Nutzung von In-vitro-Pflanzen der Kartoffel zur Prüfung der antiphytoviralen Wirkung von 2,4-Dioxohexahydro-1,3,5-triazin (DHT) in Kombination mit N-Cyanoguanidin

Suitability of in vitro potato plantlets for testing of antiphytoviral effect of a combination of 2,4-dioxo-hexahydro-1,3,5-triazine (DHT) and N-cyano guanidine The suitability of a semiquantitative determination of virus content for the detection of antiphytoviral effects of chemicals was demonstrated by ELISA directly applying at in vitro potato cultures systemically infected and chemotherapeutically treated. The combination of 2, 4-dioxohexahydro-1,3,5-triazine (DHT) and N-cyanoguanidine both applied at a concentration of 0.03% to the culture medium resulted in a high significant reduction of the relative concentration of the potato virus S in the, potato genotype ‘M-812820’ of 44–73 %. A phytotoxic influence of the substances was not observed. The combination of the two antiphytoviral substances had no effect against potato virus Y in explants of the variety ‘Ackersegen’. Differences in the susc, eptibility of various genotypes against biologically active substances were indicated.     

Vergleich der Wirkung von Thymochinon und Thymohydrochinon mit der von 2,4-Dinitrophenol auf den Stoffwechsel der Hefe

Zusammenfassung Beim Vergleich der Wirkung von Thymohydrochinon und Thymochinon mit der von 2,4-DNP auf den aeroben und anaeroben Stoffwechsel der Hefe wurde eine Ähnlichkeit in der Wirkung dieser Substanz gefunden. Beim Vergleich gleicher Konzentrationen ist die Stoffwechselaktivität von 2,4-DNP größer als die von Thymohydrochinon und Thymochinon. Bei Konzentrationen, die die Atmung anregen, wird von Thymohydrochinon und Thymochinon im Gegensatz zu 2,4-DNP die Synthese der Polysaccharide nicht gehemmt.     

Antiphytovirale Wirkungen von 1,5-Diacetyl-2,4-dioxohexahydro-1,3,5-triazin (DA-DHT)*

Antiphytoviral activities of 1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine Substitution of 2,4-dioxohexahydro-1,3,5-triazine (DHT) by two acetyl groups resulted in an antiphytoviral compound, 1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine (DA-DHT), which inhibits PVX, PVY, ToMV, TMV and TRV better than DHT, but only after, application at relatively high concentrations (10^?2 mol/1). The antiphytoviral activity of DA-DHT is enhanced by combined treatments with DHT as well as with cyanoguanidine, sodiumalkanemonosulfonate and 2-anilino-5-adamantyl-1,3,4-thiadiazole., DA-DHT reduced the number of symptoms of PLRV bearing potato eye cutting plants to a higher percentage than DHT. But the highest reduction was brought about by combined treatments with DA-DHT, cyanoguanidine, sodiumalkanemonosulfonate and 2-anilino-5-adamantyl-1,3,5-thiadiazole. Moreover, treatments with DA-DHT increased more than treatments with DHT the mass of potato tubers produced by potato eye cutting plants. Combined treatments with DA-DHT and the above mentioned substances reduced the natural infection with PLRV of a completely healthy potato stock for about 70 % and that of PVY for about 40 %. Thus, the DA-DHT containing preparations may be capable of keeping potatoes in a good state of health even in regions with a high infection pressure.     

Einfluß der Behandlung von Rübensaatgut mit Rhizosphärebakterien auf den Befall durch Pilze der Gattung Pythium I. Antagonistische Wirkung verschiedener Bakterienisolate gegenüber Pythium spp.

Abstract The influence of a seed-dressing with rhizosphere bacteria on the infection of sugarbeet by fungi of the genus Pythium I. Antagonistic effect of different bacterial isolates towards Pythium spp.
Seed treatment with selectively isolated rhizosphere bacteria from the fluorescent pseudomonad group can protect sugar beet seedlings from damping-off caused by species of Pythium. The antagonistic rhizobacteria were equally effective in different soil substrates, both unsterilized and steam-sterilized. Antagonistic activity of an isolate was similar within seeds of a sugarbeet cultivar but different when different cultivars were compared. The number of bacteria adhering to the seed of eachcultivar which influenced the level of antagonism to Pythium infection, varied with seed morphology. A mixture of the three different isolates did not increase antagonistic activity when compared to the activity of the isolates individually.     

