Fungicide sensitivity and monocyclic parameters related to the Phakopsora pachyrhizi–soybean pathosystem from organic and conventional soybean production systems

The failure of chemical control of soybean rust has been related to the selection of less sensitive isolates, and the infection capacity of such isolates could have implications for the management of the disease. The aims of the present study were to compare the sensitivity to tebuconazole and azoxystrobin and the monocycle of soybean rust using isolates of Phakopsora pachyrhizi from two soybean fields with different production systems (organic and conventional) in 2012/13 and 2013/14 seasons, and to monitor mutations in the CYP51 gene. To assess the sensitivity to tebuconazole and azoxystrobin, detached leaf tests and in vitro germination, respectively, were used. To evaluate the monocycle, detached leaves were inoculated with a urediniospore suspension and evaluated daily by counting the number of uredia. The occurrence of the mutations in CYP51 was investigated by a pyrosequencing assay. In both 2012/13 and 2013/14 seasons, the EC₅₀ to tebuconazole was lower for the population from the organic system (0.41 and 0.10 μg mL^?1, respectively) compared to the conventional system (1.60 and 4.44 μg mL^?1, respectively), while the EC₅₀ to azoxystrobin was similar for both populations. The lower sensitivity to tebuconazole and azoxystrobin was associated with F120L + Y131H mutations in CYP51, and the F129L mutation in CYTB, respectively. The monomolecular model fitted to monocycle data and parameters related to the maximum asymptote and the AUDPC were superior for organic than the conventional system.     

Characterization and quantitation of polyphenolic compounds in bark, kernel, leaves, and peel of mango (Mangifera indica L.)

The contents of secondary plant substances in solvent extracts of various byproducts (barks, kernels, peels, and old and young leaves) in a range of Brazilian mango cultivars were identified and quantitated. The results show that the profiles of secondary plant substances such as xanthone C-glycosides, gallotannins, and benzophenones in different byproducts vary greatly but are fairly consistent across cultivars. The free radical scavenging activity of the solvent extracts was evaluated using a high-performance liquid chromatography-based hypoxanthine/xanthine oxidase assay and revealed dose-dependent antioxidant capacity in all extracts. Four (mangiferin, penta- O-galloyl-glucoside gallic acid, and methyl gallate) of the major phenolic compounds detected were also evaluated in additional in vitro bioassay systems such as oxygen radical absorbance capacity, 2,2-diphenyl-1-picrylhydrazyl, and ferric reducing ability of plasma. Mangiferin in particular, detected at high concentrations in young leaves (Coite = 172 g/kg), in bark (Momika = 107 g/kg), and in old leaves (Itamaraka = 94 g/kg), shows an exceptionally strong antioxidant capacity.     

Soil‐carbon preservation through habitat constraints and biological limitations on decomposer activity

We review recent experimental results on the role of soil biota in stabilizing or destabilizing soil organic matter (SOM). Specifically, we analyze how the differential substrate utilization of the various decomposer organisms contributes to a decorrelation of chemical stability, residence time, and carbon (C) age of organic substrates. Along soil depth profiles, a mismatch of C allocation and abundance of decomposer organisms is consistently observed, revealing that a relevant proportion of soil C is not subjected to efficient decomposition. Results from recent field and laboratory experiments suggest that (1) bacterial utilization of labile carbon compounds is limited by short‐distance transport processes and, therefore, can take place deep in the soil under conditions of effective local diffusion or convection. In contrast, (2) fungal utilization of phenolic substrates, including lignin, appears to be restricted to the upper soil layer due to the requirement for oxygen of the enzymatic reaction involved. (3) Carbon of any age is utilized by soil microorganisms, and microbial C is recycled in the microbial food web. Due to stoichiometric requirements of their metabolism, (4) soil animals tend to reduce the C concentration of SOM disproportionally, until it reaches a threshold level. The reviewed investigations provide new and quantitative evidence that different soil C pools underlie divergent biological constraints of decomposition. The specialization of decomposers towards different substrates and microhabitats leads to a relatively longer persistence of virtually all kinds of organic substrates in the nonpreferred soil spaces. We therefore propose to direct future research explicitly towards such biologically nonpreferred areas where decomposition rates are slow, or where decomposition is frequently interrupted, in order to assess the potential for long‐term preservation of C in the soil.     

Insect peptide hormones: a selective review of their physiology and potential application for pest control

Our knowledge on primary structure, synthesis, release, receptor binding, structure-activity relationships, mode of action and degradation of, mainly, neuropeptides from insects has increased dramatically during the last 10 years or so. Here, five case studies are presented, which deal selectively with effects on: reproduction (trypsin modulating oostatic factor in mosquito); energy metabolism, locomotion and the immune system (adipokinetic hormones); water and ion balance, and feeding behaviour (diuretic hormones, kinins, sulfakinins); sex attraction (pheromone biosynthesis activating neuropeptide); and growth and development, and muscle activity (allatostatins). The literature is reviewed in the context of how the knowledge on neuropeptides has been and can be used for the design of novel, safe and selective compounds to control pest insects in the foreseeable future.     

Field efficacy of pyraclostrobin against populations of Pyrenophora teres containing the F129L mutation in the cytochrome b gene

Journal of Plant Diseases and Protection - Resistance of plant pathogenic fungi towards QoI fungicides is mainly caused by two mutations in the cytochrome b gene, the F129L and G143A. In...     

