Detection of DNA of the finch polyomavirus in diseases of various types of birds in the order Passeriformes

Between 2000 and 2004 a disease occurred in an aviary in Germany affecting various bird species belonging to the order Passeriformes including Collared Grosbeaks (Mycerobas affinis), Eurasian Bullfinches (Pyrrhula pyrrhula griseiventris), Brown Bullfinches (Pyrrhula nipalensis), Grey-headed bullfinches (Pyrrhula erythaca) and Yellow-bellied Tits (Periparus venustulus).The major clinical signs included increased mortality of fledglings and young birds, as well as feather disorders and feather loss in adult birds. In addition, adult Eurasian Bullfinches showed in one year a disease course, in which the major symptom was inflammation of the skin beginning on the basis of the beak and spreading over the head occurring a few days before death. Bacteriological and parasitological investigations did not reveal any consistent findings. Using a newly developed polymerase chain reaction protocol, DNA of the recently discovered finch polyomavirus (FPyV) was demonstrated in several affected birds. Because of the consistent detection of FPyV-DNA and the similarity of the symptoms with those observed during infection with the closely related avian polyomavirus in other bird species, an etiological role of FPyV in the observed disease is assumed.     

The Effect of Inoculation Treatment and Long-term Application of Moisture on Fusarium Head Blight Symptoms and Deoxynivalenol Contamination in Wheat Grains

Fusarium head blight (FHB) is an important disease of wheat, which can result in the contamination of grains with mycotoxins such as deoxynivalenol (DON). Artificial inoculation of flowering ears with conidial suspensions is widely used to study FHB diseases. Our goal was to compare four inoculation treatments in which a conidial suspension was sprayed on flowering ears and to study the effect of the application of moisture during kernel setting and filling with a mist-irrigation system. Ten wheat genotypes were inoculated with a DON-producing Fusarium culmorum strain. Inoculation treatments varied in time of application of the inoculum (morning or evening) and in the method of controlling humidity during inoculation (bagging or mist irrigation). A wet season was simulated with a mist-irrigation system, keeping the crop canopy wet for at least 26 days after flowering. The severity of FHB symptoms (area under disease progress curve (AUDPC)), yield loss and DON contamination in the grains were determined. AUDPC data obtained with the different inoculation treatments were highly correlated (r=0.85–0.95). Mist irrigation after inoculation resulted in a higher mean disease severity, but in a overall lower toxin contamination as compared to the non-irrigated treatments. Genotypic differences in DON accumulation were present: for one wheat line toxin contamination significantly increased when irrigated, while two genotypes accumulated significantly less toxin. The closest relationships (r=0.73–0.89) between the visual symptoms and the DON content were obtained under moderate mean infection pressure. This relation between visual symptoms and the DON content deteriorated at higher infection levels.     

Fusarium oxysporum f. sp. radicis‐vanillae is the causal agent of root and stem rot of vanilla

Root and stem rot (RSR) is a very detrimental disease of vanilla worldwide. Fusarium oxysporum is frequently associated with the disease but other Fusarium species are also reported. In this international study, 52 vanilla plots were surveyed in three of the most important vanilla producing countries (Madagascar, Reunion Island and French Polynesia) in order to determine the aetiology of RSR disease. Subsets from the 377 single‐spored Fusarium isolates recovered from rotten roots and stems in the surveys were characterized by molecular genotyping (EF1α and IGS gene sequences) and pathogenicity assays on Vanilla planifolia and V. ×tahitensis, the two commercially grown vanilla species. Fusarium oxysporum was shown to be the principal species responsible for the disease, representing 79% of the isolates recovered from the RSR tissues, 40% of which induced severe symptoms on inoculated plantlets. Fusarium oxysporum isolates were highly polyphyletic regardless of geographic origin or pathogenicity. Fusarium solani, found in 15% of the samples and inducing only mild symptoms on plantlets, was considered a secondary pathogen of vanilla. Three additional Fusarium species were occasionally isolated in the study (F. proliferatum, F. concentricum and F. mangiferae) but were nonpathogenic. Histopathological preparations observed in wide field and multiphoton microscopy showed that F. oxysporum penetrated the root hair region of roots, then invaded the cortical cells where it induced necrosis in both V. planifolia and V. ×tahitensis. The hyphae never invaded the root vascular system up to 9 days post‐inoculation. As a whole, the data demonstrated that RSR of vanilla is present worldwide and that its causal agent should be named F. oxysporum f. sp. radicis‐vanillae.     

Aktuelle Fragen der Schädlingsbekämpfung in Lebensmittelbetrieben unter besonderer Berücksichtigung des Verbraucherschutzes

Zusammenfassung Der Verfasser schildert die gegenwärtige Situation in der Bekämpfung von Schädlingen in deutschen Lebensmittelbetrieben, Er weist auf die Begünstigung mancher Schädlingsarten durch die Technisierung und Rationalisierung der Betriebe hin. Probleme der schriftlichen und persönlichen Beratung sowie die Organisation und Durchführung der Bekämpfung von Lebensmittelschädlingen werden eingehend besprochen, ebenso die wichtigsten Vorbeugungsmaßnahmen gegen die Einschleppung von Schädlingen unter Berücksichtigung der Einrichtung von Sicherheitsschleusen und Bestrahlungsräumen. Die zur Zeit in der Bundesrepublik üblicben Entseuchungsverfahren für ganze Betriebsanlagen werden unter Beschreibung der wichtigsten Begasungsmethoden diskutiert. Besondere Hinweise gelten der Bekämpfung eingeschleppter Schadlinge und der Vernichtung von Nagetieren. Auch die Problematik in der Beurteilung von Reklamationen wird erörtert. Darüber hinaus finden die Bestimmungen des neuen Pflanzenschutzgesetzes sowie der Höchstmengen-Verordnung — Pflanzenschutz — im Hinblick auf die Bekämpfung von Lebensmittelschädlingen besondere Berücksichtigung.

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Summary The author describes the present pest control situation in German food processing plants. He refers to the constant spread of some pests favoured by modern food processing techniques and by the rationalization of plants. Problems of advisory work carried out by personal consultation or written information as well as the organization and implementation of pest control are discussed in detail. This applies also to the principal prophylactic measures against an introduction of pests into the plant by the installation of safety sluices and radiation chambers. The disinfection methods for entire plants presently applied in the Federal Republic of Germany and the principal fumigation methods are also being described. Special recommendations are given for the control of the pests introduced and for the eradication of rodents. Furthermore, the problems relating to an assessment of reclamations are being discussed. In view of the control of pests on food special attention is paid to the regulations of the new Plant Protection Act and to the Regulations on the Maximum Quantity of Residues Tolerated on Food (Plant Protection).

     

Hydroxamic acid content of triticum species

Summary Fifty-five accessions of Triticum species were analyzed for content of hydroxamic acids (Hx), a natural resistance factor against various organisms. Hx were found in all accessions analyzed. Extreme values were found in wild diploid species: highest in T. speltoides (16.0 mmol/kg fr. wt) and lowest in T. tauschii (0.21). Modern polyploid wheats sharing the same genome did not show substantial variations in Hx levels. The data suggest possible sources of high Hx levels for wheat breeding programs.