Die Simulation quantitativer Merkmale durch Gene mit biochemisch definierbarer Wirkung

Summary With reference to the concentration of aglycones in carefully hydrolysed anthocyanin extracts of 16 genotypes of Matthiola incana R.Br. it was investigated whether the measurement of the optical density of qualitatively different anthocyanin extracts may pass as a suitable measurement of the total content of anthocyanin pigments. — The results obtained after acid hydrolysis of different anthocyanin extracts show that the qualitative change of the pigment pattern influences in some cases the extinction values considerably. Thus, 3-mono-sides and 3-biosides were underestimated, whereas 3, 5-glycosides were overestimated. The acylation of the anthocyanin molecule seems to have a detectable influence only on the 3, 5-triglycosides. — The results obtained could be confirmed largely by comparison with purchased preparations and are in accordance with the coefficients of extinction we measured and those found in literature. From these results correction factors may be derived which are suited to transforming the extinction values obtained by measurements of the optical density to the same scale. — The influence of this transformation on the distribution of measurements and on the estimates of the parameters of the genes involved was examined by means of a formerly investigated trifactorial system.Zusammenfassung Anhand der Konzentration des Aglycons in schonend hydrolysierten Anthocyanextrakten von 16 Genotypen der Sommerlevkoje, Matthiola incana R.Br. wurde untersucht, ob die Messung der optischenDichte qualitativ unterschiedlicher Anthocyanextrakte als geeignetes Maß für den Gesamtgehalt der Anthocyanpigmente gelten kann. — Die nach saurer Hydrolyse der verschiedenen Anthocyanextrakte erhaltenen Ergebnisse zeigen, daß qualitative Änderungen des Pigmentmusters in einigen Fällen die Extinktionswerte erheblich beeinflussen. So werden 3-Monoside und 3-Bioside bei Extinktionsmessungen in ihrer Konzentration unterbewertet wogegen 3, 5-Glycoside überbewertet werden. Die Acylierung der Anthocyanmoleküle scheint nur bei den 3, 5-Triglycosiden einen nachweisbaren Einfluß zu haben. — Die erhaltenen Ergebnisse konnten anhand von Handelspräparaten weitgehend bestätigt werden und stehen auch in guter Übereinstimmung mit selbst bestimmten und in der Literatur veröffentlichten molaren Extinktionskoeffizienten. — Aus den Ergebnissen lassen sich Korrekturfaktoren ableiten, die geeignet sind, die bei Messungen der optischen Dichte erhaltenen Extinktionswerte in eine miteinander vergleichbare Form zu überführen. — An den Meßwerten eines früher untersuchten trifaktoriellen Systems wurde die Auswirkung der Korrekturen auf die Verteilung der Meßwerte und auf die Parameterschätzwerte der beteiligten Gene geprüft.

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Angenommen durch W. Seyffert     

Steigerung der keimungshemmenden Wirkung von Abscisinsäure auf Lactuca-Früchte durch Saccharose und Glucose

Summary Some sugars, especially sucrose and glucose, and some inorganic salts have been found to enhance in low concentrations the germination inhibiting effect of abscisic acid (ABA) in lettuce. There is evidence from gas chromatographic analysis and from bioassays of seed extracts that this stimulation is due to increased uptake of ABA from solution in the presence of glucose and sucrose.     

Einfluß der Behandlung von Rübensaatgut mit Rhizosphärebakterien auf den Befall durch Pilze der Gattung Pythium II. Untersuchungen zum Wirkungsmechanismus

Abstract The influence of a seed-dressing with rhizosphere bacteria on the infection of sugarbeet by fungi of the genus Pythium II. Studies on the mode of action
Studies were conducted to determine the mode of action responsible for the reduction of Pythium infection of sugarbeet seedlings caused by an inoculation with rhizosphere bacteria. It was shown that the bacteria reduced Pythium ultimum , sporangia germination. More detailed studies with the bacterial isolate T58 demonstrated that activity was related to both presence of the living bacteria as well as to inoculum density.
Water soluble extracts from the seed of different sugarbeet cultivars stimulated P. ultimum sporangia germination to different degrees, Germination, however, decreased as the density of the fluorescent pscudomonad T58 was increased. Reductions in mycelial growth, caused by a number of isolates, indicated the presence of antibiotic activity.
The addition of high levels of iron to the substrate caused a reduction in the level of antagonism of two pseudomonad isolates on the seed of the cultivar Kawevera. The rate of reproduction of two bacterial isolates was slower on extracts from the seeds of the cultivar Primahill than on the cultivar Kawevera. Rhizobacteria colonization of the root as well as the hypocotyl was observed with one isolate.     

Die mutagene Wirkung von Endoxan bei der Maus

1. 1.
   Dosages of 420 mg and 210 mg Endoxan (Cyclophosphamid, Cytoxan) per kg body weigt were injected intraperitoneally into male C3H mice immediately before mating them with virgin females. The high dose led to sterility and to death of all males within the second week after treatment. The smaller quantity of Endoxan induced dominant lethal mutations, that is increased pre- and post-implantation death rates.