Über die Wollverdauung der Raupen vonHofmannophila pseudospretella (Lepidopt. Oecophoridae)

Zusammenfassung Die Versuche zur Klärung der Wollverdauung bei Raupen vonHofmannophila pseudospretella führten zu folgenden Ergebnissen:1. Die Fähigkeit, Wolle zu verdauen, ist bei allen Raupenstadien vorhanden.2. Bei älteren Raupen ist die Verdauung stärker als bei jüngeren.3. Werden neben Wolle auch andere organische Materialien aufgenommen, so wird die Wolle intensiver als Nahrung ausgewertet.4. Die Feuchtigkeit des Milieus hat keinen Einfluß auf die Fähigkeit, Wolle zu verdauen.5. Vor der Häutung unterbrechen die Raupen die Aufnahme von Wolle und erneuern während der Häutung das Epithel des Mitteldarmes stoßweise.6. Biologisch istHofmannophila pseudospretella zu den Vorratsschädlingen und nicht zu den obligatorischen Wollschädlingen zu rechnen.

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Summary The experiments for the digestibility of wool of the larvas ofHofmannophila pseudospretella had following results:1. In every stage of development the larvas can digest wool.2. The elder larvas digest the wool in a stronger way.3. In case that the larvas eat other organic substance with the wool, wool is still more utilized as food.4. The humidity of the surroundings is of no influence for the ability to digest wool.5. Before casting the skin the larvas interrupt eating wool and while casting the skin, they renovate the epithelium of the middle intestine.6. Concerning biologieHofmannophila pseudospretella must be looked at principally as a vermin of provisions and not as belonging to the obligatory vermins of wool.

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Résumé Les expériments concernant la digestibilité de laine des chenilles deHofmannophila pseudospretella donnaient les résultats suivants:1. La capacité pour digérer laine se trouve en toute phase du développement.2. Les chenilles plus âgées digèrent plus vivement.3. En cas de mangeaille d'autres substances organiques avec, la laine est utilisée comme nourriture encore plus intensivement.4. L'humidité du lieu n'est d'aucune influence sur la digestibilité.5. Avant de se dépouiller les chenilles interrompent la susception de laine, et, pendant l'enlèvement de la peau, elles renouvellent l'épithélium de l'intestin moyen d'un seul coup.6. Quant à la biologie il faut considérerHofmannophila pseudospretella comme insecte nuisible aux provisions et non comme insecte nuisible obligatoire à la laine.

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Herrn Dr. Adolf Herfs zum 70. Geburtstag gewidmet.     

COMBINATION OF COMPUTED TOMOGRAPHIC IMAGING CHARACTERISTICS OF MEDIAL RETROPHARYNGEAL LYMPH NODES AND NASAL PASSAGES AIDS DISCRIMINATION BETWEEN RHINITIS AND NEOPLASIA IN CATS

Feline nasal diseases are a diagnostic challenge. The objective of this retrospective, cross‐sectional study was to determine whether computed tomography (CT) imaging characteristics of the medial retropharyngeal lymph nodes (MRPLN), alone or in combination with CT imaging characteristics of the nasal passages, could aid in differentiation between rhinitis and nasal neoplasia. Cats were recruited from record archives at two veterinary facilities during the period of 2008–2012. Selection criteria were presentation for chronic nasal discharge, contrast‐enhanced CT of the head that included the MRPLN, and rhinoscopic nasal biopsy resulting in diagnosis of rhinitis or neoplasia. For each CT scan, two board‐certified veterinary radiologists recorded MRPLN size, attenuation, heterogeneity, contrast‐medium enhancement, margination, shape, presence of a lymph node hilus, perinodal fat, turbinate lysis, paranasal bone lysis, and nasal mass. Both readers were unaware of patient information at the time of CT interpretation. Thirty‐four cats with rhinitis and 22 cats with neoplasia were included. Computed tomographic characteristics significantly associated with neoplasia included abnormal MRPLN hilus (OR 5.1), paranasal bone lysis (OR 5.6), turbinate lysis (5.6), mass (OR 26.1), MRPLN height asymmetry (OR 4.5), and decreased MRPLN precontrast heterogeneity (OR 7.0). The combined features predictive of neoplasia were a nasal mass with abnormal hilus (OR 47.7); lysis of turbinates/paranasal bones with abnormal MRPLN hilus (OR 16.2). Findings supported the hypothesis that combining CT features of the nasal passages and MRPLN aided in differentiating rhinitis from neoplasia in cats.     

Flow cytometric analysis on cross-reactivity of human-specific CD monoclonal antibodies with splenocytes of Aotus nancymaae, a non-human primate model for biomedical research

The reactivity of 204 monoclonal antibodies (mAb) out of 377 commercially available antibodies collected by the animal homologue group of the HLAD8 was analyzed by single colour flow cytometry. Most of these mAb were originally developed against human cell surface molecules. Fifty-eight mAb (28%) showed reactivity with spleen cells of Aotus nancymaae, a non-human primate animal model in biomedical research. Out of these 58 mAb, 22 also showed reactivity with mononuclear cells derived from rhesus macaques and cynomolgus monkeys indicating that the epitopes recognized are evolutionary conserved between human, Old and New World monkeys. This novel panel of A. nancymaae reactive mAb will increase the potential to explore complex host-pathogen interactions in non-human primate animal models, particularly in malaria vaccine research.