espèces cultivées diplo?des et certains haplo?des deSolanum tuberosum étaient hautement auto-fertiles. La base génétique initiale de la présente étude comprend 4 familles issues de croisements entre groupe Phureja et groupe Stenotomum avec le haplo?deUS-W4 du groupe Tuberosum. Pour un certain nombre de caractères, la dépression moyenne de consanguinité des 4 familles co?ncide avec une courbe calculée sur la base de l'hétérozygotie dans un organisme diplo?de (Tableaux 1, 2 et Fig. 1). Les 4 familles réagissaient différemment à l'autofécondation (Tableau 1). Ceci peut partiellement être attribué à des différences génétiques entre les populations parentales orignales (S₀) et à une sélection pour la vigueur dans les cycles de reproduction à la fois sexuelle et asexuelle. Seules les plantes les plus vigoureuses fleurissaient, et seule une petite partie de celles-ci étaient autofertiles dans les générations successives autofécondées (Tableau 4). Ceci indique que les allèles d'autoincompatibilité sont toujours présents dans les populations. Le niveau plus faible d'autofertilité exprimée par le nombre de graines par fruit, quand on la compare à la fertilité du pollen et de l'ovule fait supposer que des gènes létaux récessifs sont présents. Les générations autofécondées successives montrent une tubérisation décroissante (Tableau 3). Quand on compare les performances des premières générations clonales avec les descendances assexuées, la dépression, comparée aux S₀ respectifs, est plus faible chez la plupart des descendances que chez les populations parentales assexuées respectives (Tableaux 1 et 2). Plusieurs lignées S₅ bien vigoureuses ont été obtenues, plusieurs de celles-ci montrant un haut degré d'uniformité. Le déclin rapide dans la vigueur après autofécondation suggère qu'on peut obtenir des hybrides vigoureux de croisements entre clones précédemment autofécondés. Puisque la consanguinité par autofécondation impose une sélection pour l'autofertilité, on peut de la sorte produire quelques lignées homozygotes auto-fertiles qui pourraient être utiles pour une recherche sur la génétique de l'autofertilité.

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Cooperative investigations of the Crops Research Division, Agricultural Research Service, U.S. Department of Agriculture, and the Wisconsin Agricultural Experiment Station.  相似文献   

Future challenges in managing potato health     

Randall C. Rowe 《American Journal of Potato Research》1992,69(11):769-775

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