Experimentelle Mutationsforschung bei Gerste und Ackerbohne — ausgewählte Ergebnisse der Zusammenarbeit zwischen dem Zentralinstitut in Gatersleben und dem institut für Genetik in Sofia

Zusammenfassung Es wird ein selektiver Überblick über einige Ergebnisse der Kooperation zwischen dem Zentralinstitut für Genetik und Kulturpflanzenforschung Gatersleben der AdW der DDR und dem Institut für Genetik der Bulgarischen Akademie der Wissenschaften, Sofia, zum Thema Wirkungsmechanismen und Wirkungsspezifitäten chemischer Mutagene bei Gerste undVicia faba gegeben. Die Angaben beziehen sich im wesentlichen auf Resultate, die mit Hilfe strukturell rekonstruierter Gerstenkaryotypen erzielt wurden und betreffen die ortsspezifische Wirkung chemischer Mutagene, die Chromatidenaberrationen induzieren und deren Beeinflußbarkeit durch Karyotypumbauten sowie das Phänomen der Nukleolardominanz, d. h. der cis-repressiven Wirkung nach Kombination mehrerer Nukleolusorganisatoren in einem Chromosomenpaar.

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Experimental mutagenesis in barley and broad bean — some results obtained in co-operation between the Central Institute of Genetics and Research in Cultivated Plants, Gatersleben, and the Institute of Genetics, Sofia

Summary A selective survey concerning some results obtained by co-operation in the field mechanisms and specificities of chemical mutagens in barley andVicia faba between the Institutes in Gatersleben and Sofia is given. The results summarized are based on experiments with structurally reconstructed karyotypes which allowed to study patterns of preferential involvement in chromatid aberrations of certain chromosome segments and possibilities of pattern modification by chromosome structural changes. Nucleolar dominance, i.e., cis-repression after combination of all nucleolus organizing regions (NORs) in one chromosome pair, was studied in some appropriate translocation lines and the nucleolar test used as a means of characterizing NOR-activity.

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Vortrag auf der Festveranstaltung (3. 10. 84) des ZI anläßlich des 35. Jahrestages der Gründung der DDR.     

New biologically active compounds from Kenyan propolis

From propolis samples from Kenya, two new arylnaphtalene lignans were isolated, tetrahydrojusticidin B 1 and 6-methoxydiphyllin 2, along with four known phenolic compounds 5–8, found for the first time in propolis. The structures of the compounds were elucidated based on their spectral properties. The geranylstilbenes 7 and 8 demonstrated antibacterial activity against S. aureus, and the geranylflavon macarangin 6 possessed antiradical activity against DPPH radicals.     

Fla-DGGE analysis of Campylobacter jejuni and Campylobacter coli in cecal samples of broilers without cultivation

In a commercial broiler flock during rearing multiple genotypes of Campylobacter jejuni may be present as well as in gastrointestinal tracts of individual birds. The aim of this study was to optimize and apply a denaturing gradient gel electrophoresis assay of the flagellin gene (fla-DGGE) for analysis of C. jejuni and Campylobacter coli in cecal samples of broilers without prior cultivation. One C. coli and 21 C. jejuni strains isolated from broiler flocks, of which 14 typed as unique by restriction fragment length polymorphism of flaA and two undefined strains, were clustered into 9 groups when applying fla-DGGE. Spiking of cecal samples revealed that fla-DGGE is able to detect at least 4.55-5.96logCFUCampylobacter/mlcecal material. The presence of 3 strains spiked in cecal material was demonstrated by fla-DGGE as the corresponding bands were visible on the DGGE gel. Naturally contaminated cecal samples were shown to contain different types of C. jejuni and C. coli. Fla-DGGE has some potential as a cultivation-independent fast primary subtyping method for C. jejuni and C. coli in cecal samples of broilers.     

Antimicrobial activity and cytotoxicity of Carthamus lanatus

Total dichloromethane, methanol and water extracts, their fractions as well as volatiles of Carthamus lanatus aerial parts were phytochemically screened and evaluated for antibacterial, antifungal and cytotoxic activity. The H(2)O/MeOH fraction of the CH(2)Cl(2) extract exhibited noticeable antibacterial activity. The same fraction and the volatiles showed significant cytotoxic activity.     

Standortbedingte Unterschiede bei bestäubungsökologischen Merkmalen von Wintergersten (Hordeum vulgare L. s. 1.)

Zusammenfassung In Karnobat (VR Bulgarien) und Gatersleben (DDR) wurden mit 20 Wintergerstensippen parallel dreijährige Versuche durchgeführt, um standortbedingte Unterschiede bei bestäubungsökologischen Merkmalen zu erfassen. Folgende Merkmale wurden geprüft: Antherenejektion, Antherenlänge, Antherenbreite, Stigmataspreizung, Stigmatahöhe und Stigmatafläche.Unter den klimatischen Bedingungen Karnobats neigt die Gerste mehr zur Allogamie, und die Voraussetzungen für eine Hybridsaatgutproduktion sind günstig. In Gatersleben zeigen die Gersten eine Tendenz zur Autogamie, so daß hier mit der Sortimentserhaltung weniger Probleme verbunden sind. Die Unterschiede zwischen beiden Anbauorten werden besonders auf die Lufttemperatur und die photoperiodischen Verhältnisse zurückgeführt.

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Environmental influences on characters of pollination ecology in winter barley (Hordeum vulgare L. s. l.)

Summary In Karnobat (Bulgaria) and Gatersleben (GDR) an experiment was conducted during three years (1974–1976) to demonstrate environmental influences on characters of pollination ecology in barley. The following characters were studied: anther extrusion, anther length, anther width, stigma width, stigma height and stigmatic surface area. Under the climatic conditions of Karnobat barley tends to open flowering and that's why there are good possibilities for hybrid seed production. In Gatersleben barley shows a stronger tendency to autogamy. Less problems are connected here with the maintaining of large collections. Differences between the two localities are attributed to air temperature and photoperiodic conditions mainly.

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New polyisoprenylated benzophenones from Venezuelan propolis

Two new polyisoprenylated benzophenones, 18-ethyloxy-17-hydroxy-17,18-dihydroscrobiculatone A and 18-ethyloxy-17-hydroxy-17,18-dihydroscrobiculatone B, together with the known scrobiculatones A and B, were isolated from Venezuelan propolis. The scrobiculatones A and B showed significant antibacterial activity and moderate toxicity to Artemia salina nauplii.